94 lines
3.8 KiB
Python
94 lines
3.8 KiB
Python
"""PDF metadata stream generation."""
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from xml.etree.ElementTree import (
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Element, SubElement, register_namespace, tostring)
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import pydyf
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from .. import __version__
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# XML namespaces used for metadata
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NS = {
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'rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
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'dc': 'http://purl.org/dc/elements/1.1/',
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'xmp': 'http://ns.adobe.com/xap/1.0/',
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'pdf': 'http://ns.adobe.com/pdf/1.3/',
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'pdfaid': 'http://www.aiim.org/pdfa/ns/id/',
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'pdfuaid': 'http://www.aiim.org/pdfua/ns/id/',
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}
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for key, value in NS.items():
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register_namespace(key, value)
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def add_metadata(pdf, metadata, variant, version, conformance, compress):
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"""Add PDF stream of metadata.
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Described in ISO-32000-1:2008, 14.3.2.
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"""
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# Add metadata
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namespace = f'pdf{variant}id'
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rdf = Element(f'{{{NS["rdf"]}}}RDF')
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element.attrib[f'{{{NS[namespace]}}}part'] = str(version)
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if conformance:
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element.attrib[f'{{{NS[namespace]}}}conformance'] = conformance
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element.attrib[f'{{{NS["pdf"]}}}Producer'] = f'WeasyPrint {__version__}'
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if metadata.title:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["dc"]}}}title')
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element = SubElement(element, f'{{{NS["rdf"]}}}Alt')
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element = SubElement(element, f'{{{NS["rdf"]}}}li')
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element.attrib['xml:lang'] = 'x-default'
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element.text = metadata.title
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if metadata.authors:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["dc"]}}}creator')
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element = SubElement(element, f'{{{NS["rdf"]}}}Seq')
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for author in metadata.authors:
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author_element = SubElement(element, f'{{{NS["rdf"]}}}li')
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author_element.text = author
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if metadata.description:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["dc"]}}}subject')
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element = SubElement(element, f'{{{NS["rdf"]}}}Bag')
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element = SubElement(element, f'{{{NS["rdf"]}}}li')
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element.text = metadata.description
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if metadata.keywords:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["pdf"]}}}Keywords')
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element.text = ', '.join(metadata.keywords)
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if metadata.generator:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["xmp"]}}}CreatorTool')
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element.text = metadata.generator
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if metadata.created:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["xmp"]}}}CreateDate')
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element.text = metadata.created
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if metadata.modified:
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element = SubElement(rdf, f'{{{NS["rdf"]}}}Description')
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element.attrib[f'{{{NS["rdf"]}}}about'] = ''
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element = SubElement(element, f'{{{NS["xmp"]}}}ModifyDate')
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element.text = metadata.modified
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xml = tostring(rdf, encoding='utf-8')
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header = b'<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>'
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footer = b'<?xpacket end="r"?>'
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stream_content = b'\n'.join((header, xml, footer))
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extra = {'Type': '/Metadata', 'Subtype': '/XML'}
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metadata = pydyf.Stream([stream_content], extra, compress)
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pdf.add_object(metadata)
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pdf.catalog['Metadata'] = metadata.reference
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