C++

Extract Metadata XML from PDF

See more PDF Signatures Examples

Demonstrates how to extract the metadata XML from a PDF. C++

#include <CkPdf.h>
#include <CkStringBuilder.h>
#include <CkXml.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkPdf pdf;

    success = pdf.LoadFile("qa_data/pdf/blank_with_metadata.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    CkStringBuilder sbXml;
    // Note: Not all PDF files have metadata.  Metadata is optional.
    success = pdf.GetMetadata(sbXml);
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    CkXml xml;
    xml.LoadSb(sbXml,true);

    std::cout << xml.getXml() << "\r\n";

    // Sample PDF metadata XML:
    // (Code for parsing follows)

    // Use this online tool to generate parsing code from sample XML: 
    // Generate Parsing Code from XML

    // <?xml version="1.0" encoding="utf-8"?>
    // <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 9.1-c001 79.675d0f7, 2023/06/11-19:21:16        ">
    //     <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
    //         <rdf:Description rdf:about="" xmlns:xmp="http://ns.adobe.com/xap/1.0/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/" xmlns:pdf="http://ns.adobe.com/pdf/1.3/" xmlns:xmpRights="http://ns.adobe.com/xap/1.0/rights/">
    //             <xmp:ModifyDate>2024-11-27T11:33:12-06:00</xmp:ModifyDate>
    //             <xmp:CreateDate>2024-11-27T11:28:23-06:00</xmp:CreateDate>
    //             <xmp:MetadataDate>2024-11-27T11:33:12-06:00</xmp:MetadataDate>
    //             <xmp:CreatorTool>Adobe Acrobat Pro (32-bit) 24.3.20112</xmp:CreatorTool>
    //             <dc:format>application/pdf</dc:format>
    //             <dc:title>
    //                 <rdf:Alt>
    //                     <rdf:li xml:lang="x-default">Blank</rdf:li>
    //                 </rdf:Alt>
    //             </dc:title>
    //             <dc:creator>
    //                 <rdf:Bag>
    //                     <rdf:li>Chilkat Software</rdf:li>
    //                 </rdf:Bag>
    //             </dc:creator>
    //             <dc:description>
    //                 <rdf:Alt>
    //                     <rdf:li xml:lang="x-default">Blank Document</rdf:li>
    //                 </rdf:Alt>
    //             </dc:description>
    //             <dc:subject>
    //                 <rdf:Bag>
    //                     <rdf:li>blank</rdf:li>
    //                     <rdf:li>metadata</rdf:li>
    //                     <rdf:li>document</rdf:li>
    //                 </rdf:Bag>
    //             </dc:subject>
    //             <xmpMM:DocumentID>uuid:34535ffa-b632-43f1-b1fd-80cea6fdc351</xmpMM:DocumentID>
    //             <xmpMM:InstanceID>uuid:69ace620-4c54-407f-8d45-6eebc90f34c2</xmpMM:InstanceID>
    //             <pdf:Producer>Adobe Acrobat Pro (32-bit) 24.3.20112</pdf:Producer>
    //             <pdf:Keywords>blank; metadata; document</pdf:Keywords>
    //             <xmpRights:WebStatement>https://www.chilkatsoft.com/</xmpRights:WebStatement>
    //         </rdf:Description>
    //     </rdf:RDF>
    // </x:xmpmeta>

    const char *x_xmpmeta_xmlns_x = xml.getAttrValue("xmlns:x");
    const char *x_xmpmeta_x_xmptk = xml.getAttrValue("x:xmptk");
    const char *rdf_RDF_xmlns_rdf = xml.chilkatPath("rdf:RDF|(xmlns:rdf)");
    const char *rdf_Description_rdf_about = xml.chilkatPath("rdf:RDF|rdf:Description|(rdf:about)");
    const char *rdf_Description_xmlns_xmp = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:xmp)");
    const char *rdf_Description_xmlns_dc = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:dc)");
    const char *rdf_Description_xmlns_xmpMM = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:xmpMM)");
    const char *rdf_Description_xmlns_pdf = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:pdf)");
    const char *rdf_Description_xmlns_xmpRights = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:xmpRights)");
    const char *xmp_ModifyDate = xml.getChildContent("rdf:RDF|rdf:Description|xmp:ModifyDate");
    const char *xmp_CreateDate = xml.getChildContent("rdf:RDF|rdf:Description|xmp:CreateDate");
    const char *xmp_MetadataDate = xml.getChildContent("rdf:RDF|rdf:Description|xmp:MetadataDate");
    const char *xmp_CreatorTool = xml.getChildContent("rdf:RDF|rdf:Description|xmp:CreatorTool");
    const char *dc_format = xml.getChildContent("rdf:RDF|rdf:Description|dc:format");
    const char *rdf_li_xml_lang = xml.chilkatPath("rdf:RDF|rdf:Description|dc:title|rdf:Alt|rdf:li|(xml:lang)");
    const char *rdf_li = xml.getChildContent("rdf:RDF|rdf:Description|dc:title|rdf:Alt|rdf:li");
    rdf_li = xml.getChildContent("rdf:RDF|rdf:Description|dc:creator|rdf:Bag|rdf:li");
    rdf_li_xml_lang = xml.chilkatPath("rdf:RDF|rdf:Description|dc:description|rdf:Alt|rdf:li|(xml:lang)");
    rdf_li = xml.getChildContent("rdf:RDF|rdf:Description|dc:description|rdf:Alt|rdf:li");
    int i = 0;
    int count_i = xml.NumChildrenHavingTag("rdf:RDF|rdf:Description|dc:subject|rdf:Bag|rdf:li");
    while (i < count_i) {
        xml.put_I(i);
        rdf_li = xml.getChildContent("rdf:RDF|rdf:Description|dc:subject|rdf:Bag|rdf:li[i]");
        i = i + 1;
    }

    const char *xmpMM_DocumentID = xml.getChildContent("rdf:RDF|rdf:Description|xmpMM:DocumentID");
    const char *xmpMM_InstanceID = xml.getChildContent("rdf:RDF|rdf:Description|xmpMM:InstanceID");
    const char *pdf_Producer = xml.getChildContent("rdf:RDF|rdf:Description|pdf:Producer");
    const char *pdf_Keywords = xml.getChildContent("rdf:RDF|rdf:Description|pdf:Keywords");
    const char *xmpRights_WebStatement = xml.getChildContent("rdf:RDF|rdf:Description|xmpRights:WebStatement");
    }