src/librarian/dcparser.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # This file is part of Librarian, licensed under GNU Affero GPLv3 or later.
   4 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   5 #
   6 from __future__ import unicode_literals
   7
   8 from xml.parsers.expat import ExpatError
   9 from datetime import date
  10 from functools import total_ordering
  11 import time
  12 import re
  13 import six
  14 from librarian.util import roman_to_int
  15
  16 from librarian import (ValidationError, NoDublinCore, ParseError, DCNS, RDFNS,
  17                        XMLNS, WLURI, WLNS, PLMETNS)
  18
  19 import lxml.etree as etree  # ElementTree API using libxml2
  20 from lxml.etree import XMLSyntaxError
  21
  22
  23 class TextPlus(six.text_type):
  24     pass
  25
  26
  27 class DatePlus(date):
  28     pass
  29
  30
  31 # ==============
  32 # = Converters =
  33 # ==============
  34 @six.python_2_unicode_compatible
  35 @total_ordering
  36 class Person(object):
  37     """Single person with last name and a list of first names."""
  38     def __init__(self, last_name, *first_names):
  39         self.last_name = last_name
  40         self.first_names = first_names
  41
  42     @classmethod
  43     def from_text(cls, text):
  44         parts = [token.strip() for token in text.split(',')]
  45         if len(parts) == 1:
  46             surname = parts[0]
  47             names = []
  48         elif len(parts) != 2:
  49             raise ValueError(
  50                 "Invalid person name. "
  51                 "There should be at most one comma: \"%s\"."
  52                 % text.encode('utf-8')
  53             )
  54         else:
  55             surname = parts[0]
  56             if len(parts[1]) == 0:
  57                 # there is no non-whitespace data after the comma
  58                 raise ValueError(
  59                     "Found a comma, but no names given: \"%s\" -> %r."
  60                     % (text, parts)
  61                 )
  62             names = parts[1].split()
  63         return cls(surname, *names)
  64
  65     def readable(self):
  66         return u" ".join(self.first_names + (self.last_name,))
  67
  68     def __eq__(self, right):
  69         return (self.last_name == right.last_name
  70                 and self.first_names == right.first_names)
  71
  72     def __lt__(self, other):
  73         return ((self.last_name, self.first_names)
  74                 < (other.last_name, other.first_names))
  75
  76     def __hash__(self):
  77         return hash((self.last_name, self.first_names))
  78
  79     def __str__(self):
  80         if len(self.first_names) > 0:
  81             return '%s, %s' % (self.last_name, ' '.join(self.first_names))
  82         else:
  83             return self.last_name
  84
  85     def __repr__(self):
  86         return 'Person(last_name=%r, first_names=*%r)' % (
  87             self.last_name, self.first_names
  88         )
  89
  90
  91 def as_date(text):
  92     """
  93     Dates for digitization of pictures. It seems we need the following:
  94     ranges:             '1350-1450',
  95     centuries:  "XVIII w.'
  96     half centuries/decades: '2 poł. XVIII w.', 'XVII w., l. 20'
  97     later-then: 'po 1450'
  98     circa 'ok. 1813-1814', 'ok.1876-ok.1886
  99     turn: 1893/1894
 100
 101     For now we will translate this to some single date
 102     losing information of course.
 103     """
 104     try:
 105         # check out the "N. poł X w." syntax
 106         if isinstance(text, six.binary_type):
 107             text = text.decode("utf-8")
 108
 109         century_format = (
 110             u"(?:([12]) *poł[.]? +)?([MCDXVI]+) *w[.,]*(?: *l[.]? *([0-9]+))?"
 111         )
 112         vague_format = u"(?:po *|ok. *)?([0-9]{4})(-[0-9]{2}-[0-9]{2})?"
 113
 114         m = re.match(century_format, text)
 115         m2 = re.match(vague_format, text)
 116         if m:
 117             half = m.group(1)
 118             decade = m.group(3)
 119             century = roman_to_int(m.group(2))
 120             if half is not None:
 121                 if decade is not None:
 122                     raise ValueError(
 123                         "Bad date format. "
 124                         "Cannot specify both half and decade of century."
 125                     )
 126                 half = int(half)
 127                 t = ((century*100 + (half-1)*50), 1, 1)
 128             else:
 129                 decade = int(decade or 0)
 130                 t = ((century*100 + decade), 1, 1)
 131         elif m2:
 132             year = m2.group(1)
 133             mon_day = m2.group(2)
 134             if mon_day:
 135                 t = time.strptime(year + mon_day, "%Y-%m-%d")
 136             else:
 137                 t = time.strptime(year, '%Y')
 138         else:
 139             raise ValueError
 140
 141         return DatePlus(t[0], t[1], t[2])
 142     except ValueError:
 143         raise ValueError("Unrecognized date format. Try YYYY-MM-DD or YYYY.")
 144
 145
 146 def as_person(text):
 147     return Person.from_text(text)
 148
 149
 150 def as_unicode(text):
 151     if isinstance(text, six.text_type):
 152         return text
 153     else:
 154         return TextPlus(text.decode('utf-8'))
 155
 156
 157 def as_wluri_strict(text):
 158     return WLURI.strict(text)
 159
 160
 161 class Field(object):
 162     def __init__(self, uri, attr_name, validator=as_unicode, strict=None,
 163                  multiple=False, salias=None, **kwargs):
 164         self.uri = uri
 165         self.name = attr_name
 166         self.validator = validator
 167         self.strict = strict
 168         self.multiple = multiple
 169         self.salias = salias
 170
 171         self.required = (kwargs.get('required', True)
 172                          and 'default' not in kwargs)
 173         self.default = kwargs.get('default', [] if multiple else [None])
 174
 175     def validate_value(self, val, strict=False):
 176         if strict and self.strict is not None:
 177             validator = self.strict
 178         else:
 179             validator = self.validator
 180         try:
 181             if self.multiple:
 182                 if validator is None:
 183                     return val
 184                 new_values = []
 185                 for v in val:
 186                     nv = v
 187                     if v is not None:
 188                         nv = validator(v)
 189                         if hasattr(v, 'lang'):
 190                             setattr(nv, 'lang', v.lang)
 191                     new_values.append(nv)
 192                 return new_values
 193             elif len(val) > 1:
 194                 raise ValidationError(
 195                     "Multiple values not allowed for field '%s'" % self.uri
 196                 )
 197             elif len(val) == 0:
 198                 raise ValidationError(
 199                     "Field %s has no value to assign. Check your defaults."
 200                     % self.uri
 201                 )
 202             else:
 203                 if validator is None or val[0] is None:
 204                     return val[0]
 205                 nv = validator(val[0])
 206                 if hasattr(val[0], 'lang'):
 207                     setattr(nv, 'lang', val[0].lang)
 208                 return nv
 209         except ValueError as e:
 210             raise ValidationError(
 211                 "Field '%s' - invald value: %s"
 212                 % (self.uri, e.message)
 213             )
 214
 215     def validate(self, fdict, fallbacks=None, strict=False, validate_required=True):
 216         if fallbacks is None:
 217             fallbacks = {}
 218         if self.uri not in fdict:
 219             if not self.required:
 220                 # Accept single value for single fields and saliases.
 221                 if self.name in fallbacks:
 222                     if self.multiple:
 223                         f = fallbacks[self.name]
 224                     else:
 225                         f = [fallbacks[self.name]]
 226                 elif self.salias and self.salias in fallbacks:
 227                     f = [fallbacks[self.salias]]
 228                 else:
 229                     f = self.default
 230             elif validate_required:
 231                 raise ValidationError("Required field %s not found" % self.uri)
 232             else:
 233                 return None
 234         else:
 235             f = fdict[self.uri]
 236
 237         return self.validate_value(f, strict=strict)
 238
 239     def __eq__(self, other):
 240         if isinstance(other, Field) and other.name == self.name:
 241             return True
 242         return False
 243
 244
 245 class DCInfo(type):
 246     def __new__(mcs, classname, bases, class_dict):
 247         fields = list(class_dict['FIELDS'])
 248
 249         for base in bases[::-1]:
 250             if hasattr(base, 'FIELDS'):
 251                 for field in base.FIELDS[::-1]:
 252                     try:
 253                         fields.index(field)
 254                     except ValueError:
 255                         fields.insert(0, field)
 256
 257         class_dict['FIELDS'] = tuple(fields)
 258         return super(DCInfo, mcs).__new__(mcs, classname, bases, class_dict)
 259
 260
 261 class WorkInfo(six.with_metaclass(DCInfo, object)):
 262     FIELDS = (
 263         Field(DCNS('creator'), 'authors', as_person, salias='author',
 264               multiple=True),
 265         Field(DCNS('title'), 'title'),
 266         Field(DCNS('type'), 'type', required=False, multiple=True),
 267
 268         Field(DCNS('contributor.editor'), 'editors',
 269               as_person, salias='editor', multiple=True, required=False),
 270         Field(DCNS('contributor.technical_editor'), 'technical_editors',
 271               as_person, salias='technical_editor', multiple=True,
 272               required=False),
 273         Field(DCNS('contributor.funding'), 'funders', salias='funder',
 274               multiple=True, required=False),
 275         Field(DCNS('contributor.thanks'), 'thanks', required=False),
 276
 277         Field(DCNS('date'), 'created_at'),
 278         Field(DCNS('date.pd'), 'released_to_public_domain_at', as_date,
 279               required=False),
 280         Field(DCNS('publisher'), 'publisher', multiple=True),
 281
 282         Field(DCNS('language'), 'language'),
 283         Field(DCNS('description'), 'description', required=False),
 284
 285         Field(DCNS('source'), 'source_name', required=False),
 286         Field(DCNS('source.URL'), 'source_urls', salias='source_url',
 287               multiple=True, required=False),
 288         Field(DCNS('identifier.url'), 'url', WLURI, strict=as_wluri_strict),
 289         Field(DCNS('rights.license'), 'license', required=False),
 290         Field(DCNS('rights'), 'license_description'),
 291
 292         Field(PLMETNS('digitisationSponsor'), 'sponsors', multiple=True,
 293               required=False),
 294         Field(WLNS('digitisationSponsorNote'), 'sponsor_note', required=False),
 295         Field(WLNS('contentWarning'), 'content_warnings', multiple=True,
 296               required=False),
 297         Field(WLNS('developmentStage'), 'stage', required=False),
 298     )
 299
 300     @classmethod
 301     def from_bytes(cls, xml, *args, **kwargs):
 302         return cls.from_file(six.BytesIO(xml), *args, **kwargs)
 303
 304     @classmethod
 305     def from_file(cls, xmlfile, *args, **kwargs):
 306         desc_tag = None
 307         try:
 308             iter = etree.iterparse(xmlfile, ['start', 'end'])
 309             for (event, element) in iter:
 310                 if element.tag == RDFNS('RDF') and event == 'start':
 311                     desc_tag = element
 312                     break
 313
 314             if desc_tag is None:
 315                 raise NoDublinCore("DublinCore section not found. \
 316                     Check if there are rdf:RDF and rdf:Description tags.")
 317
 318             # continue 'till the end of RDF section
 319             for (event, element) in iter:
 320                 if element.tag == RDFNS('RDF') and event == 'end':
 321                     break
 322
 323             # if there is no end, Expat should yell at us with an ExpatError
 324
 325             # extract data from the element and make the info
 326             return cls.from_element(desc_tag, *args, **kwargs)
 327         except XMLSyntaxError as e:
 328             raise ParseError(e)
 329         except ExpatError as e:
 330             raise ParseError(e)
 331
 332     @classmethod
 333     def from_element(cls, rdf_tag, *args, **kwargs):
 334         # The tree is already parsed,
 335         # so we don't need to worry about Expat errors.
 336         field_dict = {}
 337         desc = rdf_tag.find(".//" + RDFNS('Description'))
 338
 339         if desc is None:
 340             raise NoDublinCore(
 341                 "There must be a '%s' element inside the RDF."
 342                 % RDFNS('Description')
 343             )
 344
 345         lang = None
 346         p = desc
 347         while p is not None and lang is None:
 348             lang = p.attrib.get(XMLNS('lang'))
 349             p = p.getparent()
 350
 351         for e in desc.getchildren():
 352             fv = field_dict.get(e.tag, [])
 353             if e.text is not None:
 354                 text = e.text
 355                 if not isinstance(text, six.text_type):
 356                     text = text.decode('utf-8')
 357                 val = TextPlus(text)
 358                 val.lang = e.attrib.get(XMLNS('lang'), lang)
 359                 if e.tag == 'meta':
 360                     meta_id = e.attrib.get('id')
 361                     if meta_id and meta_id.endswith('-id'):
 362                         field_dict[meta_id] = [val.replace('ISBN-', 'ISBN ')]
 363             else:
 364                 val = e.text
 365             fv.append(val)
 366             field_dict[e.tag] = fv
 367
 368         return cls(desc.attrib, field_dict, *args, **kwargs)
 369
 370     def __init__(self, rdf_attrs, dc_fields, fallbacks=None, strict=False, validate_required=True):
 371         """
 372         rdf_attrs should be a dictionary-like object with any attributes
 373         of the RDF:Description.
 374         dc_fields - dictionary mapping DC fields (with namespace) to
 375         list of text values for the given field.
 376         """
 377
 378         self.about = rdf_attrs.get(RDFNS('about'))
 379         self.fmap = {}
 380
 381         for field in self.FIELDS:
 382             value = field.validate(dc_fields, fallbacks=fallbacks,
 383                                    strict=strict, validate_required=validate_required)
 384             setattr(self, 'prop_' + field.name, value)
 385             self.fmap[field.name] = field
 386             if field.salias:
 387                 self.fmap[field.salias] = field
 388
 389     def __getattribute__(self, name):
 390         try:
 391             field = object.__getattribute__(self, 'fmap')[name]
 392             value = object.__getattribute__(self, 'prop_'+field.name)
 393             if field.name == name:
 394                 return value
 395             else:  # singular alias
 396                 if not field.multiple:
 397                     raise "OUCH!! for field %s" % name
 398
 399                 return value[0] if value else None
 400         except (KeyError, AttributeError):
 401             return object.__getattribute__(self, name)
 402
 403     def __setattr__(self, name, newvalue):
 404         try:
 405             field = object.__getattribute__(self, 'fmap')[name]
 406             if field.name == name:
 407                 object.__setattr__(self, 'prop_'+field.name, newvalue)
 408             else:  # singular alias
 409                 if not field.multiple:
 410                     raise "OUCH! while setting field %s" % name
 411
 412                 object.__setattr__(self, 'prop_'+field.name, [newvalue])
 413         except (KeyError, AttributeError):
 414             return object.__setattr__(self, name, newvalue)
 415
 416     def update(self, field_dict):
 417         """
 418         Update using field_dict. Verify correctness, but don't check
 419         if all required fields are present.
 420         """
 421         for field in self.FIELDS:
 422             if field.name in field_dict:
 423                 setattr(self, field.name, field_dict[field.name])
 424
 425     def to_etree(self, parent=None):
 426         """XML representation of this object."""
 427         # etree._namespace_map[str(self.RDF)] = 'rdf'
 428         # etree._namespace_map[str(self.DC)] = 'dc'
 429
 430         if parent is None:
 431             root = etree.Element(RDFNS('RDF'))
 432         else:
 433             root = parent.makeelement(RDFNS('RDF'))
 434
 435         description = etree.SubElement(root, RDFNS('Description'))
 436
 437         if self.about:
 438             description.set(RDFNS('about'), self.about)
 439
 440         for field in self.FIELDS:
 441             v = getattr(self, field.name, None)
 442             if v is not None:
 443                 if field.multiple:
 444                     if len(v) == 0:
 445                         continue
 446                     for x in v:
 447                         e = etree.Element(field.uri)
 448                         if x is not None:
 449                             e.text = six.text_type(x)
 450                         description.append(e)
 451                 else:
 452                     e = etree.Element(field.uri)
 453                     e.text = six.text_type(v)
 454                     description.append(e)
 455
 456         return root
 457
 458     def serialize(self):
 459         rdf = {'about': {'uri': RDFNS('about'), 'value': self.about}}
 460
 461         dc = {}
 462         for field in self.FIELDS:
 463             v = getattr(self, field.name, None)
 464             if v is not None:
 465                 if field.multiple:
 466                     if len(v) == 0:
 467                         continue
 468                     v = [six.text_type(x) for x in v if x is not None]
 469                 else:
 470                     v = six.text_type(v)
 471
 472                 dc[field.name] = {'uri': field.uri, 'value': v}
 473         rdf['fields'] = dc
 474         return rdf
 475
 476     def to_dict(self):
 477         result = {'about': self.about}
 478         for field in self.FIELDS:
 479             v = getattr(self, field.name, None)
 480
 481             if v is not None:
 482                 if field.multiple:
 483                     if len(v) == 0:
 484                         continue
 485                     v = [six.text_type(x) for x in v if x is not None]
 486                 else:
 487                     v = six.text_type(v)
 488                 result[field.name] = v
 489
 490             if field.salias:
 491                 v = getattr(self, field.salias)
 492                 if v is not None:
 493                     result[field.salias] = six.text_type(v)
 494
 495         return result
 496
 497
 498 class BookInfo(WorkInfo):
 499     FIELDS = (
 500         Field(DCNS('audience'), 'audiences', salias='audience', multiple=True,
 501               required=False),
 502
 503         Field(DCNS('subject.period'), 'epochs', salias='epoch', multiple=True,
 504               required=False),
 505         Field(DCNS('subject.type'), 'kinds', salias='kind', multiple=True,
 506               required=False),
 507         Field(DCNS('subject.genre'), 'genres', salias='genre', multiple=True,
 508               required=False),
 509
 510         Field(DCNS('subject.location'), 'location', required=False),
 511
 512         Field(DCNS('contributor.translator'), 'translators',
 513               as_person,  salias='translator', multiple=True, required=False),
 514         Field(DCNS('relation.hasPart'), 'parts', WLURI, strict=as_wluri_strict,
 515               multiple=True, required=False),
 516         Field(DCNS('relation.isVariantOf'), 'variant_of', WLURI,
 517               strict=as_wluri_strict, required=False),
 518
 519         Field(DCNS('relation.coverImage.url'), 'cover_url', required=False),
 520         Field(DCNS('relation.coverImage.attribution'), 'cover_by',
 521               required=False),
 522         Field(DCNS('relation.coverImage.source'), 'cover_source',
 523               required=False),
 524         # WLCover-specific.
 525         Field(WLNS('coverBarColor'), 'cover_bar_color', required=False),
 526         Field(WLNS('coverBoxPosition'), 'cover_box_position', required=False),
 527         Field(WLNS('coverClass'), 'cover_class', default=['default']),
 528         Field(WLNS('coverLogoUrl'), 'cover_logo_urls', multiple=True,
 529               required=False),
 530
 531         Field('pdf-id',  'isbn_pdf',  required=False),
 532         Field('epub-id', 'isbn_epub', required=False),
 533         Field('mobi-id', 'isbn_mobi', required=False),
 534         Field('txt-id',  'isbn_txt',  required=False),
 535         Field('html-id', 'isbn_html', required=False),
 536     )
 537
 538
 539 def parse(file_name, cls=BookInfo):
 540     return cls.from_file(file_name)