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 def as_bool(text):
 157     return text == 'true'
 158 as_bool.no_lang = True
 159
 160 def as_wluri_strict(text):
 161     return WLURI.strict(text)
 162
 163
 164 class Field(object):
 165     def __init__(self, uri, attr_name, validator=as_unicode, strict=None,
 166                  multiple=False, salias=None, **kwargs):
 167         self.uri = uri
 168         self.name = attr_name
 169         self.validator = validator
 170         self.strict = strict
 171         self.multiple = multiple
 172         self.salias = salias
 173
 174         self.required = (kwargs.get('required', True)
 175                          and 'default' not in kwargs)
 176         self.default = kwargs.get('default', [] if multiple else [None])
 177
 178     def validate_value(self, val, strict=False):
 179         if strict and self.strict is not None:
 180             validator = self.strict
 181         else:
 182             validator = self.validator
 183         try:
 184             if self.multiple:
 185                 if validator is None:
 186                     return val
 187                 new_values = []
 188                 for v in val:
 189                     nv = v
 190                     if v is not None:
 191                         nv = validator(v)
 192                         if hasattr(v, 'lang'):
 193                             setattr(nv, 'lang', v.lang)
 194                     new_values.append(nv)
 195                 return new_values
 196             elif len(val) > 1:
 197                 raise ValidationError(
 198                     "Multiple values not allowed for field '%s'" % self.uri
 199                 )
 200             elif len(val) == 0:
 201                 raise ValidationError(
 202                     "Field %s has no value to assign. Check your defaults."
 203                     % self.uri
 204                 )
 205             else:
 206                 if validator is None or val[0] is None:
 207                     return val[0]
 208                 nv = validator(val[0])
 209                 if hasattr(val[0], 'lang') and not hasattr(validator, 'no_lang'):
 210                     setattr(nv, 'lang', val[0].lang)
 211                 return nv
 212         except ValueError as e:
 213             raise ValidationError(
 214                 "Field '%s' - invald value: %s"
 215                 % (self.uri, e.message)
 216             )
 217
 218     def validate(self, fdict, fallbacks=None, strict=False, validate_required=True):
 219         if fallbacks is None:
 220             fallbacks = {}
 221         if self.uri not in fdict:
 222             if not self.required:
 223                 # Accept single value for single fields and saliases.
 224                 if self.name in fallbacks:
 225                     if self.multiple:
 226                         f = fallbacks[self.name]
 227                     else:
 228                         f = [fallbacks[self.name]]
 229                 elif self.salias and self.salias in fallbacks:
 230                     f = [fallbacks[self.salias]]
 231                 else:
 232                     f = self.default
 233             elif validate_required:
 234                 raise ValidationError("Required field %s not found" % self.uri)
 235             else:
 236                 return None
 237         else:
 238             f = fdict[self.uri]
 239
 240         return self.validate_value(f, strict=strict)
 241
 242     def __eq__(self, other):
 243         if isinstance(other, Field) and other.name == self.name:
 244             return True
 245         return False
 246
 247
 248 class DCInfo(type):
 249     def __new__(mcs, classname, bases, class_dict):
 250         fields = list(class_dict['FIELDS'])
 251
 252         for base in bases[::-1]:
 253             if hasattr(base, 'FIELDS'):
 254                 for field in base.FIELDS[::-1]:
 255                     try:
 256                         fields.index(field)
 257                     except ValueError:
 258                         fields.insert(0, field)
 259
 260         class_dict['FIELDS'] = tuple(fields)
 261         return super(DCInfo, mcs).__new__(mcs, classname, bases, class_dict)
 262
 263
 264 class WorkInfo(six.with_metaclass(DCInfo, object)):
 265     FIELDS = (
 266         Field(DCNS('creator'), 'authors', as_person, salias='author',
 267               multiple=True),
 268         Field(DCNS('title'), 'title'),
 269         Field(DCNS('type'), 'type', required=False, multiple=True),
 270
 271         Field(DCNS('contributor.editor'), 'editors',
 272               as_person, salias='editor', multiple=True, required=False),
 273         Field(DCNS('contributor.technical_editor'), 'technical_editors',
 274               as_person, salias='technical_editor', multiple=True,
 275               required=False),
 276         Field(DCNS('contributor.funding'), 'funders', salias='funder',
 277               multiple=True, required=False),
 278         Field(DCNS('contributor.thanks'), 'thanks', required=False),
 279
 280         Field(DCNS('date'), 'created_at'),
 281         Field(DCNS('date.pd'), 'released_to_public_domain_at', as_date,
 282               required=False),
 283         Field(DCNS('publisher'), 'publisher', multiple=True),
 284
 285         Field(DCNS('language'), 'language'),
 286         Field(DCNS('description'), 'description', required=False),
 287
 288         Field(DCNS('source'), 'source_name', required=False),
 289         Field(DCNS('source.URL'), 'source_urls', salias='source_url',
 290               multiple=True, required=False),
 291         Field(DCNS('identifier.url'), 'url', WLURI, strict=as_wluri_strict),
 292         Field(DCNS('rights.license'), 'license', required=False),
 293         Field(DCNS('rights'), 'license_description'),
 294
 295         Field(PLMETNS('digitisationSponsor'), 'sponsors', multiple=True,
 296               required=False),
 297         Field(WLNS('digitisationSponsorNote'), 'sponsor_note', required=False),
 298         Field(WLNS('contentWarning'), 'content_warnings', multiple=True,
 299               required=False),
 300         Field(WLNS('developmentStage'), 'stage', required=False),
 301     )
 302
 303     @classmethod
 304     def from_bytes(cls, xml, *args, **kwargs):
 305         return cls.from_file(six.BytesIO(xml), *args, **kwargs)
 306
 307     @classmethod
 308     def from_file(cls, xmlfile, *args, **kwargs):
 309         desc_tag = None
 310         try:
 311             iter = etree.iterparse(xmlfile, ['start', 'end'])
 312             for (event, element) in iter:
 313                 if element.tag == RDFNS('RDF') and event == 'start':
 314                     desc_tag = element
 315                     break
 316
 317             if desc_tag is None:
 318                 raise NoDublinCore("DublinCore section not found. \
 319                     Check if there are rdf:RDF and rdf:Description tags.")
 320
 321             # continue 'till the end of RDF section
 322             for (event, element) in iter:
 323                 if element.tag == RDFNS('RDF') and event == 'end':
 324                     break
 325
 326             # if there is no end, Expat should yell at us with an ExpatError
 327
 328             # extract data from the element and make the info
 329             return cls.from_element(desc_tag, *args, **kwargs)
 330         except XMLSyntaxError as e:
 331             raise ParseError(e)
 332         except ExpatError as e:
 333             raise ParseError(e)
 334
 335     @classmethod
 336     def from_element(cls, rdf_tag, *args, **kwargs):
 337         # The tree is already parsed,
 338         # so we don't need to worry about Expat errors.
 339         field_dict = {}
 340         desc = rdf_tag.find(".//" + RDFNS('Description'))
 341
 342         if desc is None:
 343             raise NoDublinCore(
 344                 "There must be a '%s' element inside the RDF."
 345                 % RDFNS('Description')
 346             )
 347
 348         lang = None
 349         p = desc
 350         while p is not None and lang is None:
 351             lang = p.attrib.get(XMLNS('lang'))
 352             p = p.getparent()
 353
 354         for e in desc.getchildren():
 355             fv = field_dict.get(e.tag, [])
 356             if e.text is not None:
 357                 text = e.text
 358                 if not isinstance(text, six.text_type):
 359                     text = text.decode('utf-8')
 360                 val = TextPlus(text)
 361                 val.lang = e.attrib.get(XMLNS('lang'), lang)
 362                 if e.tag == 'meta':
 363                     meta_id = e.attrib.get('id')
 364                     if meta_id and meta_id.endswith('-id'):
 365                         field_dict[meta_id] = [val.replace('ISBN-', 'ISBN ')]
 366             else:
 367                 val = e.text
 368             fv.append(val)
 369             field_dict[e.tag] = fv
 370
 371         return cls(desc.attrib, field_dict, *args, **kwargs)
 372
 373     def __init__(self, rdf_attrs, dc_fields, fallbacks=None, strict=False, validate_required=True):
 374         """
 375         rdf_attrs should be a dictionary-like object with any attributes
 376         of the RDF:Description.
 377         dc_fields - dictionary mapping DC fields (with namespace) to
 378         list of text values for the given field.
 379         """
 380
 381         self.about = rdf_attrs.get(RDFNS('about'))
 382         self.fmap = {}
 383
 384         for field in self.FIELDS:
 385             value = field.validate(dc_fields, fallbacks=fallbacks,
 386                                    strict=strict, validate_required=validate_required)
 387             setattr(self, 'prop_' + field.name, value)
 388             self.fmap[field.name] = field
 389             if field.salias:
 390                 self.fmap[field.salias] = field
 391
 392     def __getattribute__(self, name):
 393         try:
 394             field = object.__getattribute__(self, 'fmap')[name]
 395             value = object.__getattribute__(self, 'prop_'+field.name)
 396             if field.name == name:
 397                 return value
 398             else:  # singular alias
 399                 if not field.multiple:
 400                     raise "OUCH!! for field %s" % name
 401
 402                 return value[0] if value else None
 403         except (KeyError, AttributeError):
 404             return object.__getattribute__(self, name)
 405
 406     def __setattr__(self, name, newvalue):
 407         try:
 408             field = object.__getattribute__(self, 'fmap')[name]
 409             if field.name == name:
 410                 object.__setattr__(self, 'prop_'+field.name, newvalue)
 411             else:  # singular alias
 412                 if not field.multiple:
 413                     raise "OUCH! while setting field %s" % name
 414
 415                 object.__setattr__(self, 'prop_'+field.name, [newvalue])
 416         except (KeyError, AttributeError):
 417             return object.__setattr__(self, name, newvalue)
 418
 419     def update(self, field_dict):
 420         """
 421         Update using field_dict. Verify correctness, but don't check
 422         if all required fields are present.
 423         """
 424         for field in self.FIELDS:
 425             if field.name in field_dict:
 426                 setattr(self, field.name, field_dict[field.name])
 427
 428     def to_etree(self, parent=None):
 429         """XML representation of this object."""
 430         # etree._namespace_map[str(self.RDF)] = 'rdf'
 431         # etree._namespace_map[str(self.DC)] = 'dc'
 432
 433         if parent is None:
 434             root = etree.Element(RDFNS('RDF'))
 435         else:
 436             root = parent.makeelement(RDFNS('RDF'))
 437
 438         description = etree.SubElement(root, RDFNS('Description'))
 439
 440         if self.about:
 441             description.set(RDFNS('about'), self.about)
 442
 443         for field in self.FIELDS:
 444             v = getattr(self, field.name, None)
 445             if v is not None:
 446                 if field.multiple:
 447                     if len(v) == 0:
 448                         continue
 449                     for x in v:
 450                         e = etree.Element(field.uri)
 451                         if x is not None:
 452                             e.text = six.text_type(x)
 453                         description.append(e)
 454                 else:
 455                     e = etree.Element(field.uri)
 456                     e.text = six.text_type(v)
 457                     description.append(e)
 458
 459         return root
 460
 461     def serialize(self):
 462         rdf = {'about': {'uri': RDFNS('about'), 'value': self.about}}
 463
 464         dc = {}
 465         for field in self.FIELDS:
 466             v = getattr(self, field.name, None)
 467             if v is not None:
 468                 if field.multiple:
 469                     if len(v) == 0:
 470                         continue
 471                     v = [six.text_type(x) for x in v if x is not None]
 472                 else:
 473                     v = six.text_type(v)
 474
 475                 dc[field.name] = {'uri': field.uri, 'value': v}
 476         rdf['fields'] = dc
 477         return rdf
 478
 479     def to_dict(self):
 480         result = {'about': self.about}
 481         for field in self.FIELDS:
 482             v = getattr(self, field.name, None)
 483
 484             if v is not None:
 485                 if field.multiple:
 486                     if len(v) == 0:
 487                         continue
 488                     v = [six.text_type(x) for x in v if x is not None]
 489                 else:
 490                     v = six.text_type(v)
 491                 result[field.name] = v
 492
 493             if field.salias:
 494                 v = getattr(self, field.salias)
 495                 if v is not None:
 496                     result[field.salias] = six.text_type(v)
 497
 498         return result
 499
 500
 501 class BookInfo(WorkInfo):
 502     FIELDS = (
 503         Field(DCNS('audience'), 'audiences', salias='audience', multiple=True,
 504               required=False),
 505
 506         Field(DCNS('subject.period'), 'epochs', salias='epoch', multiple=True,
 507               required=False),
 508         Field(DCNS('subject.type'), 'kinds', salias='kind', multiple=True,
 509               required=False),
 510         Field(DCNS('subject.genre'), 'genres', salias='genre', multiple=True,
 511               required=False),
 512         Field(WLNS('category.legimi'), 'legimi', required=False),
 513
 514         Field(DCNS('subject.location'), 'location', required=False),
 515
 516         Field(DCNS('contributor.translator'), 'translators',
 517               as_person,  salias='translator', multiple=True, required=False),
 518         Field(DCNS('relation.hasPart'), 'parts', WLURI, strict=as_wluri_strict,
 519               multiple=True, required=False),
 520         Field(DCNS('relation.isVariantOf'), 'variant_of', WLURI,
 521               strict=as_wluri_strict, required=False),
 522
 523         Field(DCNS('relation.coverImage.url'), 'cover_url', required=False),
 524         Field(DCNS('relation.coverImage.attribution'), 'cover_by',
 525               required=False),
 526         Field(DCNS('relation.coverImage.source'), 'cover_source',
 527               required=False),
 528         # WLCover-specific.
 529         Field(WLNS('coverBarColor'), 'cover_bar_color', required=False),
 530         Field(WLNS('coverBoxPosition'), 'cover_box_position', required=False),
 531         Field(WLNS('coverClass'), 'cover_class', default=['default']),
 532         Field(WLNS('coverLogoUrl'), 'cover_logo_urls', multiple=True,
 533               required=False),
 534         Field(WLNS('endnotes'), 'endnotes', as_bool,
 535               required=False),
 536
 537         Field('pdf-id',  'isbn_pdf',  required=False),
 538         Field('epub-id', 'isbn_epub', required=False),
 539         Field('mobi-id', 'isbn_mobi', required=False),
 540         Field('txt-id',  'isbn_txt',  required=False),
 541         Field('html-id', 'isbn_html', required=False),
 542     )
 543
 544
 545 def parse(file_name, cls=BookInfo):
 546     return cls.from_file(file_name)