import re
import datetime
import decimal
from generic import PdfObject
from xml.dom import getDOMImplementation
from xml.dom.minidom import parseString
RDF_NAMESPACE = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
DC_NAMESPACE = "http://purl.org/dc/elements/1.1/"
XMP_NAMESPACE = "http://ns.adobe.com/xap/1.0/"
PDF_NAMESPACE = "http://ns.adobe.com/pdf/1.3/"
XMPMM_NAMESPACE = "http://ns.adobe.com/xap/1.0/mm/"
# What is the PDFX namespace, you might ask? I might ask that too. It's
# a completely undocumented namespace used to place "custom metadata"
# properties, which are arbitrary metadata properties with no semantic or
# documented meaning. Elements in the namespace are key/value-style storage,
# where the element name is the key and the content is the value. The keys
# are transformed into valid XML identifiers by substituting an invalid
# identifier character with \u2182 followed by the unicode hex ID of the
# original character. A key like "my car" is therefore "my\u21820020car".
#
# \u2182, in case you're wondering, is the unicode character
# \u{ROMAN NUMERAL TEN THOUSAND}, a straightforward and obvious choice for
# escaping characters.
#
# Intentional users of the pdfx namespace should be shot on sight. A
# custom data schema and sensical XML elements could be used instead, as is
# suggested by Adobe's own documentation on XMP (under "Extensibility of
# Schemas").
#
# Information presented here on the /pdfx/ schema is a result of limited
# reverse engineering, and does not constitute a full specification.
PDFX_NAMESPACE = "http://ns.adobe.com/pdfx/1.3/"
iso8601 = re.compile("""
(?P<year>[0-9]{4})
(-
(?P<month>[0-9]{2})
(-
(?P<day>[0-9]+)
(T
(?P<hour>[0-9]{2}):
(?P<minute>[0-9]{2})
(:(?P<second>[0-9]{2}(.[0-9]+)?))?
(?P<tzd>Z|[-+][0-9]{2}:[0-9]{2})
)?
)?
)?
""", re.VERBOSE)
##
# An object that represents Adobe XMP metadata.
class XmpInformation(PdfObject):
def __init__(self, stream):
self.stream = stream
docRoot = parseString(self.stream.getData())
self.rdfRoot = docRoot.getElementsByTagNameNS(RDF_NAMESPACE, "RDF")[0]
self.cache = {}
def writeToStream(self, stream, encryption_key):
self.stream.writeToStream(stream, encryption_key)
def getElement(self, aboutUri, namespace, name):
for desc in self.rdfRoot.getElementsByTagNameNS(RDF_NAMESPACE, "Description"):
if desc.getAttributeNS(RDF_NAMESPACE, "about") == aboutUri:
attr = desc.getAttributeNodeNS(namespace, name)
if attr != None:
yield attr
for element in desc.getElementsByTagNameNS(namespace, name):
yield element
def getNodesInNamespace(self, aboutUri, namespace):
for desc in self.rdfRoot.getElementsByTagNameNS(RDF_NAMESPACE, "Description"):
if desc.getAttributeNS(RDF_NAMESPACE, "about") == aboutUri:
for i in range(desc.attributes.length):
attr = desc.attributes.item(i)
if attr.namespaceURI == namespace:
yield attr
for child in desc.childNodes:
if child.namespaceURI == namespace:
yield child
def _getText(self, element):
text = ""
for child in element.childNodes:
if child.nodeType == child.TEXT_NODE:
text += child.data
return text
def _converter_string(value):
return value
def _converter_date(value):
m = iso8601.match(value)
year = int(m.group("year"))
month = int(m.group("month") or "1")
day = int(m.group("day") or "1")
hour = int(m.group("hour") or "0")
minute = int(m.group("minute") or "0")
second = decimal.Decimal(m.group("second") or "0")
seconds = second.to_integral(decimal.ROUND_FLOOR)
milliseconds = (second - seconds) * 1000000
tzd = m.group("tzd") or "Z"
dt = datetime.datetime(year, month, day, hour, minute, seconds, milliseconds)
if tzd != "Z":
tzd_hours, tzd_minutes = [int(x) for x in tzd.split(":")]
tzd_hours *= -1
if tzd_hours < 0:
tzd_minutes *= -1
dt = dt + datetime.timedelta(hours=tzd_hours, minutes=tzd_minutes)
return dt
_test_converter_date = staticmethod(_converter_date)
def _getter_bag(namespace, name, converter):
def get(self):
cached = self.cache.get(namespace, {}).get(name)
if cached:
return cached
retval = []
for element in self.getElement("", namespace, name):
bags = element.getElementsByTagNameNS(RDF_NAMESPACE, "Bag")
if len(bags):
for bag in bags:
for item in bag.getElementsByTagNameNS(RDF_NAMESPACE, "li"):
value = self._getText(item)
value = converter(value)
retval.append(value)
ns_cache = self.cache.setdefault(namespace, {})
ns_cache[name] = retval
return retval
return get
def _getter_seq(namespace, name, converter):
def get(self):
cached = self.cache.get(namespace, {}).get(name)
if cached:
return cached
retval = []
for element in self.getElement("", namespace, name):
seqs = element.getElementsByTagNameNS(RDF_NAMESPACE, "Seq")
if len(seqs):
for seq in seqs:
for item in seq.getElementsByTagNameNS(RDF_NAMESPACE, "li"):
value = self._getText(item)
value = converter(value)
retval.append(value)
else:
value = converter(self._getText(element))
retval.append(value)
ns_cache = self.cache.setdefault(namespace, {})
ns_cache[name] = retval
return retval
return get
def _getter_langalt(namespace, name, converter):
def get(self):
cached = self.cache.get(namespace, {}).get(name)
if cached:
return cached
retval = {}
for element in self.getElement("", namespace, name):
alts = element.getElementsByTagNameNS(RDF_NAMESPACE, "Alt")
if len(alts):
for alt in alts:
for item in alt.getElementsByTagNameNS(RDF_NAMESPACE, "li"):
value = self._getText(item)
value = converter(value)
retval[item.getAttribute("xml:lang")] = value
else:
retval["x-default"] = converter(self._getText(element))
ns_cache = self.cache.setdefault(namespace, {})
ns_cache[name] = retval
return retval
return get
def _getter_single(namespace, name, converter):
def get(self):
cached = self.cache.get(namespace, {}).get(name)
if cached:
return cached
value = None
for element in self.getElement("", namespace, name):
if element.nodeType == element.ATTRIBUTE_NODE:
value = element.nodeValue
else:
value = self._getText(element)
break
if value != None:
value = converter(value)
ns_cache = self.cache.setdefault(namespace, {})
ns_cache[name] = value
return value
return get
##
# Contributors to the resource (other than the authors). An unsorted
# array of names.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_contributor = property(_getter_bag(DC_NAMESPACE, "contributor", _converter_string))
##
# Text describing the extent or scope of the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_coverage = property(_getter_single(DC_NAMESPACE, "coverage", _converter_string))
##
# A sorted array of names of the authors of the resource, listed in order
# of precedence.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_creator = property(_getter_seq(DC_NAMESPACE, "creator", _converter_string))
##
# A sorted array of dates (datetime.datetime instances) of signifigance to
# the resource. The dates and times are in UTC.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_date = property(_getter_seq(DC_NAMESPACE, "date", _converter_date))
##
# A language-keyed dictionary of textual descriptions of the content of the
# resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_description = property(_getter_langalt(DC_NAMESPACE, "description", _converter_string))
##
# The mime-type of the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_format = property(_getter_single(DC_NAMESPACE, "format", _converter_string))
##
# Unique identifier of the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_identifier = property(_getter_single(DC_NAMESPACE, "identifier", _converter_string))
##
# An unordered array specifying the languages used in the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_language = property(_getter_bag(DC_NAMESPACE, "language", _converter_string))
##
# An unordered array of publisher names.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_publisher = property(_getter_bag(DC_NAMESPACE, "publisher", _converter_string))
##
# An unordered array of text descriptions of relationships to other
# documents.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_relation = property(_getter_bag(DC_NAMESPACE, "relation", _converter_string))
##
# A language-keyed dictionary of textual descriptions of the rights the
# user has to this resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_rights = property(_getter_langalt(DC_NAMESPACE, "rights", _converter_string))
##
# Unique identifier of the work from which this resource was derived.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_source = property(_getter_single(DC_NAMESPACE, "source", _converter_string))
##
# An unordered array of descriptive phrases or keywrods that specify the
# topic of the content of the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_subject = property(_getter_bag(DC_NAMESPACE, "subject", _converter_string))
##
# A language-keyed dictionary of the title of the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_title = property(_getter_langalt(DC_NAMESPACE, "title", _converter_string))
##
# An unordered array of textual descriptions of the document type.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
dc_type = property(_getter_bag(DC_NAMESPACE, "type", _converter_string))
##
# An unformatted text string representing document keywords.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
pdf_keywords = property(_getter_single(PDF_NAMESPACE, "Keywords", _converter_string))
##
# The PDF file version, for example 1.0, 1.3.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
pdf_pdfversion = property(_getter_single(PDF_NAMESPACE, "PDFVersion", _converter_string))
##
# The name of the tool that created the PDF document.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
pdf_producer = property(_getter_single(PDF_NAMESPACE, "Producer", _converter_string))
##
# The date and time the resource was originally created. The date and
# time are returned as a UTC datetime.datetime object.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
xmp_createDate = property(_getter_single(XMP_NAMESPACE, "CreateDate", _converter_date))
##
# The date and time the resource was last modified. The date and time
# are returned as a UTC datetime.datetime object.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
xmp_modifyDate = property(_getter_single(XMP_NAMESPACE, "ModifyDate", _converter_date))
##
# The date and time that any metadata for this resource was last
# changed. The date and time are returned as a UTC datetime.datetime
# object.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
xmp_metadataDate = property(_getter_single(XMP_NAMESPACE, "MetadataDate", _converter_date))
##
# The name of the first known tool used to create the resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
xmp_creatorTool = property(_getter_single(XMP_NAMESPACE, "CreatorTool", _converter_string))
##
# The common identifier for all versions and renditions of this resource.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
xmpmm_documentId = property(_getter_single(XMPMM_NAMESPACE, "DocumentID", _converter_string))
##
# An identifier for a specific incarnation of a document, updated each
# time a file is saved.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
xmpmm_instanceId = property(_getter_single(XMPMM_NAMESPACE, "InstanceID", _converter_string))
def custom_properties(self):
if not hasattr(self, "_custom_properties"):
self._custom_properties = {}
for node in self.getNodesInNamespace("", PDFX_NAMESPACE):
key = node.localName
while True:
# see documentation about PDFX_NAMESPACE earlier in file
idx = key.find(u"\u2182")
if idx == -1:
break
key = key[:idx] + chr(int(key[idx+1:idx+5], base=16)) + key[idx+5:]
if node.nodeType == node.ATTRIBUTE_NODE:
value = node.nodeValue
else:
value = self._getText(node)
self._custom_properties[key] = value
return self._custom_properties
##
# Retrieves custom metadata properties defined in the undocumented pdfx
# metadata schema.
# <p>Stability: Added in v1.12, will exist for all future v1.x releases.
# @return Returns a dictionary of key/value items for custom metadata
# properties.
custom_properties = property(custom_properties)
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