Refactoring
[wolnelektury.git] / apps / oai / handlers.py
index 8b21f1c..59e599c 100644 (file)
@@ -3,31 +3,39 @@ from catalogue.models import Book, Tag
 from api.models import Deleted
 from api.handlers import WL_BASE
 from librarian.dcparser import BookInfo
+from librarian import WLURI
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.auth.models import User
 from datetime import datetime
 from lxml import etree
 from lxml.etree import ElementTree
 from django.db.models import Q
+from django.conf import settings
+from django.contrib.sites.models import Site
 
 
+WL_DC_READER_XPATH = '(.|*)/rdf:RDF/rdf:Description/%s/text()' 
 wl_dc_reader = metadata.MetadataReader(
     fields={
-    'title':       ('textList', 'rdf:RDF/rdf:Description/dc:title/text()'),
-    'creator':     ('textList', 'rdf:RDF/rdf:Description/dc:creator/text()'),
-    'subject':     ('textList', 'rdf:RDF/rdf:Description/dc:subject.period/text() | rdf:RDF/rdf:Description/dc:subject.type/text() | rdf:RDF/rdf:Description/dc:subject.genre/text()'),
-    'description': ('textList', 'rdf:RDF/rdf:Description/dc:description/text()'),
-    'publisher':   ('textList', 'rdf:RDF/rdf:Description/dc:publisher/text()'),
-    'contributor': ('textList', 'rdf:RDF/rdf:Description/dc:contributor.editor/text() | rdf:RDF/rdf:Description/dc:contributor.translator/text() | rdf:RDF/rdf:Description/dc:contributor.technical_editor/text()'),
-    'date':        ('textList', 'rdf:RDF/rdf:Description/dc:date/text()'),
-    'type':        ('textList', 'rdf:RDF/rdf:Description/dc:type/text()'),
-    'format':      ('textList', 'rdf:RDF/rdf:Description/dc:format/text()'),
-    'identifier':  ('textList', 'rdf:RDF/rdf:Description/dc:identifier.url/text()'),
-    'source':      ('textList', 'rdf:RDF/rdf:Description/dc:source/text()'),
-    'language':    ('textList', 'rdf:RDF/rdf:Description/dc:language/text()'),
+    'title':       ('textList', WL_DC_READER_XPATH % 'dc:title'),
+    'creator':     ('textList', WL_DC_READER_XPATH % 'dc:creator'),
+    'subject':     ('textList', (WL_DC_READER_XPATH + ' | ' + WL_DC_READER_XPATH + ' | ' + WL_DC_READER_XPATH) %
+                    ('dc:subject.period', 'dc:subject.type', 'dc:subject.genre')),
+    'description': ('textList', WL_DC_READER_XPATH % 'dc:description'),
+    'publisher':   ('textList', WL_DC_READER_XPATH % 'dc:publisher'),
+    'contributor': ('textList', (WL_DC_READER_XPATH + ' | ' + WL_DC_READER_XPATH + ' | ' + WL_DC_READER_XPATH) %
+                    ('dc:contributor.editor', 'dc:contributor.translator', 'dc:contributor.technical_editor')),
+    'date':        ('textList', WL_DC_READER_XPATH % 'dc:date'),
+    'type':        ('textList', WL_DC_READER_XPATH % 'dc:type'),
+    'format':      ('textList', WL_DC_READER_XPATH % 'dc:format'),
+    'identifier':  ('textList', WL_DC_READER_XPATH % 'dc:identifier.url'),
+    'source':      ('textList', WL_DC_READER_XPATH % 'dc:source'),
+    'language':    ('textList', WL_DC_READER_XPATH % 'dc:language'),
+    #'isPartOf':     ('textList', 'rdf:RDF/rdf:Description/dc:relation.isPartOf/text()'),
+    'hasPart':     ('textList', WL_DC_READER_XPATH % 'dc:relation.hasPart'),
     #    'relation':    ('textList', 'rdf:RDF/rdf:Description/dc:relation/text()'),
     #    'coverage':    ('textList', 'rdf:RDF/rdf:Description/dc:coverage/text()'),
-    'rights':      ('textList', 'rdf:RDF/rdf:Description/dc:rights/text()')
+    'rights':      ('textList', WL_DC_READER_XPATH % 'dc:rights')
     },
     namespaces={
     'dc': 'http://purl.org/dc/elements/1.1/',
@@ -35,11 +43,21 @@ wl_dc_reader = metadata.MetadataReader(
     )
 
 
+NS_DCTERMS = "http://purl.org/dc/terms/"
+
+
+def nsdcterms(name):
+    return '{%s}%s' % (NS_DCTERMS, name)
+
+
 class Catalogue(common.ResumptionOAIPMH):
     TAG_CATEGORIES = ['author', 'epoch', 'kind', 'genre']
-    
-    def __init__(self):
+
+    def __init__(self, metadata_registry):
         super(Catalogue, self).__init__()
+        self.metadata_registry = metadata_registry
+
+        self.oai_id = "oai:" + Site.objects.get_current().domain + ":%s"
 
         # earliest change
         year_zero = datetime(1990, 1, 1, 0, 0, 0)
@@ -51,62 +69,72 @@ class Catalogue(common.ResumptionOAIPMH):
 
         try:
             earliest_delete = \
-                Deleted.objects.ordery_by('deleted_at')[0].deleted_at
+                Deleted.objects.exclude(slug__exact=u'').ordery_by('deleted_at')[0].deleted_at
         except: earliest_delete = year_zero
 
         self.earliest_datestamp = earliest_change <= earliest_delete and \
             earliest_change or earliest_delete
 
-        # admins
-        self.admin_emails = [u.email for u in User.objects.filter(is_superuser=True)]
-
     def metadata(self, book):
-        xml = etree.parse(book.xml_file)
+        try:
+            xml = etree.parse(book.xml_file)
+        finally:
+            book.xml_file.close()
         md = wl_dc_reader(xml)
-        return md.getMap()
+        m = md.getMap()
+        if book.parent:
+            m['isPartOf'] = [str(WLURI.from_slug(book.parent.slug))]
+        return m
 
     def record_for_book(self, book, headers_only=False):
         meta = None
+        identifier = self.slug_to_identifier(book.slug)
         if isinstance(book, Book):
-            header = common.Header(book.slug, book.changed_at, [], False)
+            #            setSpec = map(self.tag_to_setspec, book.tags.filter(category__in=self.TAG_CATEGORIES))
+            header = common.Header(identifier, book.changed_at, [], False)
             if not headers_only:
                 meta = common.Metadata(self.metadata(book))
             about = None
         elif isinstance(book, Deleted):
-            header = common.Header(book.slug, book.deleted_at, [], True)
+            header = common.Header(identifier, book.deleted_at, [], True)
             if not headers_only:
                 meta = common.Metadata({})
             about = None
+        if headers_only:
+            return header
         return header, meta, about
 
     def identify(self, **kw):
         ident = common.Identify(
             'Wolne Lektury',  # generate
             '%s/oaipmh' % WL_BASE,  # generate
-            '1.1',  # version
-            self.admin_emails,  # adminEmails
+            '2.0',  # version
+            [m[1] for m in settings.MANAGERS],  # adminEmails
             self.earliest_datestamp,  # earliest datestamp of any change
             'persistent',  # deletedRecord
             'YYYY-MM-DDThh:mm:ssZ',  # granularity
-            'identity',  # compression
+            ['identity'],  # compression
             []  # descriptions
             )
         return ident
 
     def books(self, tag, from_, until):
         if tag:
-            books = Book.tagged.with_all([tag])
+            # we do not support sets, since they are problematic for deleted books.
+            raise error.NoSetHierarchyError("Wolne Lektury does not support sets.")
+            # books = Book.tagged.with_all([tag])
         else:
             books = Book.objects.all()
-        deleted = Deleted.objects.all()
+        deleted = Deleted.objects.exclude(slug__exact=u'')
 
         books = books.order_by('changed_at')
+        deleted = deleted.order_by('deleted_at')
         if from_:
             books = books.filter(changed_at__gte=from_)
             deleted = deleted.filter(deleted_at__gte=from_)
         if until:
             books = books.filter(changed_at__lte=until)
-            deleted = deleted.filter(deleted_at__gte=until)
+            deleted = deleted.filter(deleted_at__lte=until)
         return list(books) + list(deleted)
 
     @staticmethod
@@ -119,16 +147,16 @@ class Catalogue(common.ResumptionOAIPMH):
         cs = s.split(':')
         if len(cs) == 2:
             if not cs[0] in Catalogue.TAG_CATEGORIES:
-                raise error.NoSetHierarchyError()
+                raise error.NoSetHierarchyError("No category part in set")
             tag = Tag.objects.get(slug=cs[1], category=cs[0])
             return tag
-        raise error.NoSetHierarchyError()
+        raise error.NoSetHierarchyError("Setspec should have two components: category:slug")
 
     def getRecord(self, **kw):
         """
 Returns (header, metadata, about) for given record.
         """
-        slug = kw['record']
+        slug = self.identifier_to_slug(kw['identifier'])
         try:
             book = Book.objects.get(slug=slug)
             return self.record_for_book(book)
@@ -138,42 +166,70 @@ Returns (header, metadata, about) for given record.
                 deleted_book = Deleted.objects.get(content_type=book_type,
                                                   slug=slug)
             except:
-                raise error.NoRecordsMatchError()
+                raise error.IdDoesNotExistError("No item for this identifier")
             return self.record_for_book(deleted_book)
 
+    def validate_kw(self, kw):
+        if 'resumptionToken' in kw:
+            raise error.BadResumptionTokenError("No resumption token support at this point")
+        if 'metadataPrefix' in kw and not self.metadata_registry.hasWriter(kw['metadataPrefix']):
+            raise error.CannotDisseminateFormatError("This format is not supported")
+
+    def identifier_to_slug(self, ident):
+        return ident.split(':')[-1]
+
+    def slug_to_identifier(self, slug):
+        return self.oai_id % slug
+
     def listIdentifiers(self, **kw):
+        self.validate_kw(kw)
         records = [self.record_for_book(book, headers_only=True) for
-                   book in self.books(
-                       self.setspec_to_tag(
-                           kw.get('set', None)),
-                           kw.get('from', None),
+                   book in self.books(None,
+                           kw.get('from_', None),
                            kw.get('until', None))]
-        return records
+        return records, None
 
     def listRecords(self, **kw):
         """
 can get a resumptionToken kw.
 returns result, token
         """
+        self.validate_kw(kw)
         records = [self.record_for_book(book) for
-                   book in self.books(
-                       self.setspec_to_tag(
-                           kw.get('set', None)),
-                           kw.get('from', None),
+                   book in self.books(None,
+                           kw.get('from_', None),
                            kw.get('until', None))]
 
         return records, None
 
     def listMetadataFormats(self, **kw):
-        return [('oaidc',
-                 'http://www.openarchives.org/OAI/2.0/oai_dc.xsd',
-                 server.NS_OAIDC)]
+        formats = [
+            ('oai_dc',
+             'http://www.openarchives.org/OAI/2.0/oai_dc.xsd',
+             server.NS_OAIDC),
+            ('qdc',
+             'http://dublincore.org/schemas/xmls/qdc/2006/01/06/dcterms.xsd',
+             NS_DCTERMS)]
+        if 'identifier' in kw:
+            slug = self.identifier_to_slug(kw['identifier'])
+            try:
+                b = Book.objects.get(slug=slug)
+                return formats
+            except:
+                try:
+                    d = Deleted.objects.get(slug=slug)
+                    return []
+                except:
+                    raise error.IdDoesNotExistError("This id does not exist")
+        else:
+            return formats
 
     def listSets(self, **kw):
-        tags = []
-        for category in Catalogue.TAG_CATEGORIES:
-            for tag in Tag.objects.filter(category=category):
-                tags.append(("%s:%s" % (tag.category, tag.slug),
-                             tag.name,
-                             tag.description))
-        return tags
+        raise error.NoSetHierarchyError("Wolne Lektury does not support sets.")
+        # tags = []
+        # for category in Catalogue.TAG_CATEGORIES:
+        #     for tag in Tag.objects.filter(category=category):
+        #         tags.append(("%s:%s" % (tag.category, tag.slug),
+        #                      tag.name,
+        #                      tag.description))
+        # return tags, None