Node.js

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.

Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

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

    var pdf = new chilkat.Pdf();

    //  Load a PDF file.
    //  If the PDF file already has metadata, we'll update it.
    //  Otherwise this example adds the metadata.
    success = pdf.LoadFile("qa_data/pdf/blank_with_metadata.pdf");
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    var xml = new chilkat.Xml();
    var sbExisting = new chilkat.StringBuilder();

    var hasMetadata = pdf.GetMetadata(sbExisting);
    if (hasMetadata == true) {
        xml.LoadSb(sbExisting,true);
    }
    else {

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

        var dt = new chilkat.CkDateTime();
        dt.SetFromCurrentSystemTime();
        var ts = dt.GetAsTimestamp(true);

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

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

        var sbDocId = new chilkat.StringBuilder();
        sbDocId.Append("uuid:");
        sbDocId.AppendUuid(true);
        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmpMM:DocumentID",sbDocId.GetAsString());

        var sbInstanceId = new chilkat.StringBuilder();
        sbInstanceId.Append("uuid:");
        sbInstanceId.AppendUuid(true);
        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmpMM:InstanceID",sbInstanceId.GetAsString());

    }

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

    //  Create a new PDF with the updated metadata.
    var sb = new chilkat.StringBuilder();
    xml.GetXmlSb(sb);
    success = pdf.UpdateMetadata(sb,"c:/temp/qa_output/out.pdf");
    if (success == true) {
        console.log("Success");
    }
    else {
        console.log(pdf.LastErrorText);
    }

    //  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.

    console.log("OK");

}

chilkatExample();