Convert RTF to PDF and HTML with JavaScript in React

RTF files are versatile, containing text, images, and formatting information. Converting these files into PDF and HTML ensures that they are accessible and display consistently across various devices and browsers. Whether you're building a document viewer or integrating document management features into your application, mastering RTF conversion is a valuable skill.

In this article, you will learn how to convert RTF to PDF and RTF to HTML in React using Spire.Doc for JavaScript.

Install Spire.Doc for JavaScript

To get started with converting RTF to PDF and HTML in a React application, you can either download Spire.Doc for JavaScript from our website or install it via npm with the following command:

npm i spire.doc

After that, copy the "Spire.Doc.Base.js" and "Spire.Doc.Base.wasm" files to the public folder of your project. Additionally, include the required font files to ensure accurate and consistent text rendering.

For more details, refer to the documentation: How to Integrate Spire.Doc for JavaScript in a React Project

Convert RTF to PDF with JavaScript

With Spire.Doc for JavaScript, converting RTF files to PDF is straightforward. Utilize the Document.LoadFromFile() method to load the RTF file, preserving its formatting. Then, save it as a PDF using the Document.SaveToFile() method. This process ensures high-quality output, making file format conversion easy and efficient.

Here are the steps to convert RTF to PDF in React using Spire.Doc for JavaScript:

  • Load the font files used in the RTF document into the virtual file system (VFS).
  • Create a new Document object using the wasmModule.Document.Create() method.
  • Load the input RTF file using the Document.LoadFromFile() method.
  • Save the document as a PDF file using the Document.SaveToFile() method.
  • Generate a Blob from the PDF file, create a download link, and trigger the download.
  • JavaScript
import React, { useState, useEffect } from 'react';

function App() {

  // State to hold the loaded WASM module
  const [wasmModule, setWasmModule] = useState(null);

  // useEffect hook to load the WASM module when the component mounts
  useEffect(() => {
    const loadWasm = async () => {
      try {

        // Access the Module and spiredoc from the global window object
        const { Module, spiredoc } = window;

        // Set the wasmModule state when the runtime is initialized
        Module.onRuntimeInitialized = () => {
          setWasmModule(spiredoc);
        };
      } catch (err) {

        // Log any errors that occur during loading
        console.error('Failed to load WASM module:', err);
      }
    };

    // Create a script element to load the WASM JavaScript file
    const script = document.createElement('script');
    script.src = `${process.env.PUBLIC_URL}/Spire.Doc.Base.js`;
    script.onload = loadWasm;

    // Append the script to the document body
    document.body.appendChild(script);

    // Cleanup function to remove the script when the component unmounts
    return () => {
      document.body.removeChild(script);
    };
  }, []); 

  // Function to convert RTF to PDF
  const convertRtfToPdf = async () => {
    if (wasmModule) {

      // Load the font files into the virtual file system (VFS)
      await wasmModule.FetchFileToVFS('times.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      await wasmModule.FetchFileToVFS('timesbd.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      await wasmModule.FetchFileToVFS('timesbi.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      await wasmModule.FetchFileToVFS('timesi.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      
      // Specify the input file path
      const inputFileName = 'input.rtf'; 
   
      // Create a new document
      const doc= wasmModule.Document.Create();

      // Fetch the input file and add it to the VFS
      await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
      
      // Load the RTF file
      doc.LoadFromFile(inputFileName);

      // Define the output file name
      const outputFileName = "RtfToPdf.pdf";

      // Save the document to the specified path
      doc.SaveToFile({fileName: outputFileName, fileFormat: wasmModule.FileFormat.PDF});
 
      // Read the generated PDF file from VFS
      const modifiedFileArray = wasmModule.FS.readFile(outputFileName);

      // Create a Blob object from the PDF file
      const modifiedFile = new Blob([modifiedFileArray], { type: 'application/pdf'});

      // Create a URL for the Blob
      const url = URL.createObjectURL(modifiedFile);

      // Create an anchor element to trigger the download
      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
      doc.Dispose();
    }
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Convert RTF to PDF in React</h1>
      <button onClick={convertRtfToPdf} disabled={!wasmModule}>
        Convert
      </button>
    </div>
  );
}

export default App;

Run the code to launch the React app at localhost:3000. Click "Convert," and a "Save As" window will appear, prompting you to save the output file in your chosen folder.

React app runs at localhost:3000

Below is a screenshot of the generated PDF document:

Convert RTF to PDF in React

Convert RTF to HTML with JavaScript

When converting RTF to HTML, it's crucial to decide whether to embed image files and CSS stylesheets as internal resources, as these elements significantly impact the HTML file's display.

With Spire.Doc for JavaScript, you can easily configure these settings using the Document.HtmlExportOptions.CssStyleSheetType and Document.HtmlExportOptions.ImageEmbedded properties.

Here are the steps to convert RTF to HTML with embedded images and CSS stylesheets using Spire.Doc for JavaScript:

  • Load the font files used in the RTF document into the virtual file system (VFS).
  • Create a new Document object using the wasmModule.Document.Create() method.
  • Load the input RTF file using the Document.LoadFromFile() method.
  • Embed CSS stylesheet in the HTML file by setting the Document.HtmlExportOptions.CssStyleSheetType as Internal.
  • Embed image files in the HTML file by setting the Document.HtmlExportOptions.ImageEmbedded to true.
  • Save the document as an HTML file using the Document.SaveToFile() method.
  • Generate a Blob from the PDF file, create a download link, and trigger the download.
  • JavaScript
import React, { useState, useEffect } from 'react';

function App() {

  // State to hold the loaded WASM module
  const [wasmModule, setWasmModule] = useState(null);

  // useEffect hook to load the WASM module when the component mounts
  useEffect(() => {
    const loadWasm = async () => {
      try {

        // Access the Module and spiredoc from the global window object
        const { Module, spiredoc } = window;

        // Set the wasmModule state when the runtime is initialized
        Module.onRuntimeInitialized = () => {
          setWasmModule(spiredoc);
        };
      } catch (err) {

        // Log any errors that occur during loading
        console.error('Failed to load WASM module:', err);
      }
    };

    // Create a script element to load the WASM JavaScript file
    const script = document.createElement('script');
    script.src = `${process.env.PUBLIC_URL}/Spire.Doc.Base.js`;
    script.onload = loadWasm;

    // Append the script to the document body
    document.body.appendChild(script);

    // Cleanup function to remove the script when the component unmounts
    return () => {
      document.body.removeChild(script);
    };
  }, []); 

  // Function to convert RTF to HTML
  const convertRtfToHtml = async () => {
    if (wasmModule) {

      // Load the font files into the virtual file system (VFS)
      await wasmModule.FetchFileToVFS('times.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      await wasmModule.FetchFileToVFS('timesbd.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      await wasmModule.FetchFileToVFS('timesbi.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
      await wasmModule.FetchFileToVFS('timesi.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);

      // Specify the input file path
      const inputFileName = 'input.rtf'; 
   
      // Create a new document
      const doc= wasmModule.Document.Create();

      // Fetch the input file and add it to the VFS
      await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
      
      // Load the RTF file
      doc.LoadFromFile(inputFileName);

      // Embed CSS file in the HTML file      
      doc.HtmlExportOptions.CssStyleSheetType = wasmModule.CssStyleSheetType.Internal;     

      // Embed images in the HTML file      
      doc.HtmlExportOptions.ImageEmbedded = true;

      // Define the output file name
      const outputFileName = "RtfToHtml.html";

      // Save the document to the specified path
      doc.SaveToFile({fileName: outputFileName, fileFormat: wasmModule.FileFormat.Html});
 
      // Read the generated HTML file from VFS
      const modifiedFileArray = wasmModule.FS.readFile(outputFileName);

      // Create a Blob object from the HTML file
      const modifiedFile = new Blob([modifiedFileArray], { type: 'text/html'});

      // Create a URL for the Blob
      const url = URL.createObjectURL(modifiedFile);

      // Create an anchor element to trigger the download
      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
      doc.Dispose();
    }
  };

  return (
    <div style={{ textAlign: 'center', height: '300px' }}>
      <h1>Convert RTF to HTML in React</h1>
      <button onClick={convertRtfToHtml} disabled={!wasmModule}>
        Convert
      </button>
    </div>
  );
}

export default App;

Convert RTF to HTML in React

Get a Free License

To fully experience the capabilities of Spire.Doc for JavaScript without any evaluation limitations, you can request a free 30-day trial license.