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Ruby

Extract Metadata XML from PDF

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Demonstrates how to extract the metadata XML from a PDF.

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Ruby 
require 'chilkat'

success = false

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

pdf = Chilkat::CkPdf.new()

success = pdf.LoadFile("qa_data/pdf/blank_with_metadata.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

sbXml = Chilkat::CkStringBuilder.new()
# Note: Not all PDF files have metadata.  Metadata is optional.
success = pdf.GetMetadata(sbXml)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

xml = Chilkat::CkXml.new()
xml.LoadSb(sbXml,true)

print xml.getXml() + "\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>

x_xmpmeta_xmlns_x = xml.getAttrValue("xmlns:x")
x_xmpmeta_x_xmptk = xml.getAttrValue("x:xmptk")
rdf_RDF_xmlns_rdf = xml.chilkatPath("rdf:RDF|(xmlns:rdf)")
rdf_Description_rdf_about = xml.chilkatPath("rdf:RDF|rdf:Description|(rdf:about)")
rdf_Description_xmlns_xmp = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:xmp)")
rdf_Description_xmlns_dc = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:dc)")
rdf_Description_xmlns_xmpMM = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:xmpMM)")
rdf_Description_xmlns_pdf = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:pdf)")
rdf_Description_xmlns_xmpRights = xml.chilkatPath("rdf:RDF|rdf:Description|(xmlns:xmpRights)")
xmp_ModifyDate = xml.getChildContent("rdf:RDF|rdf:Description|xmp:ModifyDate")
xmp_CreateDate = xml.getChildContent("rdf:RDF|rdf:Description|xmp:CreateDate")
xmp_MetadataDate = xml.getChildContent("rdf:RDF|rdf:Description|xmp:MetadataDate")
xmp_CreatorTool = xml.getChildContent("rdf:RDF|rdf:Description|xmp:CreatorTool")
dc_format = xml.getChildContent("rdf:RDF|rdf:Description|dc:format")
rdf_li_xml_lang = xml.chilkatPath("rdf:RDF|rdf:Description|dc:title|rdf:Alt|rdf:li|(xml:lang)")
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")
i = 0
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
end
xmpMM_DocumentID = xml.getChildContent("rdf:RDF|rdf:Description|xmpMM:DocumentID")
xmpMM_InstanceID = xml.getChildContent("rdf:RDF|rdf:Description|xmpMM:InstanceID")
pdf_Producer = xml.getChildContent("rdf:RDF|rdf:Description|pdf:Producer")
pdf_Keywords = xml.getChildContent("rdf:RDF|rdf:Description|pdf:Keywords")
xmpRights_WebStatement = xml.getChildContent("rdf:RDF|rdf:Description|xmpRights:WebStatement")