"""PDF metadata stream generation.""" from uuid import uuid4 from xml.etree.ElementTree import Element, SubElement, register_namespace, tostring import pydyf from .. import __version__ # XML namespaces used for metadata NS = { 'rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#', 'dc': 'http://purl.org/dc/elements/1.1/', '': '', 'xmp': 'http://ns.adobe.com/xap/1.0/', 'xmpMM': 'http://ns.adobe.com/xap/1.0/mm/', 'pdf': 'http://ns.adobe.com/pdf/1.3/', 'pdfaid': 'http://www.aiim.org/pdfa/ns/id/', 'pdfuaid': 'http://www.aiim.org/pdfua/ns/id/', 'pdfxid': 'http://www.npes.org/pdfx/ns/id/', 'pdfx': 'http://ns.adobe.com/pdfx/1.3/', } for key, value in NS.items(): register_namespace(key, value) class DocumentMetadata: """Meta-information belonging to a whole :class:`Document`. New attributes may be added in future versions of WeasyPrint. """ def __init__(self, title=None, authors=None, description=None, keywords=None, generator=None, created=None, modified=None, attachments=None, lang=None, custom=None, xmp_metadata=None): #: The title of the document, as a string or :obj:`None`. #: Extracted from the ```` element in HTML #: and written to the ``/Title`` info field in PDF. self.title = title #: The authors of the document, as a list of strings. #: (Defaults to the empty list.) #: Extracted from the ``<meta name=author>`` elements in HTML #: and written to the ``/Author`` info field in PDF. self.authors = authors or [] #: The description of the document, as a string or :obj:`None`. #: Extracted from the ``<meta name=description>`` element in HTML #: and written to the ``/Subject`` info field in PDF. self.description = description #: Keywords associated with the document, as a list of strings. #: (Defaults to the empty list.) #: Extracted from ``<meta name=keywords>`` elements in HTML #: and written to the ``/Keywords`` info field in PDF. self.keywords = keywords or [] #: The name of one of the software packages #: used to generate the document, as a string or :obj:`None`. #: Extracted from the ``<meta name=generator>`` element in HTML #: and written to the ``/Creator`` info field in PDF. self.generator = generator #: The creation date of the document, as a string or :obj:`None`. #: Dates are in one of the six formats specified in #: `W3C’s profile of ISO 8601 <https://www.w3.org/TR/NOTE-datetime>`_. #: Extracted from the ``<meta name=dcterms.created>`` element in HTML #: and written to the ``/CreationDate`` info field in PDF. self.created = created #: The modification date of the document, as a string or :obj:`None`. #: Dates are in one of the six formats specified in #: `W3C’s profile of ISO 8601 <https://www.w3.org/TR/NOTE-datetime>`_. #: Extracted from the ``<meta name=dcterms.modified>`` element in HTML #: and written to the ``/ModDate`` info field in PDF. self.modified = modified #: A list of :class:`attachments <weasyprint.Attachment>`, empty by default. #: Extracted from the ``<link rel=attachment>`` elements in HTML #: and written to the ``/EmbeddedFiles`` dictionary in PDF. self.attachments = attachments or [] #: Document language as BCP 47 language tags. #: Extracted from ``<html lang=lang>`` in HTML. self.lang = lang #: Custom metadata, as a dict whose keys are the metadata names and #: values are the metadata values. self.custom = custom or {} #: A list of XML bytestrings to add into the XMP metadata. self.xmp_metadata = xmp_metadata or [] def include_in_pdf(self, pdf, variant, version, conformance, compress): """Add PDF stream of metadata. Described in ISO-32000-1:2008, 14.3.2. """ header = b'<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>\n' header += b'<x:xmpmeta xmlns:x="adobe:ns:meta/">' footer = b'</x:xmpmeta>\n<?xpacket end="r"?>' xml_data = self.generate_rdf_metadata(variant, version, conformance) stream_content = b'\n'.join((header, xml_data, *self.xmp_metadata, footer)) extra = {'Type': '/Metadata', 'Subtype': '/XML'} metadata = pydyf.Stream([stream_content], extra, compress) pdf.add_object(metadata) pdf.catalog['Metadata'] = metadata.reference def generate_rdf_metadata(self, variant, version, conformance): """Generate RDF metadata as a bytestring.""" namespace = f'pdf{variant}id' rdf = Element(f'{{{NS["rdf"]}}}RDF') if version: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element.attrib[f'{{{NS[namespace]}}}part'] = str(version) if conformance: assert version if variant == 'x': for key in ( f'{{{NS["pdfxid"]}}}GTS_PDFXVersion', f'{{{NS["pdfx"]}}}GTS_PDFXVersion', f'{{{NS["pdfx"]}}}GTS_PDFXConformance', ): subelement = SubElement(element, key) subelement.text = conformance subelement = SubElement(element, f'{{{NS["pdf"]}}}Trapped') subelement.text = 'False' if version >= 4: # TODO: these values could be useful instead of using random values. assert self.modified subelement = SubElement(element, f'{{{NS["xmp"]}}}MetadataDate') subelement.text = self.modified subelement = SubElement(element, f'{{{NS["xmpMM"]}}}DocumentID') subelement.text = f'xmp.did:{uuid4()}' subelement = SubElement(element, f'{{{NS["xmpMM"]}}}RenditionClass') subelement.text = 'proof:pdf' subelement = SubElement(element, f'{{{NS["xmpMM"]}}}VersionID') subelement.text = '1' else: element.attrib[f'{{{NS[namespace]}}}conformance'] = conformance if variant == 'a' and version == 4: subelement = SubElement(element, f'{{{NS["pdfaid"]}}}rev') subelement.text = '2020' element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element.attrib[f'{{{NS["pdf"]}}}Producer'] = f'WeasyPrint {__version__}' if self.title: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["dc"]}}}title') element = SubElement(element, f'{{{NS["rdf"]}}}Alt') element = SubElement(element, f'{{{NS["rdf"]}}}li') element.attrib['xml:lang'] = 'x-default' element.text = self.title if self.authors: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["dc"]}}}creator') element = SubElement(element, f'{{{NS["rdf"]}}}Seq') for author in self.authors: author_element = SubElement(element, f'{{{NS["rdf"]}}}li') author_element.text = author if self.description: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["dc"]}}}subject') element = SubElement(element, f'{{{NS["rdf"]}}}Bag') element = SubElement(element, f'{{{NS["rdf"]}}}li') element.attrib['xml:lang'] = 'x-default' element.text = self.description if self.keywords: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["pdf"]}}}Keywords') element.text = ', '.join(self.keywords) if self.generator: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["xmp"]}}}CreatorTool') element.text = self.generator if self.created: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["xmp"]}}}CreateDate') element.text = self.created if self.modified: element = SubElement(rdf, f'{{{NS["rdf"]}}}Description') element.attrib[f'{{{NS["rdf"]}}}about'] = '' element = SubElement(element, f'{{{NS["xmp"]}}}ModifyDate') element.text = self.modified return tostring(rdf, encoding='utf-8')