X-Git-Url: https://git.mdrn.pl/librarian.git/blobdiff_plain/6642c1c71c5c6ce6ef3401c8c9da84cf076b018b..85b5bd4d4b6fdaff30df0dce136db850fe610830:/librarian/dcparser.py diff --git a/librarian/dcparser.py b/librarian/dcparser.py index 830b089..eddd8e5 100644 --- a/librarian/dcparser.py +++ b/librarian/dcparser.py @@ -1,9 +1,14 @@ # -*- coding: utf-8 -*- +# +# This file is part of Librarian, licensed under GNU Affero GPLv3 or later. +# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information. +# from xml.parsers.expat import ExpatError from datetime import date import time -from librarian import ValidationError, NoDublinCore +from librarian import (ValidationError, NoDublinCore, ParseError, DCNS, RDFNS, + WLURI) import lxml.etree as etree # ElementTree API using libxml2 from lxml.etree import XMLSyntaxError @@ -17,7 +22,7 @@ class Person(object): 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(',') ] @@ -33,17 +38,25 @@ class Person(object): 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 readable(self): + return u" ".join(self.first_names + (self.last_name,)) + def __eq__(self, right): return self.last_name == right.last_name and self.first_names == right.first_names - - + + def __cmp__(self, other): + return cmp((self.last_name, self.first_names), (other.last_name, other.first_names)) + + def __hash__(self): + return hash((self.last_name, self.first_names)) + def __unicode__(self): if len(self.first_names) > 0: 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) @@ -66,107 +79,125 @@ def as_unicode(text): else: return text.decode('utf-8') +def as_wluri_strict(text): + return WLURI.strict(text) + class Field(object): - def __init__(self, uri, attr_name, type=as_unicode, multiple=False, salias=None, **kwargs): + def __init__(self, uri, attr_name, validator=as_unicode, strict=None, multiple=False, salias=None, **kwargs): self.uri = uri self.name = attr_name - self.validator = type + self.validator = validator + self.strict = strict self.multiple = multiple self.salias = salias 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): + def validate_value(self, val, strict=False): + if strict and self.strict is not None: + validator = self.strict + else: + validator = self.validator try: if self.multiple: - if self.validator is None: + if validator is None: return val - return [ self.validator(v) if v is not None else v for v in val ] + return [ 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) + raise ValidationError("Multiple 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: + if validator is None or val[0] is None: return val[0] - return self.validator(val[0]) + return validator(val[0]) except ValueError, e: raise ValidationError("Field '%s' - invald value: %s" % (self.uri, e.message)) - def validate(self, fdict): + def validate(self, fdict, fallbacks=None, strict=False): + if fallbacks is None: + fallbacks = {} if not fdict.has_key(self.uri): if not self.required: - f = self.default + # Accept single value for single fields and saliases. + if self.name in fallbacks: + if self.multiple: + f = fallbacks[self.name] + else: + f = [fallbacks[self.name]] + elif self.salias and self.salias in fallbacks: + f = [fallbacks[self.salias]] + else: + f = self.default else: raise ValidationError("Required field %s not found" % self.uri) else: f = fdict[self.uri] - return self.validate_value(f) + return self.validate_value(f, strict=strict) -# ========== -# = Parser = -# ========== + def __eq__(self, other): + if isinstance(other, Field) and other.name == self.name: + return True + return False -class XMLNamespace(object): - '''Represents XML namespace.''' - - def __init__(self, uri): - self.uri = uri - def __call__(self, tag): - return '{%s}%s' % (self.uri, tag) +class DCInfo(type): + def __new__(meta, classname, bases, class_dict): + fields = list(class_dict['FIELDS']) - def __contains__(self, tag): - return tag.startswith(str(self)) + for base in bases[::-1]: + if hasattr(base, 'FIELDS'): + for field in base.FIELDS[::-1]: + try: + fields.index(field) + except ValueError: + fields.insert(0, field) - def __repr__(self): - return 'XMLNamespace(%r)' % self.uri - - def __str__(self): - return '%s' % self.uri + class_dict['FIELDS'] = tuple(fields) + return super(DCInfo, meta).__new__(meta, classname, bases, class_dict) -class BookInfo(object): - RDF = XMLNamespace('http://www.w3.org/1999/02/22-rdf-syntax-ns#') - DC = XMLNamespace('http://purl.org/dc/elements/1.1/') - +class WorkInfo(object): + __metaclass__ = DCInfo + 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', \ + Field( DCNS('creator'), 'authors', as_person, salias='author', multiple=True), + Field( DCNS('title'), 'title'), + Field( DCNS('type'), 'type', required=False, multiple=True), + + Field( DCNS('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', + Field( DCNS('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'), + + Field( DCNS('date'), 'created_at', as_date), + Field( DCNS('date.pd'), 'released_to_public_domain_at', as_date, required=False), + Field( DCNS('publisher'), 'publisher'), + + Field( DCNS('language'), 'language'), + Field( DCNS('description'), 'description', required=False), + + Field( DCNS('source'), 'source_name', required=False), + Field( DCNS('source.URL'), 'source_url', required=False), + Field( DCNS('identifier.url'), 'url', WLURI, strict=as_wluri_strict), + Field( DCNS('rights.license'), 'license', required=False), + Field( DCNS('rights'), 'license_description'), ) @classmethod - def from_string(cls, xml): + def from_string(cls, xml, *args, **kwargs): from StringIO import StringIO - return cls.from_file(StringIO(xml)) - + return cls.from_file(StringIO(xml), *args, **kwargs) + @classmethod - def from_file(cls, xmlfile): - desc_tag = None + def from_file(cls, xmlfile, *args, **kwargs): + desc_tag = None try: - iter = etree.iterparse(xmlfile, ['start', 'end']) + iter = etree.iterparse(xmlfile, ['start', 'end']) for (event, element) in iter: - if element.tag == cls.RDF('RDF') and event == 'start': + if element.tag == RDFNS('RDF') and event == 'start': desc_tag = element break @@ -176,24 +207,24 @@ class BookInfo(object): # continue 'till the end of RDF section for (event, element) in iter: - if element.tag == cls.RDF('RDF') and event == 'end': + if element.tag == RDFNS('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) + return cls.from_element(desc_tag, *args, **kwargs) except XMLSyntaxError, e: raise ParseError(e) except ExpatError, e: raise ParseError(e) @classmethod - def from_element(cls, rdf_tag): + def from_element(cls, rdf_tag, *args, **kwargs): # the tree is already parsed, so we don't need to worry about Expat errors field_dict = {} - desc = rdf_tag.find(".//" + cls.RDF('Description') ) - + desc = rdf_tag.find(".//" + RDFNS('Description')) + if desc is None: raise NoDublinCore("No DublinCore section found.") @@ -201,19 +232,20 @@ class BookInfo(object): 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): + return cls(desc.attrib, field_dict, *args, **kwargs) + + def __init__(self, rdf_attrs, dc_fields, fallbacks=None, strict=False): """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 + 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.about = rdf_attrs.get(RDFNS('about')) self.fmap = {} for field in self.FIELDS: - value = field.validate( dc_fields ) + value = field.validate(dc_fields, fallbacks=fallbacks, + strict=strict) setattr(self, 'prop_' + field.name, value) self.fmap[field.name] = field if field.salias: self.fmap[field.salias] = field @@ -227,8 +259,8 @@ class BookInfo(object): else: # singular alias if not field.multiple: raise "OUCH!! for field %s" % name - - return value[0] + + return value[0] if value else None except (KeyError, AttributeError): return object.__getattribute__(self, name) @@ -246,7 +278,7 @@ class BookInfo(object): return object.__setattr__(self, name, newvalue) def update(self, field_dict): - """Update using field_dict. Verify correctness, but don't check if all + """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): @@ -256,17 +288,17 @@ class BookInfo(object): """XML representation of this object.""" #etree._namespace_map[str(self.RDF)] = 'rdf' #etree._namespace_map[str(self.DC)] = 'dc' - + if parent is None: - root = etree.Element(self.RDF('RDF')) + root = etree.Element(RDFNS('RDF')) else: - root = parent.makeelement(self.RDF('RDF')) + root = parent.makeelement(RDFNS('RDF')) + + description = etree.SubElement(root, RDFNS('Description')) - description = etree.SubElement(root, self.RDF('Description')) - if self.about: - description.set(self.RDF('about'), self.about) - + description.set(RDFNS('about'), self.about) + for field in self.FIELDS: v = getattr(self, field.name, None) if v is not None: @@ -274,15 +306,34 @@ class BookInfo(object): if len(v) == 0: continue for x in v: e = etree.Element(field.uri) - e.text = unicode(x) + if x is not None: + e.text = unicode(x) description.append(e) else: e = etree.Element(field.uri) e.text = unicode(v) description.append(e) - + return root + def serialize(self): + rdf = {} + rdf['about'] = { 'uri': RDFNS('about'), 'value': self.about } + + dc = {} + 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 if x is not None ] + else: + v = unicode(v) + + dc[field.name] = {'uri': field.uri, 'value': v} + rdf['fields'] = dc + return rdf + def to_dict(self): result = {'about': self.about} for field in self.FIELDS: @@ -291,16 +342,42 @@ class BookInfo(object): if v is not None: if field.multiple: if len(v) == 0: continue - v = [ unicode(x) for x in v ] + v = [ unicode(x) for x in v if x is not None ] 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 - + if v is not None: result[field.salias] = unicode(v) + return result -def parse(file_name): - return BookInfo.from_file(file_name) + +class BookInfo(WorkInfo): + FIELDS = ( + Field( DCNS('audience'), 'audiences', salias='audience', multiple=True, + required=False), + + Field( DCNS('subject.period'), 'epochs', salias='epoch', multiple=True, + required=False), + Field( DCNS('subject.type'), 'kinds', salias='kind', multiple=True, + required=False), + Field( DCNS('subject.genre'), 'genres', salias='genre', multiple=True, + required=False), + + Field( DCNS('contributor.translator'), 'translators', \ + as_person, salias='translator', multiple=True, default=[]), + Field( DCNS('relation.hasPart'), 'parts', + WLURI, strict=as_wluri_strict, multiple=True, required=False), + Field( DCNS('relation.isVariantOf'), 'variant_of', + WLURI, strict=as_wluri_strict, required=False), + + Field( DCNS('relation.coverImage.url'), 'cover_url', required=False), + Field( DCNS('relation.coverImage.attribution'), 'cover_by', required=False), + Field( DCNS('relation.coverImage.source'), 'cover_source', required=False), + ) + + +def parse(file_name, cls=BookInfo): + return cls.from_file(file_name)