from datetime import date
import time
-# Import ElementTree from anywhere
-try:
- import xml.etree.ElementTree as etree # Python >= 2.5
-except ImportError:
- try:
- import elementtree.ElementTree as etree # effbot's pure Python module
- except ImportError:
- import lxml.etree as etree # ElementTree API using libxml2
+from librarian import ValidationError, NoDublinCore
+
+import lxml.etree as etree # ElementTree API using libxml2
+from lxml.etree import XMLSyntaxError
# ==============
def __init__(self, last_name, *first_names):
self.last_name = last_name
self.first_names = first_names
-
+
+ @classmethod
+ def from_text(cls, text):
+ parts = [ token.strip() for token in text.split(',') ]
+ if len(parts) == 1:
+ surname = parts[0]
+ names = []
+ elif len(parts) != 2:
+ raise ValueError("Invalid person name. There should be at most one comma: \"%s\"." % text)
+ else:
+ surname = parts[0]
+ if len(parts[1]) == 0:
+ # there is no non-whitespace data after the comma
+ raise ValueError("Found a comma, but no names given: \"%s\" -> %r." % (text, parts))
+ names = [ name for name in parts[1].split() if len(name) ] # all non-whitespace tokens
+ return cls(surname, *names)
def __eq__(self, right):
return self.last_name == right.last_name and self.first_names == right.first_names
return '%s, %s' % (self.last_name, ' '.join(self.first_names))
else:
return self.last_name
-
-
+
def __repr__(self):
return 'Person(last_name=%r, first_names=*%r)' % (self.last_name, self.first_names)
+def as_date(text):
+ try:
+ try:
+ t = time.strptime(text, '%Y-%m-%d')
+ except ValueError:
+ t = time.strptime(text, '%Y')
+ return date(t[0], t[1], t[2])
+ except ValueError, e:
+ raise ValueError("Unrecognized date format. Try YYYY-MM-DD or YYYY.")
-def str_to_unicode(value, previous):
- return unicode(value)
-
+def as_person(text):
+ return Person.from_text(text)
-def str_to_unicode_list(value, previous):
- if previous is None:
- previous = []
- previous.append(str_to_unicode(value, None))
- return previous
+def as_unicode(text):
+ if isinstance(text, unicode):
+ return text
+ else:
+ return text.decode('utf-8')
+class Field(object):
+ def __init__(self, uri, attr_name, type=as_unicode, multiple=False, salias=None, **kwargs):
+ self.uri = uri
+ self.name = attr_name
+ self.validator = type
+ self.multiple = multiple
+ self.salias = salias
-def str_to_person(value, previous):
- comma_count = value.count(',')
-
- if comma_count == 0:
- last_name, first_names = value, []
- elif comma_count == 1:
- last_name, first_names = value.split(',')
- first_names = [name for name in first_names.split(' ') if len(name)]
- else:
- raise ValueError("value contains more than one comma: %r" % value)
-
- return Person(last_name.strip(), *first_names)
+ self.required = kwargs.get('required', True) and not kwargs.has_key('default')
+ self.default = kwargs.get('default', [] if multiple else [None])
+ def validate_value(self, val):
+ try:
+ if self.multiple:
+ if self.validator is None:
+ return val
+ return [ self.validator(v) if v is not None else v for v in val ]
+ elif len(val) > 1:
+ raise ValidationError("Mulitply values not allowed for field '%s'" % self.uri)
+ elif len(val) == 0:
+ raise ValidationError("Field %s has no value to assign. Check your defaults." % self.uri)
+ else:
+ if self.validator is None or val[0] is None:
+ return val[0]
+ return self.validator(val[0])
+ except ValueError, e:
+ raise ValidationError("Field '%s' - invald value: %s" % (self.uri, e.message))
-def str_to_date(value, previous):
- try:
- t = time.strptime(value, '%Y-%m-%d')
- except ValueError:
- t = time.strptime(value, '%Y')
- return date(t[0], t[1], t[2])
+ def validate(self, fdict):
+ if not fdict.has_key(self.uri):
+ if not self.required:
+ f = self.default
+ else:
+ raise ValidationError("Required field %s not found" % self.uri)
+ else:
+ f = fdict[self.uri]
+ return self.validate_value(f)
# ==========
# = Parser =
# ==========
-class ParseError(Exception):
- def __init__(self, message):
- super(ParseError, self).__init__(message)
-
class XMLNamespace(object):
'''Represents XML namespace.'''
RDF = XMLNamespace('http://www.w3.org/1999/02/22-rdf-syntax-ns#')
DC = XMLNamespace('http://purl.org/dc/elements/1.1/')
- mapping = {
- DC('creator') : ('author', str_to_person),
- DC('title') : ('title', str_to_unicode),
- DC('subject.period') : ('epoch', str_to_unicode),
- DC('subject.type') : ('kind', str_to_unicode),
- DC('subject.genre') : ('genre', str_to_unicode),
- DC('date') : ('created_at', str_to_date),
- DC('date.pd') : ('released_to_public_domain_at', str_to_date),
- DC('contributor.translator') : ('translator', str_to_person),
- DC('contributor.technical_editor') : ('technical_editor', str_to_person),
- DC('publisher') : ('publisher', str_to_unicode),
- DC('source') : ('source_name', str_to_unicode),
- DC('source.URL') : ('source_url', str_to_unicode),
- DC('identifier.url') : ('url', str_to_unicode),
- DC('relation.hasPart') : ('parts', str_to_unicode_list),
- DC('rights.license') : ('license', str_to_unicode),
- DC('rights') : ('license_description', str_to_unicode),
- }
+ FIELDS = (
+ Field( DC('creator'), 'author', as_person),
+ Field( DC('title'), 'title'),
+ Field( DC('subject.period'), 'epoches', salias='epoch', multiple=True),
+ Field( DC('subject.type'), 'kinds', salias='kind', multiple=True),
+ Field( DC('subject.genre'), 'genres', salias='genre', multiple=True),
+ Field( DC('date'), 'created_at', as_date),
+ Field( DC('date.pd'), 'released_to_public_domain_at', as_date, required=False),
+ Field( DC('contributor.editor'), 'editors', \
+ as_person, salias='editor', multiple=True, default=[]),
+ Field( DC('contributor.translator'), 'translators', \
+ as_person, salias='translator', multiple=True, default=[]),
+ Field( DC('contributor.technical_editor'), 'technical_editors',
+ as_person, salias='technical_editor', multiple=True, default=[]),
+ Field( DC('publisher'), 'publisher'),
+ Field( DC('source'), 'source_name', required=False),
+ Field( DC('source.URL'), 'source_url', required=False),
+ Field( DC('identifier.url'), 'url'),
+ Field( DC('relation.hasPart'), 'parts', multiple=True, required=False),
+ Field( DC('rights.license'), 'license', required=False),
+ Field( DC('rights'), 'license_description'),
+ )
@classmethod
def from_string(cls, xml):
from StringIO import StringIO
return cls.from_file(StringIO(xml))
-
+
@classmethod
- def from_file(cls, xml_file):
- book_info = cls()
-
+ def from_file(cls, xmlfile):
+ desc_tag = None
try:
- tree = etree.parse(xml_file)
+ iter = etree.iterparse(xmlfile, ['start', 'end'])
+ for (event, element) in iter:
+ if element.tag == cls.RDF('RDF') and event == 'start':
+ desc_tag = element
+ break
+
+ if desc_tag is None:
+ raise NoDublinCore("DublinCore section not found. \
+ Check if there are rdf:RDF and rdf:Description tags.")
+
+ # continue 'till the end of RDF section
+ for (event, element) in iter:
+ if element.tag == cls.RDF('RDF') and event == 'end':
+ break
+
+ # if there is no end, Expat should yell at us with an ExpatError
+
+ # extract data from the element and make the info
+ return cls.from_element(desc_tag)
+ except XMLSyntaxError, e:
+ raise ParseError(e)
except ExpatError, e:
raise ParseError(e)
- description = tree.find('//' + book_info.RDF('Description'))
- book_info.wiki_url = description.get(cls.RDF('about'), None)
-
- if description is None:
- raise ParseError('no Description tag found in document')
-
- for element in description.findall('*'):
- book_info.parse_element(element)
+ @classmethod
+ def from_element(cls, rdf_tag):
+ # the tree is already parsed, so we don't need to worry about Expat errors
+ field_dict = {}
+ desc = rdf_tag.find(".//" + cls.RDF('Description') )
- return book_info
+ if desc is None:
+ raise NoDublinCore("No DublinCore section found.")
+
+ for e in desc.getchildren():
+ fv = field_dict.get(e.tag, [])
+ fv.append(e.text)
+ field_dict[e.tag] = fv
+
+ return cls( desc.attrib, field_dict )
+
+ def __init__(self, rdf_attrs, dc_fields):
+ """rdf_attrs should be a dictionary-like object with any attributes of the RDF:Description.
+ dc_fields - dictionary mapping DC fields (with namespace) to list of text values for the
+ given field. """
+
+ self.about = rdf_attrs.get(self.RDF('about'))
+ self.fmap = {}
+
+ for field in self.FIELDS:
+ value = field.validate( dc_fields )
+ setattr(self, 'prop_' + field.name, value)
+ self.fmap[field.name] = field
+ if field.salias: self.fmap[field.salias] = field
+
+ def __getattribute__(self, name):
+ try:
+ field = object.__getattribute__(self, 'fmap')[name]
+ value = object.__getattribute__(self, 'prop_'+field.name)
+ if field.name == name:
+ return value
+ else: # singular alias
+ if not field.multiple:
+ raise "OUCH!! for field %s" % name
+
+ return value[0]
+ except (KeyError, AttributeError):
+ return object.__getattribute__(self, name)
- def parse_element(self, element):
+ def __setattr__(self, name, newvalue):
try:
- attribute, converter = self.mapping[element.tag]
- setattr(self, attribute, converter(element.text, getattr(self, attribute, None)))
- except KeyError:
- pass
+ field = object.__getattribute__(self, 'fmap')[name]
+ if field.name == name:
+ object.__setattr__(self, 'prop_'+field.name, newvalue)
+ else: # singular alias
+ if not field.multiple:
+ raise "OUCH! while setting field %s" % name
- def to_xml(self):
+ object.__setattr__(self, 'prop_'+field.name, [newvalue])
+ except (KeyError, AttributeError):
+ return object.__setattr__(self, name, newvalue)
+
+ def update(self, field_dict):
+ """Update using field_dict. Verify correctness, but don't check if all
+ required fields are present."""
+ for field in self.FIELDS:
+ if field_dict.has_key(field.name):
+ setattr(self, field.name, field_dict[field.name])
+
+ def to_etree(self, parent = None):
"""XML representation of this object."""
- etree._namespace_map[str(self.RDF)] = 'rdf'
- etree._namespace_map[str(self.DC)] = 'dc'
+ #etree._namespace_map[str(self.RDF)] = 'rdf'
+ #etree._namespace_map[str(self.DC)] = 'dc'
- root = etree.Element(self.RDF('RDF'))
+ if parent is None:
+ root = etree.Element(self.RDF('RDF'))
+ else:
+ root = parent.makeelement(self.RDF('RDF'))
+
description = etree.SubElement(root, self.RDF('Description'))
- if self.wiki_url:
- description.set(self.RDF('about'), self.wiki_url)
+ if self.about:
+ description.set(self.RDF('about'), self.about)
- for tag, (attribute, converter) in self.mapping.iteritems():
- if hasattr(self, attribute):
- e = etree.Element(tag)
- e.text = unicode(getattr(self, attribute))
- description.append(e)
+ for field in self.FIELDS:
+ v = getattr(self, field.name, None)
+ if v is not None:
+ if field.multiple:
+ if len(v) == 0: continue
+ for x in v:
+ e = etree.Element(field.uri)
+ e.text = unicode(x)
+ description.append(e)
+ else:
+ e = etree.Element(field.uri)
+ e.text = unicode(v)
+ description.append(e)
- return unicode(etree.tostring(root, 'utf-8'), 'utf-8')
+ return root
def to_dict(self):
- etree._namespace_map[str(self.RDF)] = 'rdf'
- etree._namespace_map[str(self.DC)] = 'dc'
-
- result = {'about': self.wiki_url}
- for tag, (attribute, converter) in self.mapping.iteritems():
- if hasattr(self, attribute):
- result[attribute] = unicode(getattr(self, attribute))
+ result = {'about': self.about}
+ for field in self.FIELDS:
+ v = getattr(self, field.name, None)
+
+ if v is not None:
+ if field.multiple:
+ if len(v) == 0: continue
+ v = [ unicode(x) for x in v ]
+ else:
+ v = unicode(v)
+ result[field.name] = v
+
+ if field.salias:
+ v = getattr(self, field.salias)
+ if v is not None: result[field.salias] = v
return result
-
def parse(file_name):
return BookInfo.from_file(file_name)
-
-
-if __name__ == '__main__':
- import sys
-
- info = parse(sys.argv[1])
- for attribute, _ in BookInfo.mapping.values():
- print '%s: %r' % (attribute, getattr(info, attribute, None))
-
fnp / librarian.git / blobdiff