Secure PDF Documents with JavaScript via C++
Contents
[
Hide
]
Sometimes, developers need to work with encrypted PDF files. For example:
- Secure the documents with owner and user passwords so not just anyone can open it.
- Set restrictions or permissions to the document after the document is opened. e.g. restrict whether the document content can be printed or extracted.
This article explains how to pass in PDF security options when saving spreadsheets to PDF.
Aspose.Cells provides PdfSecurityOptions for working with security. You can set owner and user passwords while saving to PDF. The owner password or user password will be required to open the encrypted PDF document for viewing.
- The user password can be null or an empty string; in this case, no password will be required from the user when opening the PDF document.
- Opening the PDF document with the correct owner password allows full access (without any access restrictions specified) to the document.
- Opening the PDF document with the correct user password (or opening a document that does not have a user password) allows limited access as the permissions specified.
The sample code below describes how to secure PDFs with Aspose.Cells.
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Secure PDF Example</title>
</head>
<body>
<h1>Secure PDF Example</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx" />
<button id="runExample">Run Example</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, SaveFormat, PdfSaveOptions, PdfSecurityOptions, 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();
// Instantiating a Workbook object from the uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Create PDF save options and security options
const saveOption = new PdfSaveOptions();
saveOption.securityOptions = new PdfSecurityOptions();
// Set security options (converted from getters/setters to properties)
saveOption.securityOptions.userPassword = "user";
saveOption.securityOptions.ownerPassword = "owner";
saveOption.securityOptions.extractContentPermission = false;
saveOption.securityOptions.printPermission = false;
// Save the workbook to PDF with security options
const outputData = workbook.save(SaveFormat.Pdf, saveOption);
const blob = new Blob([outputData], { type: "application/pdf" });
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'securepdf_test.out.pdf';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Secure PDF';
document.getElementById('result').innerHTML = '<p style="color: green;">PDF generated successfully! Click the download link to get the secured PDF file.</p>';
});
</script>
</html>
If the spreadsheet contains formulas, it is best to call Workbook.calculateFormula() just before rendering it to PDF. This ensures that formula dependent values are recalculated and the correct values are rendered in the PDF.