(Visual Basic 6.0) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

Dim pdf As New ChilkatPdf

' Load a PDF file.
' If the PDF file already has metadata, we'll update it.
' Otherwise this example adds the metadata.
Dim success As Long
success = pdf.LoadFile("qa_data/pdf/blank_with_metadata.pdf")
If (success = 0) Then
    Debug.Print pdf.LastErrorText
    Exit Sub
End If

Dim xml As New ChilkatXml
Dim sbExisting As New ChilkatStringBuilder

Dim hasMetadata As Long
hasMetadata = pdf.GetMetadata(sbExisting)
If (hasMetadata = 1) Then
    success = xml.LoadSb(sbExisting,1)
Else

    ' Otherwise create the bare minimum XMP metadata.
    xml.Tag = "x:xmpmeta"
    success = xml.AddAttribute("xmlns:x","adobe:ns:meta/")
    success = xml.AddAttribute("x:xmptk","Adobe XMP Core 9.1-c001 79.675d0f7, 2023/06/11-19:21:16 ")
    success = xml.UpdateAttrAt("rdf:RDF",1,"xmlns:rdf","http://www.w3.org/1999/02/22-rdf-syntax-ns#")
    success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"rdf:about","")
    success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"xmlns:xmp","http://ns.adobe.com/xap/1.0/")
    success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"xmlns:dc","http://purl.org/dc/elements/1.1/")
    success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"xmlns:xmpMM","http://ns.adobe.com/xap/1.0/mm/")
    success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"xmlns:pdf","http://ns.adobe.com/pdf/1.3/")
    success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"xmlns:xmpRights","http://ns.adobe.com/xap/1.0/rights/")

    Dim dt As New CkDateTime
    success = dt.SetFromCurrentSystemTime()
    Dim ts As String
    ts = dt.GetAsTimestamp(1)

    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"

    Dim sbDocId As New ChilkatStringBuilder
    success = sbDocId.Append("uuid:")
    success = sbDocId.AppendUuid(1)
    xml.UpdateChildContent "rdf:RDF|rdf:Description|xmpMM:DocumentID",sbDocId.GetAsString()

    Dim sbInstanceId As New ChilkatStringBuilder
    success = sbInstanceId.Append("uuid:")
    success = sbInstanceId.AppendUuid(1)
    xml.UpdateChildContent "rdf:RDF|rdf:Description|xmpMM:InstanceID",sbInstanceId.GetAsString()

End If

' Add our custom metadata tags to either the existing XML metdata, or the newly created metadata.
success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"xmlns:zf","urn:ferd:pdfa:CrossIndustryDocument:invoice:1p0#")
success = xml.UpdateAttrAt("rdf:RDF|rdf:Description",1,"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.
Dim sb As New ChilkatStringBuilder
success = xml.GetXmlSb(sb)
success = pdf.UpdateMetadata(sb,"c:/temp/qa_output/out.pdf")
If (success = 1) Then
    Debug.Print "Success"
Else
    Debug.Print pdf.LastErrorText
End If

' 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.

Debug.Print "OK"