Unicode C

PDF Update or Add XML Metadata

Demonstrates how to add or update the XML metadata stored in a PDF.

Note: This example requires Chilkat v10.1.0 or later.

Unicode C

#include <C_CkPdfW.h>
#include <C_CkXmlW.h>
#include <C_CkStringBuilderW.h>
#include <C_CkDateTimeW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdfW pdf;
    HCkXmlW xml;
    HCkStringBuilderW sbExisting;
    BOOL hasMetadata;
    HCkDateTimeW dt;
    const wchar_t *ts;
    HCkStringBuilderW sbDocId;
    HCkStringBuilderW sbInstanceId;
    HCkStringBuilderW sb;

    success = FALSE;

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

    pdf = CkPdfW_Create();

    // Load a PDF file.
    // If the PDF file already has metadata, we'll update it.
    // Otherwise this example adds the metadata.
    success = CkPdfW_LoadFile(pdf,L"qa_data/pdf/blank_with_metadata.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    xml = CkXmlW_Create();
    sbExisting = CkStringBuilderW_Create();

    hasMetadata = CkPdfW_GetMetadata(pdf,sbExisting);
    if (hasMetadata == TRUE) {
        CkXmlW_LoadSb(xml,sbExisting,TRUE);
    }
    else {

        // Otherwise create the bare minimum XMP metadata.
        CkXmlW_putTag(xml,L"x:xmpmeta");
        CkXmlW_AddAttribute(xml,L"xmlns:x",L"adobe:ns:meta/");
        CkXmlW_AddAttribute(xml,L"x:xmptk",L"Adobe XMP Core 9.1-c001 79.675d0f7, 2023/06/11-19:21:16 ");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF",TRUE,L"xmlns:rdf",L"http://www.w3.org/1999/02/22-rdf-syntax-ns#");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"rdf:about",L"");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"xmlns:xmp",L"http://ns.adobe.com/xap/1.0/");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"xmlns:dc",L"http://purl.org/dc/elements/1.1/");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"xmlns:xmpMM",L"http://ns.adobe.com/xap/1.0/mm/");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"xmlns:pdf",L"http://ns.adobe.com/pdf/1.3/");
        CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"xmlns:xmpRights",L"http://ns.adobe.com/xap/1.0/rights/");

        dt = CkDateTimeW_Create();
        CkDateTimeW_SetFromCurrentSystemTime(dt);
        ts = CkDateTimeW_getAsTimestamp(dt,TRUE);

        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|xmp:ModifyDate",ts);
        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|xmp:CreateDate",ts);
        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|xmp:MetadataDate",ts);

        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|xmp:CreatorTool",L"My Custom Application");
        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|dc:format",L"application/pdf");

        sbDocId = CkStringBuilderW_Create();
        CkStringBuilderW_Append(sbDocId,L"uuid:");
        CkStringBuilderW_AppendUuid(sbDocId,TRUE);
        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|xmpMM:DocumentID",CkStringBuilderW_getAsString(sbDocId));

        sbInstanceId = CkStringBuilderW_Create();
        CkStringBuilderW_Append(sbInstanceId,L"uuid:");
        CkStringBuilderW_AppendUuid(sbInstanceId,TRUE);
        CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|xmpMM:InstanceID",CkStringBuilderW_getAsString(sbInstanceId));

    }

    // Add our custom metadata tags to either the existing XML metdata, or the newly created metadata.
    CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"xmlns:zf",L"urn:ferd:pdfa:CrossIndustryDocument:invoice:1p0#");
    CkXmlW_UpdateAttrAt(xml,L"rdf:RDF|rdf:Description",TRUE,L"rdf:about",L" ");
    CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|zf:ConformanceLevel",L"BASIC");
    CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|zf:DocumentFileName",L"ZZZZZZ-invoice.xml");
    CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|zf:DocumentType",L"INVOICE");
    CkXmlW_UpdateChildContent(xml,L"rdf:RDF|rdf:Description|zf:Version",L"1.0");

    // Create a new PDF with the updated metadata.
    sb = CkStringBuilderW_Create();
    CkXmlW_GetXmlSb(xml,sb);
    success = CkPdfW_UpdateMetadata(pdf,sb,L"c:/temp/qa_output/out.pdf");
    if (success == TRUE) {
        wprintf(L"Success\n");
    }
    else {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
    }

    // To see the metadata in Adobe Acrobat DC,
    // 1) Open the PDF.
    // 2) CTRL-D to show the Document Properties dialog.
    // 3) In the dialog, click on the "Additional Metadata" button.
    // 4) In the Additional Data dialog, click on "Advanced"
    // 5) Expand the namespace tree for the metadata you added.

    wprintf(L"OK\n");


    CkPdfW_Dispose(pdf);
    CkXmlW_Dispose(xml);
    CkStringBuilderW_Dispose(sbExisting);
    CkDateTimeW_Dispose(dt);
    CkStringBuilderW_Dispose(sbDocId);
    CkStringBuilderW_Dispose(sbInstanceId);
    CkStringBuilderW_Dispose(sb);

    }