(Delphi DLL) 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.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, StringBuilder, Pdf, Xml, CkDateTime;

...

procedure TForm1.Button1Click(Sender: TObject);
var
pdf: HCkPdf;
success: Boolean;
xml: HCkXml;
sbExisting: HCkStringBuilder;
hasMetadata: Boolean;
dt: HCkDateTime;
ts: PWideChar;
sbDocId: HCkStringBuilder;
sbInstanceId: HCkStringBuilder;
sb: HCkStringBuilder;

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

pdf := CkPdf_Create();

// Load a PDF file.
// If the PDF file already has metadata, we'll update it.
// Otherwise this example adds the metadata.
success := CkPdf_LoadFile(pdf,'qa_data/pdf/blank_with_metadata.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

xml := CkXml_Create();
sbExisting := CkStringBuilder_Create();

hasMetadata := CkPdf_GetMetadata(pdf,sbExisting);
if (hasMetadata = True) then
  begin
    CkXml_LoadSb(xml,sbExisting,True);
  end
else
  begin

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

    dt := CkDateTime_Create();
    CkDateTime_SetFromCurrentSystemTime(dt);
    ts := CkDateTime__getAsTimestamp(dt,True);

    CkXml_UpdateChildContent(xml,'rdf:RDF|rdf:Description|xmp:ModifyDate',ts);
    CkXml_UpdateChildContent(xml,'rdf:RDF|rdf:Description|xmp:CreateDate',ts);
    CkXml_UpdateChildContent(xml,'rdf:RDF|rdf:Description|xmp:MetadataDate',ts);

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

    sbDocId := CkStringBuilder_Create();
    CkStringBuilder_Append(sbDocId,'uuid:');
    CkStringBuilder_AppendUuid(sbDocId,True);
    CkXml_UpdateChildContent(xml,'rdf:RDF|rdf:Description|xmpMM:DocumentID',CkStringBuilder__getAsString(sbDocId));

    sbInstanceId := CkStringBuilder_Create();
    CkStringBuilder_Append(sbInstanceId,'uuid:');
    CkStringBuilder_AppendUuid(sbInstanceId,True);
    CkXml_UpdateChildContent(xml,'rdf:RDF|rdf:Description|xmpMM:InstanceID',CkStringBuilder__getAsString(sbInstanceId));

  end;

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

// Create a new PDF with the updated metadata.
sb := CkStringBuilder_Create();
CkXml_GetXmlSb(xml,sb);
success := CkPdf_UpdateMetadata(pdf,sb,'c:/temp/qa_output/out.pdf');
if (success = True) then
  begin
    Memo1.Lines.Add('Success');
  end
else
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
  end;

// 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.

Memo1.Lines.Add('OK');

CkPdf_Dispose(pdf);
CkXml_Dispose(xml);
CkStringBuilder_Dispose(sbExisting);
    CkDateTime_Dispose(dt);
    CkStringBuilder_Dispose(sbDocId);
    CkStringBuilder_Dispose(sbInstanceId);
CkStringBuilder_Dispose(sb);

end;