Generate Thumbnail of the Worksheet with JavaScript via C++
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It can be useful to generate thumbnails from worksheets. A thumbnail is a small image that can be pasted into a Word document or a PowerPoint presentation to give a preview of what’s on the worksheet. It can be added to a webpage with a link to download the original document and has a host of other uses.
Aspose.Cells for JavaScript via C++ allows you to output worksheets to image files so making a thumbnail is easy. The sample code below shows you how to output worksheets to image files.
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
</head>
<body>
<h1>Generate Worksheet Thumbnail Example</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="runExample">Generate Thumbnail</button>
<a id="downloadLink" style="display: none;">Download Result</a>
<div id="result"></div>
</body>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, ImageOrPrintOptions, ImageType, SheetRender, Utils } = AsposeCells;
AsposeCells.onReady({
license: "/lic/aspose.cells.enc",
fontPath: "/fonts/",
fontList: [
"arial.ttf",
"NotoSansSC-Regular.ttf"
]
}).then(() => {
console.log("Aspose.Cells initialized");
});
document.getElementById('runExample').addEventListener('click', async () => {
const fileInput = document.getElementById('fileInput');
if (!fileInput.files.length) {
document.getElementById('result').innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Instantiate and open an Excel file from the uploaded file
const book = new Workbook(new Uint8Array(arrayBuffer));
// Define ImageOrPrintOptions
const imgOptions = new ImageOrPrintOptions();
// Specify the image format
imgOptions.imageType = ImageType.Jpeg;
// Set the vertical and horizontal resolution
imgOptions.verticalResolution = 200;
imgOptions.horizontalResolution = 200;
// One page per sheet is enabled
imgOptions.onePagePerSheet = true;
// Set desired thumbnail dimensions (converted to a property assignment)
imgOptions.desiredSize = [600, 600, true];
// Get the first worksheet
const sheet = book.worksheets.get(0);
// Render the sheet with respect to specified image/print options
const sr = new SheetRender(sheet, imgOptions);
// Generate the image for the first page (index 0)
const outputData = sr.toImage(0);
// Create a blob and provide a download link
const blob = new Blob([outputData], { type: 'image/jpeg' });
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'outputGenerateThumbnailOfWorksheet.jpg';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Thumbnail Image';
document.getElementById('result').innerHTML = '<p style="color: green;">Thumbnail generated successfully! Click the download link to get the image.</p>';
});
</script>
</html>