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Transforming PDF documents into image formats like JPG or PNG is a powerful way to enhance the accessibility and usability of your content. By converting PDF pages into images, you preserve the original layout and design, making it ideal for various applications, from online sharing to incorporation in websites and presentations.
In this article, you will learn how to convert PDF files to images in React using Spire.PDF for JavaScript. We will guide you through the process step-by-step, ensuring you can easily generate high-quality images from your PDF documents.
Install Spire.PDF for JavaScript
To get started with converting PDF to images with JavaScript in a React application, you can either download Spire.PDF for JavaScript from our website or install it via npm with the following command:
npm i spire.pdf
After that, copy the "Spire.Pdf.Base.js" and "Spire.Pdf.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.PDF for JavaScript in a React Project
Convert PDF to JPG in React
Spire.PDF for JavaScript provides the PdfDocument.SaveAsImage() method to convert a specific page of a PDF into image byte data, which can then be saved as a JPG file using the Save() method. To convert all pages into individual images, iterate through each page.
The following are the steps to convert PDF to JPG in React:
- Load the required font files and the input PDF file into the Virtual File System (VFS).
- Create a PdfDocument object with the wasmModule.PdfDocument.Create() method.
- Load the PDF using the PdfDocument.LoadFromFile() method.
- Iterate through the document's pages:
- Convert each page into image byte data using the PdfDocument.SaveAsImage() method.
- Save the image as a JPG file using the Save() method.
- Trigger the download of the generated JPG file.
- 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 spirepdf from the global window object
const { Module, spirepdf } = window;
// Set the wasmModule state when the runtime is initialized
Module.onRuntimeInitialized = () => {
setWasmModule(spirepdf);
};
} 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 = `${process.env.PUBLIC_URL}/Spire.Pdf.Base.js`;
script.onload = loadWasm;
// Append the script to the document body
document.body.appendChild(script);
// Cleanup function to remove the script when the component unmounts
return () => {
document.body.removeChild(script);
};
}, []);
// Function to convert PDF to JPG
const ConvertPdfToJpg = async () => {
if (wasmModule) {
// Load the necessary font files into the virtual file system (VFS)
await wasmModule.FetchFileToVFS('GOTHIC.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICB.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICBI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
// Load the input PDF file into the VFS
let inputFileName = 'input.pdf';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new document
const doc = wasmModule.PdfDocument.Create();
// Load the PDF file
doc.LoadFromFile(inputFileName);
// Iterate through the pages in the document
for (let i = 0; i < doc.Pages.Count; i++) {
// Specify the output file name
let outputFileName = `ToImage-img-${i}.jpg`;
// Save the specific page to image data
let imageData = doc.SaveAsImage({pageIndex: i});
// Save the image data as a JPG file
imageData.Save(outputFileName);
// Read the generated JPG file
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
// Create a Blob object from the JPG file
const modifiedFile = new Blob([modifiedFileArray], { type:'image/jpeg' });
// 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 PDF to JPG in React</h1>
<button onClick={ConvertPdfToJpg} 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.
Here is a screenshot of the generated JPG files:
Convert PDF to PNG in React
To convert a PDF document into individual PNG files, iterate through its pages and use the PdfDocument.SaveAsImage() method to generate image byte data for each page. Then, save these byte data as PNG files.
The following are the steps to convert PDF to PNG in React:
- Load the required font files and the input PDF file into the Virtual File System (VFS).
- Create a PdfDocument object with the wasmModule.PdfDocument.Create() method.
- Load the PDF using the PdfDocument.LoadFromFile() method.
- Iterate through the document's pages:
- Convert each page into image byte data using the PdfDocument.SaveAsImage() method.
- Save the image as a PNG file using the Save() method.
- Trigger the download of the generated PNG file.
- 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 spirepdf from the global window object
const { Module, spirepdf } = window;
// Set the wasmModule state when the runtime is initialized
Module.onRuntimeInitialized = () => {
setWasmModule(spirepdf);
};
} 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.Pdf.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 PDF to PNG
const ConvertPdfToPng = async () => {
if (wasmModule) {
// Load the necessary font files into the virtual file system (VFS)
await wasmModule.FetchFileToVFS('GOTHIC.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICB.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICBI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
// Load the input PDF file into the VFS
let inputFileName = 'input.pdf';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new document
const doc = wasmModule.PdfDocument.Create();
// Load the PDF file
doc.LoadFromFile(inputFileName);
// Make background of the generated images transparent
// doc.ConvertOptions.SetPdfToImageOptions(0);
// Iterate through the pages in the document
for (let i = 0; i < doc.Pages.Count; i++) {
// Specify the output file name
let outputFileName = `ToImage-img-${i}.png`;
// Save the specific page to image data
let imageData = doc.SaveAsImage({pageIndex: i});
// Save the image data as a PNG file
imageData.Save(outputFileName);
// Read the generated PNG file
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
// Create a Blob object from the PNG file
const modifiedFile = new Blob([modifiedFileArray], { type:'image/png' });
// 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 PDF to PNG in React</h1>
<button onClick={ConvertPdfToPng} disabled={!wasmModule}>
Convert
</button>
</div>
);
}
export default App;
Convert PDF to SVG in React
To convert each page of a PDF document into individual SVG files, you can utilize the PdfDocument.SaveToFile() method. Here are the detailed steps:
- Load the required font files and the input PDF file into the Virtual File System (VFS).
- Create a PdfDocument object with the wasmModule.PdfDocument.Create() method.
- Load the PDF using the PdfDocument.LoadFromFile() method.
- Iterate through the pages:
- Convert each page into an SVG file using the PdfDocument.SaveToFile() method.
- Trigger the download of the generated SVG file.
- 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 spirepdf from the global window object
const { Module, spirepdf } = window;
// Set the wasmModule state when the runtime is initialized
Module.onRuntimeInitialized = () => {
setWasmModule(spirepdf);
};
} 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 = `${process.env.PUBLIC_URL}/Spire.Pdf.Base.js`;
script.onload = loadWasm;
// Append the script to the document body
document.body.appendChild(script);
// Cleanup function to remove the script when the component unmounts
return () => {
document.body.removeChild(script);
};
}, []);
// Function to convert PDF to SVG
const ConvertPdfToSvg = async () => {
if (wasmModule) {
// Load the necessary font files into the virtual file system (VFS)
await wasmModule.FetchFileToVFS('GOTHIC.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICB.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICBI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
await wasmModule.FetchFileToVFS('GOTHICI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
// Load the input PDF file into the VFS
let inputFileName = 'input.pdf';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new document
const doc = wasmModule.PdfDocument.Create();
// Load the PDF file
doc.LoadFromFile(inputFileName);
// Iterate through the pages in the document
for (let i = 0; i < doc.Pages.Count; i++) {
// Specify the output file name
let outputFileName = `ToSVG_${i}.svg`;
// Save a specfic page to SVG
doc.SaveToFile({fileName: outputFileName, startIndex:i, endIndex:i, fileFormat: wasmModule.FileFormat.SVG});
// Read the generated SVG file
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
// Create a Blob object from the SVG file
const modifiedFile = new Blob([modifiedFileArray], { type:'image/svg+xml' });
// 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 PDF to SVG in React</h1>
<button onClick={ConvertPdfToSvg} disabled={!wasmModule}>
Convert
</button>
</div>
);
}
export default App;
Get a Free License
To fully experience the capabilities of Spire.PDF for JavaScript without any evaluation limitations, you can request a free 30-day trial license.
Published in
Conversion
Tagged under
When reviewing a long document, the find and highlight feature allows users to quickly locate specific information. For example, if there are multiple people working on a research paper, the find and highlight feature can be used to flag important points or areas that need attention, making it easier for others to focus on those specific parts. This article will demonstrate how to find and highlight text in a Word document in React using Spire.Doc for JavaScript.
- Find and Highlight the First Instance of Specified Text in Word
- Find and Highlight All Instances of Specified Text in Word
Install the JavaScript Library
To get started with inserting images in Word 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 into the public folder of your project.
For more details, refer to the documentation: How to Integrate Spire.Doc for JavaScript in a React Project
Find and Highlight the First Instance of Specified Text in Word in JavaScript
The Document.FindString() method allows to find the first instance of a specified text and then you can set a highlight color for it through the TextRange.CharacterFormat.HighlightColor property. The following are the main steps:
- Create a new document using the wasmModule.Document.Create() method.
- Load a Word document using the Document.LoadFromFile() method.
- Find the first instance of a specific text using the Document.FindString() method.
- Get the instance as a single text range using the TextSelection.GetAsOneRange() method, and then highlight the text range with a background color using the TextRange.CharacterFormat.HighlightColor property.
- Save the result document using Document.SaveToFile() method.
- 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 find and higlight a specified text in Word
const FindHighlightFirst = async () => {
if (wasmModule) {
// Load the sample file into the virtual file system (VFS)
let inputFileName = 'Spire.docx';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new document
const doc = wasmModule.Document.Create();
// Load the Word document
doc.LoadFromFile(inputFileName);
// Find the first instance of a specific text
let textSelection = doc.FindString('Spire.Doc for JavaScript', false, true);
// Get the instance as a single text range
let textRange = textSelection.GetAsOneRange();
// Set highlight color
textRange.CharacterFormat.HighlightColor = wasmModule.Color.get_Yellow();
// Save the result document
const outputFileName = 'FindHighlightFirst.docx';
doc.SaveToFile({ fileName: outputFileName, fileFormat: wasmModule.FileFormat.Docx2013 });
// Release resources
doc.Dispose();
// Read the generated Word file from VFS
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
// Create a Blob object from the Word file
const modifiedFile = new Blob([modifiedFileArray], { type: "application/vnd.openxmlformats-officedocument.wordprocessingml.document" });
// 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);
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Find and Highlight Specified Text in Word Using JavaScript in React</h1>
<button onClick={FindHighlightFirst} disabled={!wasmModule}>
Execute
</button>
</div>
);
}
export default App;
Run the code to launch the React app at localhost:3000. Once it's running, click on the "Execute" button to download the result file:
The result file:
Find and Highlight All Instances of Specified Text in Word in JavaScript
Spire.Doc for JavaScript also provides the Document.FindAllString() method to find all instances of a specified text in a Word document. Then you can iterate through these instances and highlight each one with a background color. The following are the main steps:
- Create a new document using the wasmModule.Document.Create() method.
- Load a Word document using the Document.LoadFromFile() method.
- Find all instances of a specific text in the document using the Document.FindAllString() method.
- Iterate through each found instance and get it as a single text range using the TextSelection.GetAsOneRange() method, then highlight each text range with a bright color using the TextRange.CharacterFormat.HighlightColor property.
- Save the result document using Document.SaveToFile() method.
- 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 find and higlight a specified text in Word
const FindAndHighlightAll = async () => {
if (wasmModule) {
// Load the sample file into the virtual file system (VFS)
let inputFileName = 'Spire.docx';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new document
const doc = wasmModule.Document.Create();
// Load the Word document
doc.LoadFromFile(inputFileName);
// Find all occurrences of the specified text in the document
let textSelections = doc.FindAllString('Spire.Doc for JavaScript', false, true);
// Iterate through all found text selections
for (let i = 0; i < textSelections.length; i++) {
let selection = textSelections[i];
// Set highlight color
selection.GetAsOneRange().CharacterFormat.HighlightColor = wasmModule.Color.get_Yellow();
}
// Save the result document
const outputFileName = 'FindAndHighlight.docx';
doc.SaveToFile({ fileName: outputFileName, fileFormat: wasmModule.FileFormat.Docx2013 });
// Release resources
doc.Dispose();
// Read the generated Word file from VFS
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
// Create a Blob object from the Word file
const modifiedFile = new Blob([modifiedFileArray], { type: "application/vnd.openxmlformats-officedocument.wordprocessingml.document" });
// 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);
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Find and Highlight Specified Text in Word Using JavaScript in React</h1>
<button onClick={FindAndHighlightAll} disabled={!wasmModule}>
Execute
</button>
</div>
);
}
export default App;
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.
Published in
Text
Tagged under
Lock Cells, Rows, and Columns in Excel with JavaScript in React
2025-03-11 01:57:59 Written by AdministratorWhen working with Excel, you may sometimes need to protect critical data while allowing users to edit other parts of the worksheet. This is especially important for scenarios where certain formulas, headers, or reference values must remain unchanged to ensure data integrity. By locking specific areas, you can prevent accidental modifications, maintain consistency, and control access to key information within the spreadsheet. In this article, you will learn how to lock cells, rows, and columns in Excel in React using JavaScript and the Spire.XLS for JavaScript library.
Install Spire.XLS for JavaScript
To get started with locking cells, rows, and columns in Excel files within 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.xls
After that, copy the "Spire.Xls.Base.js" and "Spire.Xls.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.XLS for JavaScript in a React Project
Lock Cells in Excel
Spire.XLS for JavaScript offers the Worksheet.Range.get().Style.Locked property, allowing you to protect critical data cells while enabling edits to the rest of the worksheet. The detailed steps are as follows.
- Create a Workbook object using the wasmModule.Workbook.Create() method.
- Load a sample Excel file using the Workbook.LoadFromFile() method.
- Get the first worksheet using the Workbook.Worksheets.get() method.
- Unlock all cells in the used range of the worksheet by setting the Worksheet.Range.Style.Locked property to "false".
- Set text for specific cells using the Worksheet.Range.get().Text property and then lock them by setting the Worksheet.Range.get().Style.Locked property to "true".
- Protect the worksheet with a password using the Worksheet.Protect() method.
- Save the result file using the Workbook.SaveToFile() method.
- 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 spirexls from the global window object
const { Module, spirexls } = window;
// Set the wasmModule state when the runtime is initialized
Module.onRuntimeInitialized = () => {
setWasmModule(spirexls);
};
} 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.Xls.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 lock specific cells in Excel
const LockExcelCells = async () => {
if (wasmModule) {
// Load the ARIALUNI.TTF font file into the virtual file system (VFS)
await wasmModule.FetchFileToVFS('ARIALUNI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
// Load the input Excel file into the virtual file system (VFS)
const inputFileName = 'Sample.xlsx';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new workbook
const workbook = wasmModule.Workbook.Create();
// Load the Excel file from the virtual file system
workbook.LoadFromFile({fileName: inputFileName});
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Unlock all cells in the used range of the worksheet
sheet.Range.Style.Locked = false;
// Lock a specific cell in the worksheet
sheet.Range.get("A1").Text = "Locked";
sheet.Range.get("A1").Style.Locked = true;
// Lock a specific cell range in the worksheet
sheet.Range.get("C1:E3").Text = "Locked";
sheet.Range.get("C1:E3").Style.Locked = true;
// Protect the worksheet with a password
sheet.Protect({password: "123", options: wasmModule.SheetProtectionType.All});
let outputFileName = "LockCells.xlsx";
// Save the resulting file
workbook.SaveToFile({ fileName: outputFileName, version: wasmModule.ExcelVersion.Version2013 });
// Read the saved file and convert it to a Blob object
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
// Create a URL for the Blob and initiate the 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 workbooks
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Lock Specific Cells in Excel Using JavaScript in React</h1>
<button onClick={LockExcelCells} disabled={!wasmModule}>
Lock
</button>
</div>
);
}
export default App;
Run the code to launch the React app at localhost:3000. Once it's running, click on the "Lock" button to lock specific cells in the Excel file:
Upon opening the output Excel sheet and attempting to edit the protected cells, a dialog box will appear, notifying you that the cell you're trying to change is on a protected sheet:
Lock Rows in Excel
If you need to preserve row-based data, such as headers or summaries, you can lock entire rows using the Worksheet.Rows.get().Style.Locked property in Spire.XLS for JavaScript. The detailed steps are as follows.
- Create a Workbook object using the wasmModule.Workbook.Create() method.
- Load a sample Excel file using the Workbook.LoadFromFile() method.
- Get the first worksheet using the Workbook.Worksheets.get() method.
- Unlock all cells in the used range of the worksheet by setting the Worksheet.Range.Style.Locked property to "false".
- Set text for a specific row using the Worksheet.Rows.get().Text property and then lock it by setting the Worksheet.Rows.get().Style.Locked property to "true".
- Protect the worksheet with a password using the Worksheet.Protect() method.
- Save the result file using the Workbook.SaveToFile() method.
- 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 spirexls from the global window object
const { Module, spirexls } = window;
// Set the wasmModule state when the runtime is initialized
Module.onRuntimeInitialized = () => {
setWasmModule(spirexls);
};
} 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 = `${process.env.PUBLIC_URL}/Spire.Xls.Base.js`;
script.onload = loadWasm;
// Append the script to the document body
document.body.appendChild(script);
// Cleanup function to remove the script when the component unmounts
return () => {
document.body.removeChild(script);
};
}, []);
// Function to lock specific rows in Excel
const LockExcelRows = async () => {
if (wasmModule) {
// Load the ARIALUNI.TTF font file into the virtual file system (VFS)
await wasmModule.FetchFileToVFS('ARIALUNI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
// Load the input Excel file into the virtual file system (VFS)
const inputFileName = 'Sample.xlsx';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new workbook
const workbook = wasmModule.Workbook.Create();
// Load the Excel file from the virtual file system
workbook.LoadFromFile({fileName: inputFileName});
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Unlock all cells in the used range of the worksheet
sheet.Range.Style.Locked = false;
// Lock the third row in the worksheet
sheet.Rows.get(2).Text = "Locked";
sheet.Rows.get(2).Style.Locked = true;
// Protect the worksheet with a password
sheet.Protect({password: "123", options: wasmModule.SheetProtectionType.All});
let outputFileName = "LockRows.xlsx";
// Save the resulting file
workbook.SaveToFile({ fileName: outputFileName, version: wasmModule.ExcelVersion.Version2013 });
// Read the saved file and convert it to a Blob object
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
// Create a URL for the Blob and initiate the 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 workbooks
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Lock Specific Rows in Excel Using JavaScript in React</h1>
<button onClick={LockExcelRows} disabled={!wasmModule}>
Lock
</button>
</div>
);
}
export default App;
Lock Columns in Excel
To maintain the integrity of key vertical data, such as fixed identifiers or category labels, you can lock entire columns using the Worksheet.Columns.get().Style.Locked property in Spire.XLS for JavaScript. The detailed steps are as follows.
- Create a Workbook object using the wasmModule.Workbook.Create() method.
- Load a sample Excel file using the Workbook.LoadFromFile() method.
- Get the first worksheet using the Workbook.Worksheets.get() method.
- Unlock all cells in the used range of the worksheet by setting the Worksheet.Range.Style.Locked property to "false".
- Set text for a specific column using the Worksheet.Columns.get().Text property and then lock it by setting the Worksheet.Columns.get().Style.Locked property to "true".
- Protect the worksheet with a password using the Worksheet.Protect() method.
- Save the result file using the Workbook.SaveToFile() method.
- 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 spirexls from the global window object
const { Module, spirexls } = window;
// Set the wasmModule state when the runtime is initialized
Module.onRuntimeInitialized = () => {
setWasmModule(spirexls);
};
} 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.Xls.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 lock specific columns in Excel
const LockExcelColumns = async () => {
if (wasmModule) {
// Load the ARIALUNI.TTF font file into the virtual file system (VFS)
await wasmModule.FetchFileToVFS('ARIALUNI.TTF', '/Library/Fonts/', `${process.env.PUBLIC_URL}/`);
// Load the input Excel file into the virtual file system (VFS)
const inputFileName = 'Sample.xlsx';
await wasmModule.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/`);
// Create a new workbook
const workbook = wasmModule.Workbook.Create();
// Load the Excel file from the virtual file system
workbook.LoadFromFile({fileName: inputFileName});
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Unlock all cells in the used range of the worksheet
sheet.Range.Style.Locked = false;
// Lock the fourth column in the worksheet
sheet.Columns.get(3).Text = "Locked";
sheet.Columns.get(3).Style.Locked = true;
// Protect the worksheet with a password
sheet.Protect({password: "123", options: wasmModule.SheetProtectionType.All});
let outputFileName = "LockColumns.xlsx";
// Save the resulting file
workbook.SaveToFile({ fileName: outputFileName, version: wasmModule.ExcelVersion.Version2013 });
// Read the saved file and convert it to a Blob object
const modifiedFileArray = wasmModule.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
// Create a URL for the Blob and initiate the 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 workbooks
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Lock Specific Columns in Excel Using JavaScript in React</h1>
<button onClick={LockExcelColumns} disabled={!wasmModule}>
Lock
</button>
</div>
);
}
export default App;
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