Converting between Excel and HTML formats is a common task for developers working on data visualization, reporting, or web-based applications. Excel files are often used to store, organize, and analyze structured data, while HTML is widely used to display information on the web. Converting between these two formats allows seamless integration between back-end data processing and front-end data presentation. In this article, we will demonstrate how to convert Excel files to HTML format and HTML files to Excel format in React using Spire.XLS for JavaScript.
Install Spire.XLS for JavaScript
To get started with converting Excel to PDF in a React application, you can either download Spire.XLS for JavaScript from our website or install it via npm with the following command:
npm i spire.office
The downloaded product package has been integrated Spire.Doc for JavaScript，Spire.XLS for JavaScript，Spire.PDF for JavaScript，Spire.Presentation for JavaScript. To use the functionality of Spire.XLS for JavaScript, you need to copy the corresponding files (spire.xls.js, Spire.Xls.Wasm.zip, spire.common.js, Spire.Common.Wasm.zip, and _framework) to the project's "public" folder. At the same time, in order to ensure text rendering, the related font files can be added with custom paths. In the following example, the font addition path is: public\static\font.
For more details, refer to the documentation: How to Integrate Spire.XLS for JavaScript in a React Project
Convert Excel to HTML in React
Spire.XLS for JavaScript provides the Worksheet.SaveToHtml() function, which enables you to save a specific worksheet in an Excel file as an HTML file. The key steps for converting an Excel worksheet to HTML using Spire.XLS for JavaScript are as follows.
- Create a Workbook object using the new wasmModule.Workbook() function.
- Load the Excel file using the Workbook.LoadFromFile() function.
- Get a specific worksheet using the Workbook.Worksheets.get(index) function.
- Create an HTMLOptions object using the new wasmModule.HTMLOptions() function.
- Set the HTMLOptions.ImageEmbedded property as "true" to embed images in the converted HTML file.
- Save the worksheet as an HTML file using the Worksheet.SaveToHtml() function.
- JavaScript
import React, { useState, useEffect } from 'react';
function App() {
const [wasmModule, setWasmModule] = useState(null);
// Load Spire.XLS
useEffect(() => {
(async () => {
try {
const publicUrl = process.env.PUBLIC_URL || '';
const spireModule = await import(/* webpackIgnore: true */ `${publicUrl}/spire.xls.js`);
const rawModule = spireModule.default || spireModule;
window.wasmModule = typeof rawModule === 'function'
? await rawModule({ locateFile: p => p.endsWith('.wasm') ? `${publicUrl}/${p}` : p })
: rawModule;
setWasmModule(window.wasmModule);
} catch (error) {
console.error('Failed to load spire.xls.js WASM module:', error);
}
})();
}, []);
// Function to convert an Excel worksheet to HTML
const ExcelToHTML = async () => {
const wasmModule = window.wasmModule.spirexls;
if (wasmModule) {
// Load font into Virtual File System (VFS)
await window.spire.FetchFileToVFS('Arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/static/font/`);
// Load input file into Virtual File System (VFS)
const inputFileName = 'sample.xlsx';
await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/static/data/`);
// Create a new workbook
const workbook = new wasmModule.Workbook();
// Load an existing Excel document
workbook.LoadFromFile({fileName: inputFileName});
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Create an HTMLOptions object
let options = new wasmModule.HTMLOptions();
// Embed images in the converted HTML file
options.ImageEmbedded = true;
// Specify the output HTML file path
const outputFileName = 'ToHtml.html';
// Save the worksheet to HTML with the images embedded
sheet.SaveToHtml({fileName:outputFileName, saveOption:options});
// Read the saved file and convert to Blob object
const modifiedFileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'text/html' });
// Create a URL for the Blob and initiate download
const url = URL.createObjectURL(modifiedFile);
const a = document.createElement('a');
a.href = url;
a.download = outputFileName;
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(url);
// Clean up resources used by the workbook
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Convert an Excel Worksheet to HTML Using JavaScript in React</h1>
<button onClick={ExcelToHTML} disabled={!wasmModule}>
Convert
</button>
</div>
);
}
export default App;
Run the code to launch the React app at localhost:3000. Once it's running, click on the "Convert" button to convert the specified Excel worksheet to HTML format:
The below screenshot shows the input Excel worksheet and the converted HTML file:
Convert HTML to Excel in React
Spire.XLS for JavaScript offers the Workbook.LoadFromHtml() function for loading an HTML file. Once the HTML file is loaded, you can save it as an Excel file using the Workbook.SaveToFile() function. The key steps are as follows.
- Create a Workbook object using the new wasmModule.Workbook() function.
- Load the HTML file using the Workbook.LoadFromHtml() function.
- Save the HTML file to an Excel file using the Workbook.SaveToFile() function.
- JavaScript
import React, { useState, useEffect } from 'react';
function App() {
const [wasmModule, setWasmModule] = useState(null);
// Load Spire.XLS
useEffect(() => {
(async () => {
try {
const publicUrl = process.env.PUBLIC_URL || '';
const spireModule = await import(/* webpackIgnore: true */ `${publicUrl}/spire.xls.js`);
const rawModule = spireModule.default || spireModule;
window.wasmModule = typeof rawModule === 'function'
? await rawModule({ locateFile: p => p.endsWith('.wasm') ? `${publicUrl}/${p}` : p })
: rawModule;
setWasmModule(window.wasmModule);
} catch (error) {
console.error('Failed to load spire.xls.js WASM module:', error);
}
})();
}, []);
// Function to convert an HTML to Excel
const HTMLToExcel = async () => {
const wasmModule = window.wasmModule.spirexls;
if (wasmModule) {
// Load font into Virtual File System (VFS)
await window.spire.FetchFileToVFS('Arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/static/font/`);
// Load input file into Virtual File System (VFS)
const inputFileName = 'in.html';
await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/static/data/`);
// Create a new workbook
const workbook = new wasmModule.Workbook();
// Load an existing HTML file
workbook.LoadFromHtml({ fileName: inputFileName });
// Specify the output Excel file path
const outputFileName = 'ToExcel.xlsx';
// Save the HTML file to Excel format
workbook.SaveToFile({ fileName: outputFileName, version: wasmModule.ExcelVersion.Version2013 });
// Read the saved file and convert to Blob object
const modifiedFileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type:'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
// Create a URL for the Blob and initiate download
const url = URL.createObjectURL(modifiedFile);
const a = document.createElement('a');
a.href = url;
a.download = outputFileName;
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(url);
// Clean up resources used by the workbook
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Convert an HTML File to Excel Using JavaScript in React</h1>
<button onClick={HTMLToExcel} disabled={!wasmModule}>
Convert
</button>
</div>
);
}
export default App;
Get a Free License
To fully experience the capabilities of Spire.XLS for JavaScript without any evaluation limitations, you can request a free 30-day trial license.
