Go

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.

Go

    success := false

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

    pdf := chilkat.NewPdf()

    success = pdf.LoadFile("qa_data/pdf/embedded_files/my_embedded_files_test.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        return
    }

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

    // How many embedded files exist within the opened PDF?
    numFiles := pdf.NumEmbeddedFiles()
    fmt.Println("Number of embedded files: ", numFiles)

    json := chilkat.NewJsonObject()
    json.SetEmitCompact(false)

    bd := chilkat.NewBinData()

    // Get information about each file, and extract each to the filesystem.
    i := 0
    for i < numFiles {

        success = pdf.GetEmbeddedFileInfo(i,json)
        if success == false {
            fmt.Println(pdf.LastErrorText())
            pdf.DisposePdf()
            json.DisposeJsonObject()
            bd.DisposeBinData()
            return
        }

        fmt.Println(*json.Emit())

        // Get the filename from the JSON.
        var filename *string = new(string)
        *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 {
            fmt.Println(pdf.LastErrorText())
            pdf.DisposePdf()
            json.DisposeJsonObject()
            bd.DisposeBinData()
            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 {
            fmt.Println("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'"
    // }

    pdf.DisposePdf()
    json.DisposeJsonObject()
    bd.DisposeBinData()