Extract OLE Objects from Workbook with JavaScript via C++
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Sometimes, you do need to extract OLE objects from a workbook. Aspose.Cells supports extracting and saving those OLE objects.
This article shows how to create an application in JavaScript via C++ and extract different OLE objects from a workbook with a few simple lines of code.
Extract OLE Objects from a Workbook
Creating a Template Workbook
- Create a workbook in Microsoft Excel.
- Add a Microsoft Word document, an Excel workbook, and a PDF document as OLE objects on the first worksheet.
| Template document with OLE objects (OleFile.xls) |
|---|
 |
Next, extract the OLE objects and save them to the hard disk with their respective file types.
Download and Install Aspose.Cells
- Download Aspose.Cells for JavaScript via C++.
- Install it on your development computer.
All Aspose components, when installed, work in evaluation mode. The evaluation mode has no time limit and it only injects watermarks into produced documents.
Create a Project
Start a JavaScript environment and create a new project. This example will show a browser-based application, but you can use any JavaScript-compatible environment as well.
- Add Dependencies
- Include the Aspose.Cells for JavaScript via C++ script in your HTML page and create a simple UI to select an Excel file and extract OLE objects:
<!DOCTYPE html>
<html>
<head>
<title>Extract OLE Objects</title>
<meta charset="utf-8" />
<style>
body { font-family: Arial, sans-serif; margin: 20px; }
#downloadLink { display: none; margin-top: 10px; }
.ole-link { display: block; margin: 6px 0; }
.info { margin-top: 12px; }
</style>
</head>
<body>
<h1>Extract OLE Objects</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.xlsm,.xlsb" />
<button id="runExample">Run Example</button>
<a id="downloadLink" style="display: none;">Download Result</a>
<div id="result"></div>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, SaveFormat, 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');
const resultDiv = document.getElementById('result');
const primaryDownloadLink = document.getElementById('downloadLink');
resultDiv.innerHTML = '';
primaryDownloadLink.style.display = 'none';
primaryDownloadLink.href = '';
primaryDownloadLink.textContent = '';
if (!fileInput.files.length) {
resultDiv.innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Instantiate workbook from uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
const extractedLinks = [];
let totalExtracted = 0;
// Iterate through all worksheets
const sheetsCount = workbook.worksheets.count;
for (let s = 0; s < sheetsCount; s++) {
const worksheet = workbook.worksheets.get(s);
// Access OLE objects collection on the worksheet
const oleObjects = worksheet.oleObjects;
if (!oleObjects) continue;
const oleCount = oleObjects.count;
for (let o = 0; o < oleCount; o++) {
const ole = oleObjects.get(o);
// Attempt to get a filename from ole properties
// Applying universal getter->property conversion:
// getSourceFullName() -> sourceFullName, getName() -> name, getObjectData() -> objectData
let fileName = ole.sourceFullName || ole.name || `ole_object_sheet${s}_idx${o}.bin`;
// Ensure filename is just the basename
try {
// simple basename extraction
const parts = fileName.split(/[/\\]/);
fileName = parts[parts.length - 1] || fileName;
} catch (e) {
// if something unexpected, fallback
fileName = `ole_object_sheet${s}_idx${o}.bin`;
}
// Get the raw object data as bytes
const objectData = ole.objectData;
// Some runtimes may return a typed array, ArrayBuffer or plain JS array.
let blobData;
if (objectData instanceof ArrayBuffer) {
blobData = new Blob([new Uint8Array(objectData)]);
} else if (ArrayBuffer.isView(objectData)) {
blobData = new Blob([objectData]);
} else if (objectData && objectData.buffer && ArrayBuffer.isView(objectData.buffer)) {
blobData = new Blob([objectData]);
} else if (objectData && objectData.byteLength !== undefined) {
// fallback for objects exposing byteLength
blobData = new Blob([objectData]);
} else {
// If objectData is a normal JS array of bytes
blobData = new Blob([new Uint8Array(objectData)]);
}
const url = URL.createObjectURL(blobData);
// Create a download link element for this OLE object
const a = document.createElement('a');
a.href = url;
a.download = fileName;
a.textContent = `Download extracted OLE object: ${fileName}`;
a.className = 'ole-link';
resultDiv.appendChild(a);
extractedLinks.push({ name: fileName, url });
totalExtracted++;
}
}
if (totalExtracted === 0) {
resultDiv.innerHTML = '<p class="info">No OLE objects were found in the uploaded workbook.</p>';
} else {
// Make the first extracted file available via the primary downloadLink element as well
if (extractedLinks.length) {
primaryDownloadLink.href = extractedLinks[0].url;
primaryDownloadLink.download = extractedLinks[0].name;
primaryDownloadLink.style.display = 'inline-block';
primaryDownloadLink.textContent = `Download First Extracted OLE Object: ${extractedLinks[0].name}`;
}
const summary = document.createElement('p');
summary.className = 'info';
summary.innerHTML = `<strong>Extracted ${totalExtracted} OLE object(s).</strong> Use the links above to download them.`;
resultDiv.insertBefore(summary, resultDiv.firstChild);
}
});
</script>
</html>
```html
<!DOCTYPE html>
<html>
<head>
<title>Extract OLE Objects from Workbook</title>
</head>
<body>
<h1>Extract OLE Objects from Workbook</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx" />
<button id="extractBtn">Extract OLE Objects</button>
<div id="result"></div>
<div id="downloads"></div>
<script src="aspose.cells.js"></script>
<script type="text/javascript">
const { Workbook, FileFormatType, SaveFormat } = AsposeCells;
AsposeCells.onReady().then(() => {
console.log("Aspose.Cells initialized");
});
document.getElementById('extractBtn').addEventListener('click', async () => {
const fileInput = document.getElementById('fileInput');
const result = document.getElementById('result');
const downloads = document.getElementById('downloads');
downloads.innerHTML = '';
if (!fileInput.files.length) {
result.innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Get the OleObject collection in the first worksheet.
const worksheet = workbook.worksheets.get(0);
const oles = worksheet.oleObjects;
const count = oles.count;
if (count === 0) {
result.innerHTML = '<p>No OLE objects found in the workbook.</p>';
return;
}
result.innerHTML = `<p>Found ${count} OLE object(s). Preparing downloads...</p>`;
for (let i = 0; i < count; i++) {
const ole = oles.get(i);
// Specify each file format based on the ole object format type.
let ext = 'bin';
switch (ole.fileFormatType) {
case FileFormatType.Doc:
ext = 'doc';
break;
case FileFormatType.Excel97To2003:
ext = 'xls';
break;
case FileFormatType.Xlsx:
ext = 'xlsx';
break;
case FileFormatType.Ppt:
ext = 'ppt';
break;
case FileFormatType.Pdf:
ext = 'pdf';
break;
case FileFormatType.Unknown:
ext = 'jpg';
break;
default:
ext = 'bin';
break;
}
const fileName = `outOle${i}.${ext}`;
// Save the ole object as a new excel file if the object type is xlsx.
if (ole.fileFormatType === FileFormatType.Xlsx) {
const ms = ole.objectData;
if (ms != null) {
const oleBook = new Workbook(ms);
oleBook.settings.isHidden = false;
const outData = oleBook.save(SaveFormat.Xlsx);
const blob = new Blob([outData], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
const a = document.createElement('a');
a.href = URL.createObjectURL(blob);
a.download = fileName;
a.textContent = `Download ${fileName}`;
downloads.appendChild(a);
downloads.appendChild(document.createElement('br'));
}
} else {
const data = ole.objectData;
if (data != null) {
const blob = new Blob([data]);
const a = document.createElement('a');
a.href = URL.createObjectURL(blob);
a.download = fileName;
a.textContent = `Download ${fileName}`;
downloads.appendChild(a);
downloads.appendChild(document.createElement('br'));
}
}
}
result.innerHTML += '<p style="color: green;">Extraction completed! Use the links above to download the extracted files.</p>';
});
</script>
</body>
</html>