categories API

src/calibre/db/cache.py

@@ -401,6 +401,12 @@ class Cache(object):
     def get_item_name(self, field, item_id):
         return self.fields[field].table.id_map[item_id]
 
+    @read_api
+    def get_item_id(self, field, item_name):
+        ' Return the item id for item_name (case-insensitive) '
+        rmap = {icu_lower(v) if isinstance(v, unicode) else v:k for k, v in self.fields[field].table.id_map.iteritems()}
+        return rmap.get(icu_lower(item_name) if isinstance(item_name, unicode) else item_name, None)
+
     @read_api
     def author_data(self, author_ids=None):
         '''
@@ -1413,6 +1419,14 @@ class Cache(object):
     def set_custom_column_metadata(self, num, name=None, label=None, is_editable=None, display=None):
         return self.backend.set_custom_column_metadata(num, name=name, label=label, is_editable=is_editable, display=display)
 
+    @read_api
+    def get_books_for_category(self, category, item_id_or_composite_value):
+        f = self.fields[category]
+        if hasattr(f, 'get_books_for_val'):
+            # Composite field
+            return f.get_books_for_val(item_id_or_composite_value, self._get_metadata, self._all_book_ids())
+        return self._books_for_field(f.name, item_id_or_composite_value)
+
     # }}}
 
 class SortKey(object):  # {{{

src/calibre/db/fields.py

@@ -211,6 +211,16 @@ class CompositeField(OneToOneField):
             ans.append(c)
         return ans
 
+    def get_books_for_val(self, value, get_metadata, book_ids):
+        is_multiple = self.table.metadata['is_multiple'].get('cache_to_list', None)
+        ans = set()
+        for book_id in book_ids:
+            val = self.get_value_with_cache(book_id, get_metadata)
+            vals = {x.strip() for x in val.split(is_multiple)} if is_multiple else [val]
+            if value in vals:
+                ans.add(book_id)
+        return ans
+
 class OnDeviceField(OneToOneField):
 
     def __init__(self, name, table):

src/calibre/db/legacy.py

@@ -717,10 +717,13 @@ LibraryDatabase.format_hash = MT(lambda self, book_id, fmt:self.new_api.format_h
 LibraryDatabase.index = MT(lambda self, book_id, cache=False:self.data.id_to_index(book_id))
 LibraryDatabase.has_cover = MT(lambda self, book_id:self.new_api.field_for('cover', book_id))
 LibraryDatabase.get_tags = MT(lambda self, book_id:set(self.new_api.field_for('tags', book_id)))
+LibraryDatabase.get_categories = MT(lambda self, sort='name', ids=None, icon_map=None:self.new_api.get_categories(sort=sort, book_ids=ids, icon_map=icon_map))
 LibraryDatabase.get_identifiers = MT(
     lambda self, index, index_is_id=False: self.new_api.field_for('identifiers', index if index_is_id else self.id(index)))
 LibraryDatabase.isbn = MT(
     lambda self, index, index_is_id=False: self.get_identifiers(index, index_is_id=index_is_id).get('isbn', None))
+LibraryDatabase.get_books_for_category = MT(
+    lambda self, category, id_:self.new_api.get_books_for_category(category, id_))
 # }}}
 
 # Legacy setter API {{{

src/calibre/db/tests/legacy.py

@@ -161,10 +161,12 @@ class LegacyTest(BaseTest):
         from datetime import timedelta
         ndb = self.init_legacy(self.cloned_library)
         db = self.init_old()
+        newstag = ndb.new_api.get_item_id('tags', 'news')
 
         self.assertEqual(dict(db.prefs), dict(ndb.prefs))
 
         for meth, args in {
+            'get_books_for_category': [('tags', newstag), ('#formats', 'FMT1')],
             'get_next_series_num_for': [('A Series One',)],
             'get_id_from_uuid':[('ddddd',), (db.uuid(1, True),)],
             'cover':[(0,), (1,), (2,)],