In office automation workflows, you often need to batch-extract product images from Excel reports, replace outdated logos, or export a specific image individually. Spire.XLS for JavaScript handles all of these image operations directly in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server is required.

This article covers three core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Extract All Images from a Worksheet

Batch-extracting all images from a worksheet is useful for backing up embedded images in reports, migrating product materials, and similar scenarios. The process consists of three steps: iterate over the Worksheet.Pictures collection, call the Picture.Save method on each image to save it to the VFS, then read each file and trigger a browser download.

function App() {
  const extractAllImages = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the Excel file into VFS
    const inputFileName = 'ReadImages.xlsx';
    await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Load the workbook and get the first worksheet
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: inputFileName });
    const sheet = workbook.Worksheets.get(0);

    // Iterate through all pictures in the worksheet and export each one
    for (let i = 0; i < sheet.Pictures.Count; i++) {
      const pic = sheet.Pictures.get(i);
      const outputFileName = `Image-${i + 1}.png`;
      pic.Picture.Save(outputFileName);

      // Read the exported image file from VFS and trigger download
      const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
      const blob = new Blob([fileArray], { type: "image/png" });
      const url = URL.createObjectURL(blob);
      const a = document.createElement('a');
      a.href = url;
      a.download = outputFileName;
      a.click();
      URL.revokeObjectURL(url);
    }

    // Release resources
    workbook.Dispose();
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Extract All Images from Worksheet</h1>
      <button onClick={extractAllImages}>
        Extract All Images
      </button>
    </div>
  );
}

export default App;

Image files extracted and downloaded from the worksheet in batch

Image files extracted and downloaded from the worksheet in batch


Extract a Specific Image

There are two common ways to extract a specific image from a worksheet: retrieve it directly by index, or iterate through pictures by name to find a match. The index approach suits scenarios where the picture position is known (for example, the first picture), while the name approach is better when you know the picture identifier in advance. The process consists of two steps: first locate the target image by index or name, then export it as a local file.

function App() {
  const extractImage = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the Excel file into VFS
    const inputFileName = 'ReadImages.xlsx';
    await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Load the workbook and get the first worksheet
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: inputFileName });
    const sheet = workbook.Worksheets.get(0);

    // Method 1: Extract by index (e.g., extract the second picture)
    const pic = sheet.Pictures.get(1);
    const outputFileName = 'ExtractByIndex.png';

    // // Method 2: Iterate through pictures by name to find a match
    // let pic = null;
    // const targetName = 'SpireXLS';
    // for (let i = 0; i < sheet.Pictures.Count; i++) {
    //   if (sheet.Pictures.get(i).Name === targetName) {
    //     pic = sheet.Pictures.get(i);
    //     break;
    //   }
    // }
    // const outputFileName = 'ExtractByName.png';

    // Save the picture to VFS and trigger download
    pic.Picture.Save(outputFileName);
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: "image/png" });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);

    workbook.Dispose();
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Extract a Specific Image</h1>
      <button onClick={extractImage}>
        Extract Image
      </button>
    </div>
  );
}

export default App;

Specific image extracted and downloaded by index or name

Specific image extracted and downloaded by index or name


Replace an Existing Image in a Worksheet

Replacing an existing image in a worksheet is a common requirement when updating report logos, changing product display images, and in similar scenarios. The approach is to first retrieve the position and size information of the target image, then delete it via XlsShape.Convert, and finally insert a new image at the same position, setting the new image's size and offsets to match the original.

function App() {
  const replaceImage = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the Excel file and the new image into VFS
    const inputFileName = 'ReadImages.xlsx';
    await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}data/`);
    const newImageFile = 'Logo.png';
    await window.spire.FetchFileToVFS(newImageFile, '', `${process.env.PUBLIC_URL}data/`);

    // Load the workbook and get the first worksheet
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: inputFileName });
    const sheet = workbook.Worksheets.get(0);

    // Get the first picture and its position and size information
    const oldPic = sheet.Pictures.get(0);
    const topRow = oldPic.TopRow;
    const leftColumn = oldPic.LeftColumn;
    const leftColumnOffset = oldPic.LeftColumnOffset;
    const topRowOffset = oldPic.TopRowOffset;
    const width = oldPic.Width;
    const height = oldPic.Height;

    // Delete the original picture
    xlsModule.XlsShape.Convert(oldPic).Remove();

    // Insert the new picture at the same position
    let picture = sheet.Pictures.Add({ topRow: topRow, leftColumn: leftColumn, fileName: newImageFile });

    // Set the new picture's size and offsets to match the original
    picture.Width = width;
    picture.Height = height;
    picture.LeftColumnOffset = leftColumnOffset;
    picture.TopRowOffset = topRowOffset;

    const outputFileName = 'ReplaceImage-out.xlsx';
    // Save the modified workbook
    workbook.SaveToFile({ fileName: outputFileName, version: xlsModule.ExcelVersion.Version2010 });
    // Release resources
    workbook.Dispose();

    // Read the generated file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Replace Image in Worksheet</h1>
      <button onClick={replaceImage}>
        Replace Image
      </button>
    </div>
  );
}

export default App;

The Excel worksheet after the image is replaced

The Excel worksheet after the image is replaced


FAQ

Extracted images cannot be opened or the format is incorrect

Cause: The correct file extension was not specified when saving the image, or the MIME type does not match the image format.

Solution: Make sure the file extension used in the Picture.Save method matches the actual image format. If the image is in PNG format, the file extension should be .png; if it is in JPEG format, use .jpg. The Blob type used for the download should be set accordingly:

// PNG format
const blob = new Blob([fileArray], { type: "image/png" });

// JPEG format
const blob = new Blob([fileArray], { type: "image/jpeg" });

The position or size of the image changes after replacement

Cause: The position and size properties of the original image were not recorded before deletion, so the new image cannot be precisely aligned to the original position or retain its original size.

Solution: Save the position properties such as TopRow, LeftColumn, LeftColumnOffset, TopRowOffset and the size properties Width, Height before deleting the image. After inserting the new image, set these properties on the new picture so it matches the original:

// Insert the new picture (specify the row and column position)
let picture = sheet.Pictures.Add({ topRow: topRow, leftColumn: leftColumn, fileName: newImageFile });

// Set size and offsets to match the original
picture.Width = width;
picture.Height = height;
picture.LeftColumnOffset = leftColumnOffset;
picture.TopRowOffset = topRowOffset;

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

OFD (Open Fixed-layout Document) is a national standard fixed-layout document format widely used in e-invoices, e-certificates, administrative approvals, and other government and financial scenarios. OFD describes document structure based on XML, offering advantages such as independent control and information security. Meanwhile, PDF remains indispensable as an internationally recognized document format for cross-platform distribution. Real-world business often requires flexible switching between the two formats: receiving OFD-format e-invoices and converting them to PDF for printing and distribution, or converting existing PDF contracts to OFD to meet government platform upload requirements.

Spire.PDF for JavaScript performs bidirectional conversion between PDF and OFD entirely in the browser via WebAssembly, managing input and output files through a virtual file system (VFS) with no backend server required.

This article covers two core features:

For installation and project setup, refer to Integrating Spire.PDF for JavaScript in a React Project. The examples below assume Spire.PDF is installed and the WebAssembly module is initialized.


Convert PDF to OFD

The core of PDF-to-OFD conversion is to re-encode the page content, fonts, and graphics elements from a PDF document into an XML description structure compliant with the OFD standard. Spire.PDF for JavaScript accomplishes this in one step through the PdfDocument object's SaveToFile method with the FileFormat.OFD enum value, eliminating the need to handle underlying format differences manually.

function App() {
  const convertToOFD = async () => {
    // Get the Spire.PDF WASM module
    const pdfModule = window.wasmModule?.spirepdf;

    // Check if the WASM module is ready
    if (!pdfModule) {
      alert('Spire.PDF is not ready yet');
      return;
    }

    // Load fonts and PDF file into VFS
    await window.spire.FetchFileToVFS('ARIAL.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/font/`);
    const inputFileName = 'TemplateIntroduction-en.pdf';
    await window.spire.FetchFileToVFS(inputFileName, "", `${process.env.PUBLIC_URL}/data/`);

    // Create PdfDocument object and load the PDF document
    let doc = new pdfModule.PdfDocument();
    doc.LoadFromFile(inputFileName);

    // Define the output file name for OFD format
    const outputFileName = 'OutputOFD.ofd';

    // Save as OFD format
    doc.SaveToFile({ fileName: outputFileName, fileFormat: pdfModule.FileFormat.OFD });
    doc.Close();

    // Read the converted file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/ofd' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Convert PDF To OFD</h1>
      <button onClick={convertToOFD}>
        Generate
      </button>
    </div>
  );
}

export default App;

OFD output generated after conversion via SaveToFile with FileFormat.OFD

OFD output generated after conversion via SaveToFile with FileFormat.OFD


Convert OFD to PDF

OFD-to-PDF conversion is a common requirement in government electronic document distribution scenarios. Spire.PDF for JavaScript provides the OfdConverter component, which is specifically designed to parse OFD fixed-layout documents and export them as standard PDF files while preserving the original document's layout and visual appearance.

function App() {
  const convertOFDToPDF = async () => {
    // Get the Spire.PDF WASM module
    const pdfModule = window.wasmModule?.spirepdf;

    // Check if the WASM module is ready
    if (!pdfModule) {
      alert('Spire.PDF is not ready yet');
      return;
    }

    // Load fonts and OFD file into VFS
    await window.spire.FetchFileToVFS('Arial.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/font/`);
    const inputFileName = 'Invoice_EN.ofd';
    await window.spire.FetchFileToVFS(inputFileName, "", `${process.env.PUBLIC_URL}/data/`);

    // Create OfdConverter object and pass the OFD file path
    let converter = new pdfModule.OfdConverter(inputFileName);
    
    // Define the output file name for PDF format
    const outputFileName = 'OutputPDF.pdf';

    // Convert to PDF format
    converter.ToPdf(outputFileName);
    converter.Dispose();

    // Read the converted file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/pdf' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Convert OFD To PDF</h1>
      <button onClick={convertOFDToPDF}>
        Generate
      </button>
    </div>
  );
}

export default App;

Standard PDF output generated after conversion via OfdConverter

Standard PDF output generated after conversion via OfdConverter


FAQ

Can encrypted PDFs be converted to OFD?

Password-protected encrypted PDFs cannot be saved as OFD directly via SaveToFile — the document must be decrypted first.

Solution: Provide the password when loading the PDF via the second parameter of LoadFromFile, then save as OFD:

// Load a password-protected PDF document
let doc = new pdfModule.PdfDocument();
doc.LoadFromFile(inputFileName, "password");

// Save as OFD format
doc.SaveToFile({ fileName: outputFileName, fileFormat: pdfModule.FileFormat.OFD });
doc.Close();

Garbled text in the converted OFD document

OFD relies on font embedding to ensure consistent cross-platform rendering. If the input PDF uses non-embedded fonts and the corresponding font files are not loaded in the VFS, text may appear garbled after conversion.

Solution: Make sure the required TrueType font files (e.g., ARIALUNI.TTF) are loaded into the /Library/Fonts/ directory in VFS before calling the conversion. ARIALUNI.TTF covers common CJK characters and is the recommended font for ensuring conversion quality.


Get a Free License

Spire.PDF for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Data labels are an essential element of Excel charts for displaying detailed information about data points, such as values, series names, and category names. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server required. It provides a complete API for controlling data label display content, font formatting, number format, position, background, borders, and other appearance properties.

This article covers two core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Set Data Label Content and Font

Data labels can display various types of information, including values, series names, category names, and legend keys. With Spire.XLS for JavaScript, you can flexibly control the display content of data labels and customize their font styles to make the chart information clearer and more readable. The steps are as follows:

  1. Create a Workbook object and get the default worksheet.
  2. Populate the worksheet with category labels and numeric data for the chart.
  3. Add a chart using sheet.Charts.Add() and set the chart type.
  4. Configure the chart's data range, position, and title.
  5. Enable data label display content (values, series names, category names) via the DataLabels property.
  6. Set data label font properties (font name, size, color, bold, etc.).
  7. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to set chart data label content and font in React:

function App() {
  const setDataLabelContentAndFont = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a new workbook and get the default worksheet
    const workbook = new xlsModule.Workbook();
    let sheet = workbook.Worksheets.get(0);
    sheet.Name = "DataLabelDemo";

    // Populate chart data
    sheet.Range.get("A1").Value = "Month";
    sheet.Range.get("A2").Value = "Jan";
    sheet.Range.get("A3").Value = "Feb";
    sheet.Range.get("A4").Value = "Mar";
    sheet.Range.get("A5").Value = "Apr";
    sheet.Range.get("A6").Value = "May";
    sheet.Range.get("A7").Value = "Jun";

    sheet.Range.get("B1").Value = "Sales";
    sheet.Range.get("B2").NumberValue = 25;
    sheet.Range.get("B3").NumberValue = 18;
    sheet.Range.get("B4").NumberValue = 8;
    sheet.Range.get("B5").NumberValue = 13;
    sheet.Range.get("B6").NumberValue = 22;
    sheet.Range.get("B7").NumberValue = 28;

    // Add a line chart and set its data range
    let chart = sheet.Charts.Add({ chartType: xlsModule.ExcelChartType.LineMarkers });
    chart.DataRange = sheet.Range.get("B1:B7");
    chart.SeriesDataFromRange = false;

    // Set the chart position
    chart.TopRow = 5;
    chart.BottomRow = 26;
    chart.LeftColumn = 2;
    chart.RightColumn = 11;

    // Configure chart title
    chart.ChartTitle = "Data Labels Demo";
    chart.ChartTitleArea.IsBold = true;
    chart.ChartTitleArea.Size = 12;

    // Bind category labels
    let cs1 = chart.Series.get(0);
    cs1.CategoryLabels = sheet.Range.get("A2:A7");

    // Set data label display content: show values, series names, and category names
    cs1.DataPoints.DefaultDataPoint.DataLabels.HasValue = true;
    cs1.DataPoints.DefaultDataPoint.DataLabels.HasSeriesName = true;
    cs1.DataPoints.DefaultDataPoint.DataLabels.HasCategoryName = true;

    // Set data label delimiter
    cs1.DataPoints.DefaultDataPoint.DataLabels.Delimiter = ". ";

    // Customize data label font styles
    cs1.DataPoints.DefaultDataPoint.DataLabels.Size = 9;
    cs1.DataPoints.DefaultDataPoint.DataLabels.Color = xlsModule.Color.get_Red();
    cs1.DataPoints.DefaultDataPoint.DataLabels.FontName = "Calibri";
    cs1.DataPoints.DefaultDataPoint.DataLabels.IsBold = true;

    // Save the workbook
    const outputFileName = 'DataLabelContentAndFont.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Set Data Label Content and Font</h1>
      <button onClick={setDataLabelContentAndFont}>
        Generate
      </button>
    </div>
  );
}

export default App;

Data label content and font set with Spire.XLS for JavaScript

Data label content and font set with Spire.XLS for JavaScript


Adjust Data Label Position and Appearance

Beyond display content and font styles, the position and appearance of data labels are also important aspects of chart visual enhancement. Spire.XLS for JavaScript supports adjusting the display position of data labels through the DataLabelPositionType enumeration, and allows you to set fill colors, border styles, and shadow effects for data labels. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file containing a chart.
  2. Get the worksheet via workbook.Worksheets.get().
  3. Get the chart object using sheet.Charts.get().
  4. Iterate through the chart's data series and set the data label position using DataLabels.Position.
  5. Set a background fill color for the data labels via FrameFormat.Fill.
  6. Set border color and style for the data labels via FrameFormat.Border.
  7. Add shadow effects to data labels via FrameFormat.Shadow (type, color, transparency, size, blur, angle, and distance).
  8. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to adjust chart data label position and appearance in React:

function App() {
  const setDataLabelPositionAndAppearance = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into the virtual file system (VFS)
    let excelFileName = 'SampleChart.xlsx';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a workbook object and load the existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });

    // Get the first worksheet
    let sheet = workbook.Worksheets.get(0);

    // Get the first chart
    let chart = sheet.Charts.get(0);

    // Iterate through all data series and adjust data label position and appearance
    for (let i = 0; i < chart.Series.Count; i++) {
      let cs = chart.Series.get(i);
      // Set data point marker style and size to make data points more prominent
      cs.DataFormat.MarkerSize = 6;
      cs.DataFormat.MarkerStyle = xlsModule.ChartMarkerType.Circle;
      cs.DataFormat.MarkerForegroundColor = xlsModule.Color.get_Blue();
      cs.DataFormat.MarkerBackgroundColor = xlsModule.Color.get_White();
      
      let dataLabels = cs.DataPoints.DefaultDataPoint.DataLabels;

      // Enable value labels
      dataLabels.HasValue = true;

      // Set data label position
      dataLabels.Position = xlsModule.DataLabelPositionType.Right;

      // Set data label font color and size
      dataLabels.Color = xlsModule.Color.get_Blue();
      dataLabels.Size = 10;

      // Set pink fill background
      dataLabels.FrameFormat.Fill.FillType = xlsModule.ShapeFillType.SolidColor;
      dataLabels.FrameFormat.ForeGroundColor = xlsModule.Color.get_Pink();

      // Set red border
      dataLabels.FrameFormat.Border.Pattern = xlsModule.ChartLinePatternType.Solid;
      dataLabels.FrameFormat.Border.Color = xlsModule.Color.get_Red();

      // Set yellow shadow effect
      dataLabels.FrameFormat.Shadow.ShadowOuterType = xlsModule.XLSXChartShadowOuterType.OffsetDiagonalBottomLeft;
      dataLabels.FrameFormat.Shadow.Color = xlsModule.Color.get_Yellow();
      dataLabels.FrameFormat.Shadow.Transparency = 0;
      dataLabels.FrameFormat.Shadow.Size = 10;
      dataLabels.FrameFormat.Shadow.Blur = 2;
      dataLabels.FrameFormat.Shadow.Angle = 45;
      dataLabels.FrameFormat.Shadow.Distance = 8;
    }

    // Save the workbook
    const outputFileName = 'DataLabelPositionAndAppearance.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Set Data Label Position and Appearance</h1>
      <button onClick={setDataLabelPositionAndAppearance}>
        Generate
      </button>
    </div>
  );
}

export default App;

Data label position and appearance adjusted with Spire.XLS for JavaScript

Data label position and appearance adjusted with Spire.XLS for JavaScript


FAQ

How to modify the label content of a specific data point instead of the entire series?

Cause: DefaultDataPoint.DataLabels applies to all data points in a series and cannot control individual data points separately.

Solution: Use DataPoints.get(index) to access a specific data point and set its label:

// Modify the label text of the third data point
chart.Series.get(0).DataPoints.get(2).DataLabels.Text = "Peak";
chart.Series.get(0).DataPoints.get(2).DataLabels.HasValue = false;

How to set number format for data labels (decimal places, currency symbols)

Cause: The number format of data labels matches the cell format by default, but sometimes needs to be controlled independently.

Solution: Use the DataLabels.NumberFormat property to customize the number format:

// Show two decimal places
dataLabels.NumberFormat = "0.00";
// Display as percentage
dataLabels.NumberFormat = "0.0%";
// Display with currency symbol
dataLabels.NumberFormat = "$#,##0";

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

In daily office work, data often needs to be exchanged between Excel spreadsheets and plain text (TXT) files. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server is required. It provides flexible APIs for controlling conversion parameters such as delimiters and encoding formats.

With Spire.XLS for JavaScript, you can export Excel worksheet data as structured text files, or import delimited text files to create fully formatted Excel workbooks. This makes data migration between different applications more convenient and efficient.

This article covers two core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Convert Excel Worksheet Data to TXT

Exporting Excel data as a plain text file makes it convenient for further processing or analysis in other applications. With Spire.XLS for JavaScript, you can save the contents of a specified worksheet as a TXT file, with flexible control over the field separator and character encoding. The steps are as follows:

  • Create a Workbook object and load an existing Excel file.
  • Retrieve a specific worksheet via workbook.Worksheets.get(index).
  • Call the worksheet's SaveToFile() method, specifying the output filename, separator, and encoding.
  • Dispose of the workbook resources, read the result file from VFS, and trigger the download.

Below is a complete code example demonstrating how to convert Excel to TXT in React:

function App() {
  const convertToText = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    // Create a workbook object and load the Excel file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });

    // Get the first worksheet
    let sheet = workbook.Worksheets.get(0);

    // Save the worksheet as a TXT file with space separator and UTF-8 encoding
    const outputFileName = 'ExcelToTxt.txt';
    sheet.SaveToFile({
      fileName: outputFileName,
      separator: " ",
      encoding: xlsModule.Encoding.get_UTF8()
    });
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'text/plain' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Convert Excel to TXT</h1>
      <button onClick={convertToText}>
        Generate
      </button>
    </div>
  );
}

export default App;

Excel converted to TXT with Spire.XLS for JavaScript

Excel converted to TXT with Spire.XLS for JavaScript


Convert TXT File to Excel Workbook

Importing a delimited text file into an Excel spreadsheet allows you to take full advantage of Excel's formatting, calculation, and charting capabilities. Spire.XLS for JavaScript supports TXT-to-Excel conversion by reading the text file content and writing data to the workbook cell by cell. Formatting such as bold headers can also be applied during the process. The steps are as follows:

  • Load the font file and TXT sample file into the VFS.
  • Read the TXT file content from VFS, split it by lines, and parse the cell data for each line.
  • Create a Workbook object, iterate through the data array, and write data to worksheet cells row by row and column by column.
  • Apply bold styling to the header row and call AllocatedRange.AutoFitColumns() to auto-fit column widths.
  • Save the workbook as an Excel file and trigger the download.

Below is a complete code example demonstrating how to convert TXT to Excel in React:

function App() {
  const convertToExcel = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the font file to ensure proper text rendering
    await window.spire.FetchFileToVFS('ARIAL.TTF', '', `${process.env.PUBLIC_URL}font/`);

    // Load the TXT file into VFS
    await window.spire.FetchFileToVFS('Sample.txt', '', `${process.env.PUBLIC_URL}data/`);

    // Read the text file content from VFS
    const txtData = window.dotnetRuntime.Module.FS.readFile('Sample.txt');
    const text = typeof txtData === 'string' ? txtData : new TextDecoder('utf-8').decode(txtData);

    // Split by lines, compatible with \r\n and \n
    const lines = text.trim().split(/\r?\n/);

    // Parse each line of data (try tab delimiter first, then fallback to other delimiters)
    const data = [];
    for (const line of lines) {
      const trimmed = line.trim();
      if (!trimmed) continue;
      let cells = trimmed.split('\t');
      if (cells.length === 1) {
        cells = trimmed.split(/\s+/);
      }
      data.push(cells);
    }

    // Create a Workbook object
    const workbook = new xlsModule.Workbook();

    // Get the first worksheet
    const sheet = workbook.Worksheets.get(0);

    // Iterate through rows and columns in the data array and write to cells
    for (let row = 0; row < data.length; row++) {
      for (let col = 0; col < data[row].length; col++) {
        const cell = sheet.get_Item(row + 1, col + 1);
        cell.Value = data[row][col];
        // Bold the header row
        if (row === 0) {
          cell.Style.Font.IsBold = true;
        }
      }
    }

    // Auto-fit column widths
    sheet.AllocatedRange.AutoFitColumns();

    // Save the workbook and release resources
    const outputFileName = 'TxtToExcel.xlsx';
    workbook.SaveToFile({ fileName: outputFileName, version: xlsModule.ExcelVersion.Version2010 });
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Convert TXT to Excel</h1>
      <button onClick={convertToExcel}>
        Generate
      </button>
    </div>
  );
}

export default App;

TXT converted to Excel with Spire.XLS for JavaScript

TXT converted to Excel with Spire.XLS for JavaScript


FAQ

How to handle encoding issues during conversion?

Cause: The TXT file in this example uses UTF-8 encoding. If the TXT file uses a different encoding format (such as GBK, GB2312, etc.), decoding it directly with TextDecoder('utf-8') will result in garbled text.

Solution: Specify the corresponding encoding type in the TextDecoder constructor parameter based on the actual encoding of the TXT file:

// UTF-8 encoding
const text = new TextDecoder('utf-8').decode(txtData);

// GBK encoding
const text = new TextDecoder('gbk').decode(txtData);

// GB2312 encoding
const text = new TextDecoder('gb2312').decode(txtData);

// UTF-16 encoding
const text = new TextDecoder('utf-16').decode(txtData);

How to handle TXT files with different delimiters?

Cause: TXT files may use different delimiters such as tabs (\t), spaces, commas (,), semicolons (;), etc. Choosing the wrong delimiter can lead to data parsing errors.

Solution: In JavaScript, you can specify different delimiters by modifying the parameter of the split() method:

// Tab delimiter
let cells = trimmed.split('\t');

// Comma delimiter
let cells = trimmed.split(',');

// Semicolon delimiter
let cells = trimmed.split(';');

// Regular expression: split by one or more whitespace characters (spaces, tabs, etc.)
let cells = trimmed.split(/\s+/);

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Hiding and unhiding rows and columns is a common feature in daily office work. It helps protect sensitive information, simplify data views, or temporarily conceal unnecessary data. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server required. It provides a simple API for controlling the visibility of rows and columns.

This article covers four core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Hide Specific Rows and Columns in Excel

Hiding specific rows and columns can keep your worksheet cleaner and more readable without compromising data integrity. Spire.XLS for JavaScript supports hiding a specific row or column using the HideRow() and HideColumn() methods. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file containing data.
  2. Use worksheet.HideRow() to hide a specific row.
  3. Use worksheet.HideColumn() to hide a specific column.
  4. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to hide specific rows and columns in Excel in React:

function App() {
  const hideSpecificRowsAndColumns = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into the virtual file system (VFS)
    let excelFileName = 'Sample.xlsx';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a workbook object and load the existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });
    let sheet = workbook.Worksheets.get(0);

    // Hide a specific row (row 4)
    sheet.HideRow(4);

    // Hide a specific column (column 2, i.e., column B)
    sheet.HideColumn(2);

    // Save the workbook
    const outputFileName = 'HideSpecificRowsColumns.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Hide Specific Rows and Columns</h1>
      <button onClick={hideSpecificRowsAndColumns}>
        Generate
      </button>
    </div>
  );
}

export default App;

Specific rows and columns hidden with Spire.XLS for JavaScript

Specific rows and columns hidden with Spire.XLS for JavaScript


Unhide Specific Rows and Columns in Excel

When you need to view or edit specific hidden data, you can unhide a particular row or column individually. Spire.XLS for JavaScript supports unhiding a specific row or column using the ShowRow() and ShowColumn() methods. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file containing hidden rows/columns.
  2. Use sheet.ShowRow() to unhide a specific row.
  3. Use sheet.ShowColumn() to unhide a specific column.
  4. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to unhide specific rows and columns in Excel in React:

function App() {
  const unhideSpecificRowsAndColumns = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into the virtual file system (VFS)
    let excelFileName = 'HideSpecificRowsColumns.xlsx';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a workbook object and load the existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });

    // Get the first worksheet
    let sheet = workbook.Worksheets.get(0);

    // Unhide a specific row (row 4)
    sheet.ShowRow(4);

    // Unhide a specific column (column 2, i.e., column B)
    sheet.ShowColumn(2);

    // Save the workbook
    const outputFileName = 'UnhideSpecificRowsColumns.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Unhide Specific Rows and Columns</h1>
      <button onClick={unhideSpecificRowsAndColumns}>
        Generate
      </button>
    </div>
  );
}

export default App;

Specific rows and columns unhidden with Spire.XLS for JavaScript

Specific rows and columns unhidden with Spire.XLS for JavaScript


Hide Multiple Rows and Columns at Once in Excel

When there are multiple rows or columns that you don't need to display, hiding them one by one is inefficient. Spire.XLS for JavaScript supports hiding multiple rows and columns at once through loops, greatly improving operational efficiency. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file containing data.
  2. Use a loop to call worksheet.HideRow() to hide multiple rows at once.
  3. Use a loop to call worksheet.HideColumn() to hide multiple columns at once.
  4. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to hide multiple rows and columns at once in Excel in React:

function App() {
  const hideMultipleRowsAndColumns = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into the virtual file system (VFS)
    let excelFileName = 'Sample.xlsx';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a workbook object and load the existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });
    let sheet = workbook.Worksheets.get(0);

    // Hide multiple rows at once (rows 6 through 10)
    for (let i = 6; i <= 10; i++) {
      sheet.HideRow(i);
    }

    // Hide multiple columns at once (columns 4 through 5, i.e., columns D to E)
    for (let j = 4; j <= 5; j++) {
      sheet.HideColumn(j);
    }

    // Save the workbook
    const outputFileName = 'HideMultipleRowsColumns.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Hide Multiple Rows and Columns</h1>
      <button onClick={hideMultipleRowsAndColumns}>
        Generate
      </button>
    </div>
  );
}

export default App;

Multiple rows and columns hidden at once with Spire.XLS for JavaScript

Multiple rows and columns hidden at once with Spire.XLS for JavaScript


Unhide All Hidden Rows and Columns in Excel

To unhide all hidden rows and columns, iterate through the rows and columns in the worksheet, use GetRowIsHide() and GetColumnIsHide() to find hidden ones, then call ShowRow() and ShowColumn() to unhide them. The steps are as follows:

  1. Create a Workbook object and load the Excel file.
  2. Get the worksheet.
  3. Iterate through rows, use GetRowIsHide() to find hidden rows, use ShowRow() to unhide.
  4. Iterate through columns, use GetColumnIsHide() to find hidden columns, use ShowColumn() to unhide.
  5. Save the result file using SaveToFile().

Below is a complete code example demonstrating how to unhide all hidden rows and columns in Excel in React:

function App() {
  const unhideAllRowsAndColumns = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into the virtual file system (VFS)
    let excelFileName = 'HideMultipleRowsColumns.xlsx';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a workbook object and load the existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });

    // Get the first worksheet
    let sheet = workbook.Worksheets.get(0);

    for (let i = 1; i <= sheet.Rows.length; i++) {
      if (sheet.GetRowIsHide(i)) {
        // Unhide row
        sheet.ShowRow(i);
      }
    }

    for (let j = 1; j <= sheet.Columns.length; j++) {
      if (sheet.GetColumnIsHide(j)) {
        // Unhide column
        sheet.ShowColumn(j);
      }
    }
    
    // Save the workbook
    const outputFileName = 'UnhideAllRowsColumns.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Unhide All Rows and Columns</h1>
      <button onClick={unhideAllRowsAndColumns}>
        Generate
      </button>
    </div>
  );
}

export default App;

All hidden rows and columns unhidden with Spire.XLS for JavaScript

All hidden rows and columns unhidden with Spire.XLS for JavaScript


FAQ

How to check whether a row or column is hidden?

Solution: Use the GetRowIsHide() and GetColumnIsHide() methods to check:

// Check if row 3 is hidden
let rowIsHidden = sheet.GetRowIsHide(3);

// Check if column 2 (column B) is hidden
let columnIsHidden = sheet.GetColumnIsHide(2);

Are row heights or column widths preserved after hiding?

Solution: When hiding rows or columns, the original row height and column width values are preserved. After unhiding with ShowRow() or ShowColumn(), the original dimensions are automatically restored without any additional configuration.


Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Excel document properties — such as title, author, category, and other metadata — are essential for file management and information retrieval. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files. It provides a complete API for accessing and managing both DocumentProperties (standard/built-in properties) and CustomDocumentProperties (user-defined name-value pairs).

Spire.XLS categorizes document properties into two types: standard and custom. Standard document properties are predefined built-in metadata like title, subject, author, category, keywords, and comments. Custom document properties are user-defined name-value pairs that can contain text, numbers, dates, or boolean values.

This article covers two core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Read Standard and Custom Document Properties

Reading document properties is the first step in understanding an Excel file's metadata. Through the DocumentProperties and CustomDocumentProperties collections, you can easily access all property information stored in the file. The steps are as follows:

  • Create a Workbook object and load an existing Excel file.
  • Retrieve the standard document properties collection via workbook.DocumentProperties.
  • Iterate through the DocumentProperties collection to read each property's name and value.
  • Retrieve the custom document properties collection via workbook.CustomDocumentProperties.
  • Iterate through the CustomDocumentProperties collection to read each custom property's name and value.
  • Output the retrieved property information to a text file.

Below is a complete code example demonstrating how to read Excel document properties in React:

function App() {
  const readDocumentProperties = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });

    // Get standard document properties
    let properties1 = workbook.DocumentProperties;
    let sb = [];
    sb.push("Excel Properties:");
    for (let i = 0; i < properties1.Count; i++) {
      let name = properties1.get(i).Name;
      let obj = properties1.get(i).Value;
      let t = properties1.get(i).PropertyType;
      let value = null;
      if (t === xlsModule.PropertyType.Double) {
        value = xlsModule.Double.Convert(obj).Value;
      } else if (t === xlsModule.PropertyType.DateTime) {
        // Convert OADate to JavaScript Date and format as date string
        let oaDate = xlsModule.DateTime.Convert(obj).Value;
        let jsDate = new Date((oaDate - 25569) * 86400 * 1000);
        value = jsDate.toLocaleDateString();
      } else if (t === xlsModule.PropertyType.Bool) {
        value = xlsModule.Boolean.Convert(obj).Value;
      } else if (
        t === xlsModule.PropertyType.Int ||
        t === xlsModule.PropertyType.Int32
      ) {
        value = xlsModule.Int32.Convert(obj).Value;
      } else {
        value = xlsModule.String.Convert(obj).Value;
      }
      sb.push(name + ": " + String(value));
    }
    sb.push("");

    // Get custom document properties
    let properties2 = workbook.CustomDocumentProperties;
    sb.push("Custom Properties:");
    for (let i = 0; i < properties2.Count; i++) {
      let name = properties2.get(i).Name;
      let t = properties2.get(i).PropertyType;
      let obj = properties2.get(i).Value;
      let value = null;
      if (t === xlsModule.PropertyType.Double) {
        value = xlsModule.Double.Convert(obj).Value;
      } else if (t === xlsModule.PropertyType.DateTime) {
        // Convert OADate to JavaScript Date and format as date string
        let oaDate = xlsModule.DateTime.Convert(obj).Value;
        let jsDate = new Date((oaDate - 25569) * 86400 * 1000);
        value = jsDate.toLocaleDateString();
      } else if (t === xlsModule.PropertyType.Bool) {
        value = xlsModule.Boolean.Convert(obj).Value;
      } else if (
        t === xlsModule.PropertyType.Int ||
        t === xlsModule.PropertyType.Int32
      ) {
        value = xlsModule.Int32.Convert(obj).Value;
      } else {
        value = xlsModule.String.Convert(obj).Value;
      }
      sb.push(name + ": " + String(value));
    }

    // Save the property information to a text file
    const outputFileName = 'DocumentProperties.txt';
    window.dotnetRuntime.Module.FS.writeFile(outputFileName, sb.join("\n"));
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'text/plain' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Read Excel Document Properties</h1>
      <button onClick={readDocumentProperties}>
        Generate
      </button>
    </div>
  );
}

export default App;

Document properties read with Spire.XLS for JavaScript

Document properties read with Spire.XLS for JavaScript


Delete Standard and Custom Document Properties

In some scenarios, you may need to clear sensitive or outdated metadata from Excel files. Spire.XLS for JavaScript allows you to delete both standard and custom document properties through straightforward API calls. The steps are as follows:

  • Create a Workbook object and load an existing Excel file.
  • Retrieve the standard document properties collection via workbook.DocumentProperties.
  • Clear standard properties by setting their values to empty strings.
  • Retrieve the custom document properties collection via workbook.CustomDocumentProperties.
  • Iterate through the collection and use the Remove() method to delete each custom property.
  • Save the modified workbook to a new Excel file.

Below is a complete code example demonstrating how to delete Excel document properties in React:

function App() {
  const deleteDocumentProperties = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });

    // Get the standard document properties collection and clear their values
    let standardProperties = workbook.DocumentProperties;
    standardProperties.Title = "";
    standardProperties.Subject = "";
    standardProperties.Manager = "";
    standardProperties.Category = "";
    standardProperties.Keywords = "";
    standardProperties.Comments = "";
    standardProperties.Author = "";
    standardProperties.Company = "";

    // Get the custom document properties collection, iterate and remove all properties
    let customProperties = workbook.CustomDocumentProperties;
    for (let i = customProperties.Count - 1; i >= 0; i--) {
      customProperties.Remove(customProperties.get(i).Name);
    }

    // Save the workbook
    const outputFileName = 'DeleteProperties.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Delete Excel Document Properties</h1>
      <button onClick={deleteDocumentProperties}>
        Generate
      </button>
    </div>
  );
}

export default App;

Document properties deleted with Spire.XLS for JavaScript

Document properties deleted with Spire.XLS for JavaScript


FAQ

Why can't standard document properties be removed using Remove() like custom properties?

Cause: Standard document properties are part of the Excel file structure, each with a fixed definition position that cannot be removed from the collection.

Solution: Clear standard properties by setting their values to empty strings instead of removing the properties themselves:

standardProperties.Title = "";
standardProperties.Author = "";

Custom properties can be directly deleted using the Remove() method.

How to handle reading non-text property types such as dates, booleans, and numbers?

Cause: Using String.Convert() directly on date or boolean properties may produce results in an unexpected format.

Solution: Check the PropertyType to determine the type and use the appropriate conversion method:

if (t === xlsModule.PropertyType.DateTime) {
  let oaDate = xlsModule.DateTime.Convert(obj).Value;
  let jsDate = new Date((oaDate - 25569) * 86400 * 1000);
  value = jsDate.toLocaleDateString();
} else if (t === xlsModule.PropertyType.Bool) {
  value = xlsModule.Boolean.Convert(obj).Value;
}

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Copying data within Excel files while preserving formatting is a common requirement in web-based spreadsheet applications. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server required. It provides comprehensive APIs to copy rows, columns, and cell ranges while keeping the original styles, fonts, colors, and other formatting intact.

This article covers three core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Copy Rows in Excel

With Spire.XLS for JavaScript, you can copy rows within the same worksheet or across different worksheets while preserving all formatting, formulas, and styles. This is useful when you need to duplicate structured data such as headers, summary rows, or formatted templates. Through the CopyRangeOptions parameter, you can flexibly configure copy options such as copying all formats, conditional formatting, data validation, or only formula result values. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file.
  2. Get the source and destination worksheets via workbook.Worksheets.get().
  3. Get the row to copy via sheet.Rows[index].
  4. Use sheet.Copy() with the source row, destination worksheet, destination row index, and CopyRangeOptions.All to copy the row and its formatting.
  5. Copy the column widths from the source row cells to the corresponding destination row cells.
  6. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to copy rows in React:

function App() {
  const copyRows = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Fetch the Excel file and add it to the Virtual File System (VFS)
    let excelFileName = 'Copying.xls';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a new workbook and load an existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });

    // Get the source and destination worksheets
    let sheet1 = workbook.Worksheets.get(0);
    let sheet2 = workbook.Worksheets.get(1);

    // Get the row to copy
    let row = sheet1.Rows[0];

    // Copy the row to the destination worksheet with all formatting
    sheet1.Copy({ sourceRange: row, destRange: sheet2.Rows[0], copyOptions: xlsModule.CopyRangeOptions.All });

    // Copy the column widths from source row to destination row
    let columns = sheet1.Columns.length;
    for (let i = 0; i < columns; i++) {
      let columnWidth = row.Columns[i].ColumnWidth;
      sheet2.Rows[0].Columns[i].ColumnWidth = columnWidth;
    }

    // Save the workbook
    const outputFileName = 'CopyRows_out.xlsx';
    workbook.SaveToFile({ fileName: outputFileName, version: xlsModule.ExcelVersion.Version2010 });
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Copy Excel Rows</h1>
      <button onClick={copyRows}>
        Generate
      </button>
    </div>
  );
}

export default App;

Row copy result

Row copy result


Copy Columns in Excel

Copying columns is equally straightforward with Spire.XLS for JavaScript. You can duplicate a column within the same worksheet or copy it to another sheet, and all cell styles, number formats, and data will be preserved. Through the CopyRangeOptions parameter, you can flexibly configure which elements to copy. This is particularly helpful for reorganizing spreadsheet layouts or replicating data structures. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file.
  2. Get the source and destination worksheets.
  3. Get the column to copy via sheet.Columns[index].
  4. Use sheet.Copy() with the source column, destination worksheet, destination column index, and CopyRangeOptions.All to copy the column and its formatting.
  5. Copy the column widths and row heights from the source column cells to the corresponding destination column cells.
  6. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to copy columns in React:

function App() {
  const copyColumns = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Fetch the Excel file and add it to the Virtual File System (VFS)
    let excelFileName = 'Copying.xls';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a new workbook and load an existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });

    // Get the source and destination worksheets
    let sheet1 = workbook.Worksheets.get(0);
    let sheet2 = workbook.Worksheets.get(1);

    // Get the column to copy
    let column = sheet1.Columns[0];

    // Copy the column to the destination worksheet with all formatting
    sheet1.Copy({ sourceRange: column, destRange: sheet2.Columns[0], copyOptions: xlsModule.CopyRangeOptions.All });

    // Copy the column width and row heights from source column to destination column
    sheet2.Columns[0].ColumnWidth = column.ColumnWidth;
    let rows = column.Rows.length;
    for (let i = 0; i < rows; i++) {
      let rowHeight = column.Rows[i].RowHeight;
      sheet2.Columns[0].Rows[i].RowHeight = rowHeight;
    }

    // Save the workbook
    const outputFileName = 'CopyColumns_out.xlsx';
    workbook.SaveToFile({ fileName: outputFileName, version: xlsModule.ExcelVersion.Version2010 });
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Copy Excel Columns</h1>
      <button onClick={copyColumns}>
        Generate
      </button>
    </div>
  );
}

export default App;

Column copy result

Column copy result


Copy Cells in Excel

Beyond copying entire rows and columns, Spire.XLS for JavaScript also allows you to copy specific cell ranges from one location to another while preserving all formatting. The CellRange.Copy() method provides this capability with flexible options. This gives you fine-grained control over which cells to duplicate. You can copy a range of cells within the same worksheet or to a different worksheet. The steps are as follows:

  1. Create a Workbook object and load an existing Excel file.
  2. Get the source and destination worksheets.
  3. Get the source cell range and destination cell range via sheet.Range.get().
  4. Use sourceRange.Copy() with the destination range and CopyRangeOptions.All to copy the cell range with all formatting.
  5. Copy the column widths and row heights from the source range to the destination range.
  6. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to copy cells in React:

function App() {
  const copyCells = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Fetch the Excel file and add it to the Virtual File System (VFS)
    let excelFileName = 'Copying.xls';
    await window.spire.FetchFileToVFS(excelFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Create a new workbook and load an existing file
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: excelFileName });

    // Get the source and destination worksheets
    let sheet1 = workbook.Worksheets.get(0);
    let sheet2 = workbook.Worksheets.get(1);

    // Get the source cell range and destination cell range
    let range1 = sheet1.Range.get("A1:E7");
    let range2 = sheet2.Range.get("A1:E7");

    // Copy the source range to the destination range with all formatting
    range1.Copy({ destRange: range2, copyOptions: xlsModule.CopyRangeOptions.All });

    // Copy the row heights and column widths from source to destination
    for (let i = 0; i < range1.Rows.length; i++) {
      let row = range1.Rows[i];
      for (let j = 0; j < row.Columns.length; j++) {
        let column = row.Columns[j];
        range2.Rows[i].Columns[j].ColumnWidth = column.ColumnWidth;
        range2.Rows[i].RowHeight = row.RowHeight;
      }
    }

    // Save the workbook
    const outputFileName = 'CopyCells.xlsx';
    workbook.SaveToFile({ fileName: outputFileName, version: xlsModule.ExcelVersion.Version2010 });
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Copy Excel Cells</h1>
      <button onClick={copyCells}>
        Generate
      </button>
    </div>
  );
}

export default App;

Cell copy result

Cell copy result


FAQ

What happens if the target location already contains data

Cause: By default, the Copy() method overwrites existing data at the target location without merging or preserving the original content.

Solution: Choose an empty area as the destination range, or check whether the target range is empty before performing the copy. You can also back up the target data first, then execute the copy operation.

Can I copy only values without formulas

Cause: CopyRangeOptions.All copies formulas themselves, but sometimes you only need the calculated result values without preserving the formula logic.

Solution: Use the CopyRangeOptions.OnlyCopyFormulaValue option to copy only the calculated result values, not the formulas themselves:

sourceRange.Copy({ destRange: destRange, copyOptions: xlsModule.CopyRangeOptions.OnlyCopyFormulaValue });

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Configuring page setup is essential for preparing Excel documents for printing or PDF export. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server required. It provides comprehensive page setup capabilities through the PageSetup object, allowing you to control margins, orientation, paper size, print area, zoom scaling, and fit-to-page options.

The PageSetup object in Spire.XLS offers a rich set of properties for controlling how a worksheet is printed or displayed. Key properties include:

Property Description
TopMargin / BottomMargin / LeftMargin / RightMargin Sets the page margins
Orientation Sets the page orientation (Portrait or Landscape)
PaperSize Sets the paper size (A4, Letter, etc.)
PrintArea Specifies the cell range to print
Zoom Sets the worksheet zoom scaling percentage
FitToPagesTall / FitToPagesWide Scales the worksheet to fit a specified number of pages

This article covers six core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Adjust Excel Page Margins

Page margins define the blank space around the edges of a printed worksheet. The steps are as follows:

  • Create a Workbook object using new xlsModule.Workbook().
  • Get the default worksheet using the workbook.Worksheets.get(index) method.
  • Access the PageSetup object through sheet.PageSetup.
  • Set page margins using the TopMargin, BottomMargin, LeftMargin, and RightMargin properties.
  • Save the workbook to an Excel file using the workbook.SaveToFile() method.

Below is a complete code example demonstrating how to adjust page margins in React:

function App() {
  const adjustPageMargins = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a workbook and load the existing file
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });
    const sheet = workbook.Worksheets.get(0);

    // Get the PageSetup object
    const pageSetup = sheet.PageSetup;

    // Set the top, bottom, left, right, header, and footer margins
    pageSetup.TopMargin = 1;
    pageSetup.BottomMargin = 1;
    pageSetup.LeftMargin = 0.75;
    pageSetup.RightMargin = 0.75;

    // Save the workbook
    const outputFileName = 'AdjustMargins.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Adjust Page Margins</h1>
      <button onClick={adjustPageMargins}>
        Generate
      </button>
    </div>
  );
}

export default App;

Page margins adjusted with Spire.XLS for JavaScript

Page margins adjusted with Spire.XLS for JavaScript


Adjust Excel Page Orientation

Page orientation determines whether a worksheet is printed in portrait (vertical) or landscape (horizontal) layout. Landscape orientation is especially useful for wide tables with many columns. The steps are as follows:

  • Create a Workbook object using new xlsModule.Workbook().
  • Get the default worksheet using the workbook.Worksheets.get(index) method.
  • Access the PageSetup object through sheet.PageSetup.
  • Set the page orientation using the Orientation property.
  • Save the workbook to an Excel file using the workbook.SaveToFile() method.

Below is a complete code example demonstrating how to set the page orientation to landscape in React:

function App() {
  const setPageOrientation = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a workbook and load the existing file
    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });
    const sheet = workbook.Worksheets.get(0);

    // Set the page orientation to Landscape
    sheet.PageSetup.Orientation = xlsModule.PageOrientationType.Landscape;

    // Save the workbook
    const outputFileName = 'SetOrientation.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Set Page Orientation</h1>
      <button onClick={setPageOrientation}>
        Generate
      </button>
    </div>
  );
}

export default App;

Page orientation set to landscape with Spire.XLS for JavaScript

Page orientation set to landscape with Spire.XLS for JavaScript


Adjust Excel Paper Size

Different printers and regions use different standard paper sizes. Spire.XLS for JavaScript supports a wide range of paper sizes through the PaperSizeType enumeration, including A4, Letter, A3, and many more. The steps are as follows:

  • Create a Workbook object using new xlsModule.Workbook().
  • Get the default worksheet using the workbook.Worksheets.get(index) method.
  • Access the PageSetup object through sheet.PageSetup.
  • Set the paper size using the PaperSize property.
  • Save the workbook to an Excel file using the workbook.SaveToFile() method.

Below is a complete code example demonstrating how to set the paper size to A3 in React:

function App() {
  const setPaperSize = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a workbook and load the existing file
    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });
    const sheet = workbook.Worksheets.get(0);

    // Get the PageSetup object
    const pageSetup = sheet.PageSetup;

    // Set the paper size to A3
    pageSetup.PaperSize = xlsModule.PaperSizeType.PaperA3;

    // Save the workbook
    const outputFileName = 'SetPaperSize.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Set Paper Size</h1>
      <button onClick={setPaperSize}>
        Generate
      </button>
    </div>
  );
}

export default App;

Paper size set to A3 with Spire.XLS for JavaScript

Paper size set to A3 with Spire.XLS for JavaScript


Adjust Excel Print Area

The print area defines which portion of a worksheet will be printed. The steps are as follows:

  • Create a Workbook object using new xlsModule.Workbook().
  • Get the default worksheet using the workbook.Worksheets.get(index) method.
  • Populate sample data using the sheet.Range property.
  • Access the PageSetup object through sheet.PageSetup.
  • Set the print area using the PrintArea property.
  • Save the workbook to an Excel file using the workbook.SaveToFile() method.

Below is a complete code example demonstrating how to set the print area in React:

function App() {
  const setPrintArea = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a workbook and load the existing file
    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });
    const sheet = workbook.Worksheets.get(0);

    // Set the print area to A1:E3
    sheet.PageSetup.PrintArea = "A1:E3";

    // Save the workbook
    const outputFileName = 'SetPrintArea.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Set Print Area</h1>
      <button onClick={setPrintArea}>
        Generate
      </button>
    </div>
  );
}

export default App;

Print area set with Spire.XLS for JavaScript

Print area set with Spire.XLS for JavaScript


Adjust Excel Zoom Scale

The zoom scale controls the magnification level at which a worksheet is displayed on screen. The value ranges from 10 to 400, representing a percentage of normal size. The steps are as follows:

  • Create a Workbook object using new xlsModule.Workbook().
  • Get the default worksheet using the workbook.Worksheets.get(index) method.
  • Set the zoom scale using the Zoom property.
  • Save the workbook to an Excel file using the workbook.SaveToFile() method.

Below is a complete code example demonstrating how to set the zoom scale in React:

function App() {
  const setZoomScale = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a workbook and load the existing file
    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });
    const sheet = workbook.Worksheets.get(0);

    // Set the zoom scale to 85%
    const pageSetup = sheet.PageSetup;
    pageSetup.Zoom = 85;

    // Save the workbook
    const outputFileName = 'SetZoomScale.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Set Zoom Scale</h1>
      <button onClick={setZoomScale}>
        Generate
      </button>
    </div>
  );
}

export default App;

Zoom scale set to 85% with Spire.XLS for JavaScript

Zoom scale set to 85% with Spire.XLS for JavaScript


Fit Excel Table to 1 Page

When printing a large worksheet, the content may span multiple pages, making it difficult to read. The steps are as follows:

  • Create a Workbook object using new xlsModule.Workbook().
  • Get the default worksheet using the workbook.Worksheets.get(index) method.
  • Populate sample data using the sheet.Range property.
  • Access the PageSetup object through sheet.PageSetup.
  • Set the fit-to-page properties using the FitToPagesTall and FitToPagesWide properties.
  • Save the workbook to an Excel file using the workbook.SaveToFile() method.

Below is a complete code example demonstrating how to fit a worksheet to one page in React:

function App() {
  const fitToPage = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a workbook and load the existing file
    // Load the sample file into VFS
    await window.spire.FetchFileToVFS('Sample.xlsx', '', `${process.env.PUBLIC_URL}data/`);

    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: 'Sample.xlsx' });
    const sheet = workbook.Worksheets.get(0);

    // Fit the worksheet content to 1 page
    const pageSetup = sheet.PageSetup;
    pageSetup.FitToPagesTall = 1;
    pageSetup.FitToPagesWide = 1;

    // Save the workbook
    const outputFileName = 'FitToPage.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Fit Worksheet to 1 Page</h1>
      <button onClick={fitToPage}>
        Generate
      </button>
    </div>
  );
}

export default App;

Worksheet scaled to fit one page with Spire.XLS for JavaScript

Worksheet scaled to fit one page with Spire.XLS for JavaScript


FAQ

How to print gridlines or row/column headings

Cause: By default, gridlines and row/column headings are not printed, which can make the data harder to read on paper.

Solution: Use the IsPrintGridlines and IsPrintHeadings properties of the PageSetup object:

pageSetup.IsPrintGridlines = true;
pageSetup.IsPrintHeadings = true;

How to get the actual page dimensions

Cause: You may need to know the actual width and height of the current paper size to adjust content layout.

Solution: Retrieve the values using the PageWidth and PageHeight properties of the PageSetup object:

var pageWidth = pageSetup.PageWidth;
var pageHeight = pageSetup.PageHeight;

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Adding charts to Excel files is one of the most common data visualization requirements in web applications. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server required. It supports creating a wide variety of chart types, including column charts, pie charts, doughnut charts, line charts, scatter charts, and more.

This article covers three core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Create a Column Chart

Column charts are one of the most commonly used chart types for comparing values across categories. With Spire.XLS for JavaScript, you can create a clustered column chart by first populating a worksheet with data, then adding a chart object, setting the chart type to ColumnClustered, and configuring the chart title, axes, and data labels. The steps are as follows:

  1. Create a Workbook object and get the default worksheet.
  2. Populate the worksheet with category labels and numeric data.
  3. Add a chart to the worksheet using sheet.Charts.Add().
  4. Set the chart's DataRange to the data range and specify the chart type as ExcelChartType.ColumnClustered.
  5. Configure the chart position, title, axis titles, and legend.
  6. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to create a clustered column chart in React:

function App() {
  const createColumnChart = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a new workbook and get the default worksheet
    const workbook = new xlsModule.Workbook();
    const sheet = workbook.Worksheets.get(0);
    sheet.Name = "ClusteredColumn";

    // Populate chart data
    sheet.Range.get("A1").Value = "Country";
    sheet.Range.get("A2").Value = "Cuba";
    sheet.Range.get("A3").Value = "Mexico";
    sheet.Range.get("A4").Value = "France";
    sheet.Range.get("A5").Value = "German";

    sheet.Range.get("B1").Value = "Jun";
    sheet.Range.get("B2").NumberValue = 6000;
    sheet.Range.get("B3").NumberValue = 8000;
    sheet.Range.get("B4").NumberValue = 9000;
    sheet.Range.get("B5").NumberValue = 8500;

    sheet.Range.get("C1").Value = "Aug";
    sheet.Range.get("C2").NumberValue = 3000;
    sheet.Range.get("C3").NumberValue = 2000;
    sheet.Range.get("C4").NumberValue = 2300;
    sheet.Range.get("C5").NumberValue = 4200;

    // Add a chart and set its data range
    const chart = sheet.Charts.Add();
    chart.DataRange = sheet.Range.get("A1:C5");
    chart.SeriesDataFromRange = false;

    // Set the chart position
    chart.LeftColumn = 1;
    chart.TopRow = 6;
    chart.RightColumn = 11;
    chart.BottomRow = 29;

    // Set the chart type to clustered column
    chart.ChartType = xlsModule.ExcelChartType.ColumnClustered;

    // Configure chart title
    chart.ChartTitle = "Sales market by country";
    chart.ChartTitleArea.IsBold = true;
    chart.ChartTitleArea.Size = 12;

    // Configure axis titles
    chart.PrimaryCategoryAxis.Title = "Country";
    chart.PrimaryCategoryAxis.Font.IsBold = true;
    chart.PrimaryCategoryAxis.TitleArea.IsBold = true;

    chart.PrimaryValueAxis.Title = "Sales(in Dollars)";
    chart.PrimaryValueAxis.HasMajorGridLines = false;
    chart.PrimaryValueAxis.MinValue = 1000;
    chart.PrimaryValueAxis.TitleArea.IsBold = true;
    chart.PrimaryValueAxis.TitleArea.TextRotationAngle = 90;

    // Configure data labels: show numeric value on each data point
    for (let i = 0; i < chart.Series.Length; i++) {
      let cs = chart.Series.get(i);
      cs.Format.Options.IsVaryColor = true;
      cs.DataPoints.DefaultDataPoint.DataLabels.HasValue = true; // Show value labels
    }

    // Set legend position
    chart.Legend.Position = xlsModule.LegendPositionType.Top;

    // Save the workbook
    const outputFileName = 'ClusteredColumn.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Create Clustered Column Chart</h1>
      <button onClick={createColumnChart}>
        Generate
      </button>
    </div>
  );
}

export default App;

Clustered column chart created with Spire.XLS for JavaScript

Clustered column chart created with Spire.XLS for JavaScript


Create a Pie Chart

Pie charts are ideal for displaying the proportional distribution of data across categories. With Spire.XLS for JavaScript, you can create a pie chart by specifying the chart type as Pie when adding the chart, then binding category labels and data values. The steps are as follows:

  1. Create a Workbook object and get the default worksheet.
  2. Populate the worksheet with category labels and numeric values.
  3. Add a chart with ExcelChartType.Pie using sheet.Charts.Add().
  4. Set the chart data range and bind category labels and values.
  5. Configure the chart position, title, and data labels.
  6. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to create a pie chart in React:

function App() {
  const createPieChart = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a new workbook and get the default worksheet
    const workbook = new xlsModule.Workbook();
    let sheet = workbook.Worksheets.get(0);
    sheet.Name = "Pie Chart";

    // Populate chart data
    sheet.Range.get("A1").Value = "Year";
    sheet.Range.get("A2").Value = "2002";
    sheet.Range.get("A3").Value = "2003";
    sheet.Range.get("A4").Value = "2004";
    sheet.Range.get("A5").Value = "2005";

    sheet.Range.get("B1").Value = "Sales";
    sheet.Range.get("B2").NumberValue = 4000;
    sheet.Range.get("B3").NumberValue = 6000;
    sheet.Range.get("B4").NumberValue = 7000;
    sheet.Range.get("B5").NumberValue = 8500;

    // Add a pie chart
    let chart = sheet.Charts.Add({ chartType: xlsModule.ExcelChartType.Pie });
    chart.DataRange = sheet.Range.get("B2:B5");
    chart.SeriesDataFromRange = false;

    // Set the chart position
    chart.LeftColumn = 1;
    chart.TopRow = 6;
    chart.RightColumn = 9;
    chart.BottomRow = 25;

    // Configure chart title
    chart.ChartTitle = "Sales by year";
    chart.ChartTitleArea.IsBold = true;
    chart.ChartTitleArea.Size = 12;

    // Bind category labels and values
    let cs = chart.Series.get(0);
    cs.CategoryLabels = sheet.Range.get("A2:A5");
    cs.Values = sheet.Range.get("B2:B5");
    cs.DataPoints.DefaultDataPoint.DataLabels.HasValue = true; // Show value labels

    chart.PlotArea.Fill.Visible = false;

    // Save the workbook
    const outputFileName = 'Pie.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Create Pie Chart</h1>
      <button onClick={createPieChart}>
        Generate
      </button>
    </div>
  );
}

export default App;

Pie chart created with Spire.XLS for JavaScript

Pie chart created with Spire.XLS for JavaScript


Create a Doughnut Chart

A doughnut chart is similar to a pie chart but with a hollow center, which can display multiple data series. With Spire.XLS for JavaScript, you can create a doughnut chart by setting the chart type to Doughnut and configuring percentage data labels. The steps are as follows:

  1. Create a Workbook object and get the default worksheet.
  2. Populate the worksheet with category labels and numeric values.
  3. Add a chart and set its ChartType to ExcelChartType.Doughnut.
  4. Configure the chart position, title, and percentage data labels.
  5. Save the workbook to an Excel file using SaveToFile().

Below is a complete code example demonstrating how to create a doughnut chart in React:

function App() {
  const createDoughnutChart = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Create a new workbook and get the default worksheet
    const workbook = new xlsModule.Workbook();
    let sheet = workbook.Worksheets.get(0);

    // Populate chart data
    sheet.Range.get("A1").Value = "Country";
    sheet.Range.get("A1").Style.Font.IsBold = true;
    sheet.Range.get("A2").Value = "Cuba";
    sheet.Range.get("A3").Value = "Mexico";
    sheet.Range.get("A4").Value = "France";
    sheet.Range.get("A5").Value = "German";
    sheet.Range.get("B1").Value = "Sales";
    sheet.Range.get("B1").Style.Font.IsBold = true;
    sheet.Range.get("B2").NumberValue = 6000;
    sheet.Range.get("B3").NumberValue = 8000;
    sheet.Range.get("B4").NumberValue = 9000;
    sheet.Range.get("B5").NumberValue = 8500;

    // Add a doughnut chart
    let chart = sheet.Charts.Add();
    chart.ChartType = xlsModule.ExcelChartType.Doughnut;
    chart.DataRange = sheet.Range.get("A1:B5");
    chart.SeriesDataFromRange = false;

    // Set the chart position
    chart.LeftColumn = 4;
    chart.TopRow = 2;
    chart.RightColumn = 12;
    chart.BottomRow = 22;

    // Configure chart title
    chart.ChartTitle = "Market share by country";
    chart.ChartTitleArea.IsBold = true;
    chart.ChartTitleArea.Size = 12;

    // Show percentage data labels
    for (let i = 0; i < chart.Series.Count; i++) {
      chart.Series.get(i).DataPoints.DefaultDataPoint.DataLabels.HasPercentage = true;
    }

    // Set legend position
    chart.Legend.Position = xlsModule.LegendPositionType.Top;

    // Save the workbook
    const outputFileName = 'CreateDoughnutChart.xlsx';
    workbook.SaveToFile(outputFileName);
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Create Doughnut Chart</h1>
      <button onClick={createDoughnutChart}>
        Generate
      </button>
    </div>
  );
}

export default App;

Doughnut chart created with Spire.XLS for JavaScript

Doughnut chart created with Spire.XLS for JavaScript


Chart Type Reference

The examples above covered column charts, pie charts, and doughnut charts. In addition, Spire.XLS supports all standard Excel chart types, which are defined in the Spire.Xls.ExcelChartType enumeration. The complete list of 81 chart types is as follows:

Chart Type Description
1. ColumnClustered Represents Clustered Column Chart
2. ColumnStacked Represents Stacked Column Chart
3. Column100PercentStacked Represents 100% Stacked Column Chart
4. Column3DClustered Represents 3D Clustered Column Chart
5. Column3DStacked Represents 3D Stacked Column Chart
6. Column3D100PercentStacked Represents 3D 100% Stacked Column Chart
7. Column3D Represents 3D Column Chart
8. BarClustered Represents Clustered Bar Chart
9. BarStacked Represents Stacked Bar Chart
10. Bar100PercentStacked Represents 100% Stacked Bar Chart
11. Bar3DClustered Represents 3D Clustered Bar Chart
12. Bar3DStacked Represents 3D Stacked Bar Chart
13. Bar3D100PercentStacked Represents 100% 3D Stacked Bar Chart
14. Line Represents Line Chart
15. LineStacked Represents Stacked Line Chart
16. Line100PercentStacked Represents 100% Stacked Line Chart
17. LineMarkers Represents Markers Line Chart
18. LineMarkersStacked Represents Stacked Markers Line Chart
19. LineMarkers100PercentStacked Represents 100% Stacked Markers Line Chart
20. Line3D Represents 3D Line Chart
21. Pie Represents Pie Chart
22. Pie3D = 21 Represents 3D Pie Chart
23. PieOfPie Represents Pie of Pie chart
24. PieExploded Represents Exploded Pie Chart
25. Pie3DExploded Represents 3D Exploded Pie Chart
26. PieBar Represents Bar Pie Chart
27. ScatterMarkers Represents Markers Scatter Chart
28. ScatterSmoothedLineMarkers Represents ScatterSmoothedLineMarkers Chart
29. ScatterSmoothedLine Represents ScatterSmoothedLine Chart
30. ScatterLineMarkers Represents ScatterLineMarkers Chart
31. ScatterLine Represents ScatterLine Chart
32. Area Represents Area Chart
33. AreaStacked Represents AreaStacked Chart
34. Area100PercentStacked Represents Area100PercentStacked Chart
35. Area3D Represents Area3D Chart
36. Area3DStacked Represents Area3DStacked Chart
37. Area3D100PercentStacked Represents Area3D100PercentStacked Chart
38. Doughnut Represents Doughnut Chart
39. DoughnutExploded Represents DoughnutExploded Chart
40. Radar Represents Radar Chart
41. RadarMarkers Represents RadarMarkers Chart
42. RadarFilled Represents RadarFilled Chart
43. Surface3D Represents Surface3D Chart
44. Surface3DNoColor Represents Surface3DNoColor Chart
45. SurfaceContour Represents SurfaceContour Chart
46. SurfaceContourNoColor Represents SurfaceContourNoColor Chart
47. Bubble Represents Bubble Chart
48. Bubble3D Represents Bubble3D Chart
49. StockHighLowClose Represents StockHighLowClose Chart
50. StockOpenHighLowClose Represents StockOpenHighLowClose Chart
51. StockVolumeHighLowClose Represents StockVolumeHighLowClose Chart
52. StockVolumeOpenHighLowClose Represents StockVolumeOpenHighLowClose Chart
53. CylinderClustered Represents CylinderClustered Chart
54. CylinderStacked Represents CylinderStacked Chart
55. Cylinder100PercentStacked Represents Cylinder100PercentStacked Chart
56. CylinderBarClustered Represents CylinderBarClustered Chart
57. CylinderBarStacked Represents CylinderBarStacked Chart
58. CylinderBar100PercentStacked Represents CylinderBar100PercentStacked Chart
59. Cylinder3DClustered Represents Cylinder3DClustered Chart
60. ConeClustered Represents ConeClustered Chart
61. ConeStacked Represents ConeStacked Chart
62. Cone100PercentStacked Represents Cone100PercentStacked Chart
63. ConeBarClustered Represents ConeBarClustered Chart
64. ConeBarStacked Represents ConeBarStacked Chart
65. ConeBar100PercentStacked Represents ConeBar100PercentStacked Chart
66. Cone3DClustered Represents Cone3DClustered Chart
67. PyramidClustered Represents PyramidClustered Chart
68. PyramidStacked Represents PyramidStacked Chart
69. Pyramid100PercentStacked Represents Pyramid100PercentStacked Chart
70. PyramidBarClustered Represents PyramidBarClustered Chart
71. PyramidBarStacked Represents PyramidBarStacked Chart
72. PyramidBar100PercentStacked Represents PyramidBar100PercentStacked Chart
73. Pyramid3DClustered Represents Pyramid3DClustered Chart
74. CombinationChart Represents Combination Chart
75. Funnel Represents Funnel Chart
76. WaterFall Represents Waterfall Chart
77. BoxAndWhisker Represents Box and Whisker Chart
78. Histogram Represents Histogram Chart
79. Pareto Represents Pareto Chart
80. TreeMap Represents Tree Map Chart
81. SunBurst Represents Sunburst Chart

FAQ

How to show values or percentages on pie/doughnut chart labels

Solution: Choose the appropriate label property based on your needs:

// Show value labels
cs.DataPoints.DefaultDataPoint.DataLabels.HasValue = true; // Show value labels
// Or show percentage labels
cs.DataPoints.DefaultDataPoint.DataLabels.HasPercentage = true;

Legend in the generated Excel file is truncated or not fully displayed

Cause: The chart area is too small to accommodate all legend items, or the legend position setting causes overlap with the chart data area.

Solution: Increase the vertical range of the chart or adjust the legend position:

// Increase chart height
chart.BottomRow = 35;
// Or adjust legend position
chart.Legend.Position = xlsModule.LegendPositionType.Bottom;

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

Digital signatures ensure the authenticity of an Excel file's source and verify that its content has not been tampered with. Spire.XLS for JavaScript runs entirely in the browser via WebAssembly, using a virtual file system (VFS) to manage input and output files — no backend server required.

This article covers two core features:

For installation and project setup, refer to Integrating Spire.XLS for JavaScript in a React Project. The examples below assume Spire.XLS is installed and the WebAssembly module is initialized.


Detect Whether an Excel File Is Signed

Before processing a signed Excel file, checking its signature status can prevent unintended operations. Spire.XLS provides the IsDigitallySigned property to determine whether a workbook contains digital signatures. The core process consists of three stages: first, load the font files and the target Excel file into the WASM virtual file system via FetchFileToVFS; then, instantiate a Workbook and load the file; finally, retrieve the signature status through the IsDigitallySigned property.

function App() {
  const detectDigitalSignature = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load fonts and Excel file into VFS
    await window.spire.FetchFileToVFS('arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/font/`);
    const inputFileName = 'Sample.xlsx';
    await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Load the workbook
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: inputFileName });

    // Detect if the workbook contains digital signatures
    const isSigned = workbook.IsDigitallySigned;

    // Dispose of the workbook object to release resources
    workbook.Dispose();

    // Show the detection result
    alert(isSigned ? 'The file is signed' : 'The file is not signed');
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Detect Digital Signature</h1>
      <button onClick={detectDigitalSignature}>
        Detect
      </button>
    </div>
  );
}

export default App;

Detection result dialog showing whether the file is signed

Detection result dialog showing whether the file is signed


Remove Digital Signatures from an Excel File

In cases where signature information needs to be updated, certificates replaced, or digital authentication canceled, the existing digital signatures must be removed from the Excel file. Using Spire.XLS, the core process consists of three stages: first, load the font files and the signed Excel file into the WASM virtual file system via FetchFileToVFS; then, instantiate a Workbook and load the file, calling RemoveAllDigitalSignatures to remove all digital signatures from the workbook at once; finally, save the workbook file with signatures removed via SaveToFile.

function App() {
  const removeDigitalSignatures = async () => {
    // Get the Spire.XLS WASM module
    const xlsModule = window.wasmModule?.spirexls;

    // Check if the module is ready
    if (!xlsModule) {
      alert('Spire.Xls is not ready yet');
      return;
    }

    // Load fonts and Excel file into VFS
    await window.spire.FetchFileToVFS('arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/font/`);
    const inputFileName = 'Sample.xlsx';
    await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}data/`);

    // Load the signed workbook
    const workbook = new xlsModule.Workbook();
    workbook.LoadFromFile({ fileName: inputFileName });

    // Remove all digital signatures
    workbook.RemoveAllDigitalSignatures();

    // Save the workbook without signatures
    const outputFileName = 'SignatureRemoved.xlsx';
    workbook.SaveToFile({ fileName: outputFileName, version: xlsModule.ExcelVersion.Version2010 });

    // Dispose of the workbook object to release resources
    workbook.Dispose();

    // Read the file from VFS and trigger download
    const fileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
    const blob = new Blob([fileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = outputFileName;
    a.click();
    URL.revokeObjectURL(url);
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Remove Digital Signatures</h1>
      <button onClick={removeDigitalSignatures}>
        Remove Signatures
      </button>
    </div>
  );
}

export default App;

Output document after removing digital signatures

Output document after removing digital signatures


FAQ

Can I detect a signature on a specific worksheet instead of the entire workbook?

Cause: Digital signatures are applied to the entire workbook, not individual worksheets.

Solution: Digital signatures operate at the workbook level. It is not possible to detect or remove signatures on a single worksheet. Both IsDigitallySigned and RemoveAllDigitalSignatures are workbook-level methods.

How do I batch detect or remove signatures from multiple Excel files?

Cause: Real-world projects often involve processing large numbers of files, making manual processing inefficient.

Solution: Use a loop to process files in batch:

const files = ['report1.xlsx', 'report2.xlsx', 'report3.xlsx'];
for (const file of files) {
  await window.spire.FetchFileToVFS(file, '', dataPath);
  const wb = new xlsModule.Workbook();
  wb.LoadFromFile({ fileName: file });
  if (wb.IsDigitallySigned) {
    wb.RemoveAllDigitalSignatures();
  }
  wb.SaveToFile({ fileName: `unsigned_${file}`, version: xlsModule.ExcelVersion.Version2016 });
  wb.Dispose();
}

Get a Free License

Spire.XLS for JavaScript offers a 30-day full-featured free trial license with no functional limitations. Apply here to evaluate before purchasing.

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