JavaScript

Extract Embedded Files from PDF

Demonstrates how to get information about the embedded files (if any) contained within a PDF, and shows how to extract each file.

Note: This example requires Chilkat v9.5.0.95 or greater.

JavaScript

var success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

var pdf = new CkPdf();

success = pdf.LoadFile("qa_data/pdf/embedded_files/my_embedded_files_test.pdf");
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

// Note: The embedded file functionality was added in Chilkat v9.5.0.95

// How many embedded files exist within the opened PDF?
var numFiles = pdf.NumEmbeddedFiles;
console.log("Number of embedded files: " + numFiles);

var json = new CkJsonObject();
json.EmitCompact = false;

var bd = new CkBinData();

// Get information about each file, and extract each to the filesystem.
var i = 0;
while (i < numFiles) {

    success = pdf.GetEmbeddedFileInfo(i,json);
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    console.log(json.Emit());

    // Get the filename from the JSON.
    var filename = "someFile.dat";

    // The filename SHOULD always be present..
    if (json.HasMember("filename") == true) {
        filename = json.StringOf("filename");
    }

    // Get the file data.
    success = pdf.GetEmbeddedFileBd(i,bd);
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    // Save the contents of the bd to the filename (in the current working directory) in the filesystem.
    success = bd.WriteFile(filename);
    if (success == false) {
        console.log("Failed to write output file.");
    }

    i = i+1;
}

// Sample output for the above code:

// Number of embedded files: 3
// {
//   "filename": "employees.json",
//   "desc": "JSON",
//   "subType": "application/json",
//   "size": 159,
//   "creationDate": "D:20230715170506-05'00'",
//   "modDate": "D:20160207153838-05'00'"
// }
// 
// {
//   "filename": "rsaPubKey.pem",
//   "desc": "RSA Public Key PEM",
//   "size": 451,
//   "creationDate": "D:20230715170546-05'00'",
//   "modDate": "D:20150724133153-05'00'"
// }
// 
// {
//   "filename": "starfish.jpg",
//   "desc": "Starfish JPG",
//   "subType": "image/jpeg",
//   "size": 6229,
//   "creationDate": "D:20230715170356-05'00'",
//   "modDate": "D:20080529103055-05'00'"
// }