New metadata:

1) remove 'category' from standard metadata fields
2) make isbn a classifier. Add ability to add more classifiers
3) fixup TODO: to make them easier to find.

src/calibre/devices/usbms/books.py

@@ -135,6 +135,7 @@ class CollectionsBookList(BookList):
                 elif isinstance(val, unicode):
                     val = [val]
                 for category in val:
+                    # TODO: NEWMETA: format the custom fields
                     if attr == 'tags' and len(category) > 1 and \
                             category[0] == '[' and category[-1] == ']':
                         continue

src/calibre/ebooks/metadata/book/__init__.py

@@ -19,8 +19,14 @@ SOCIAL_METADATA_FIELDS = frozenset([
     # Of the form { scheme1:value1, scheme2:value2}
     # For example: {'isbn':'123456789', 'doi':'xxxx', ... }
     'classifiers',
-    'isbn',     # Pseudo field for convenience, should get/set isbn classifier
-    'category', # TODO: not sure what this is, but it is used by OPF
+])
+
+'''
+The list of names that convert to classifiers when in get and set.
+'''
+
+TOP_LEVEL_CLASSIFIERS = frozenset([
+    'isbn',
 ])
 
 PUBLICATION_METADATA_FIELDS = frozenset([
@@ -77,7 +83,7 @@ CALIBRE_METADATA_FIELDS = frozenset([
     'application_id',   # An application id, currently set to the db_id.
     # the calibre primary key of the item.
     'db_id',            # the calibre primary key of the item.
-                        # TODO: May want to remove once Sony's no longer use it
+                        # TODO: NEWMETA: May want to remove once Sony's no longer use it
     ]
 )
 

src/calibre/ebooks/metadata/book/base.py

@@ -11,6 +11,7 @@ import traceback
 from calibre import prints
 from calibre.ebooks.metadata.book import COPYABLE_METADATA_FIELDS
 from calibre.ebooks.metadata.book import STANDARD_METADATA_FIELDS
+from calibre.ebooks.metadata.book import TOP_LEVEL_CLASSIFIERS
 from calibre.utils.date import isoformat
 
 
@@ -55,6 +56,8 @@ class Metadata(object):
 
     def __getattribute__(self, field):
         _data = object.__getattribute__(self, '_data')
+        if field in TOP_LEVEL_CLASSIFIERS:
+            return _data.get('classifiers').get(field, None)
         if field in STANDARD_METADATA_FIELDS:
             return _data.get(field, None)
         try:
@@ -68,7 +71,9 @@ class Metadata(object):
 
     def __setattr__(self, field, val, extra=None):
         _data = object.__getattribute__(self, '_data')
-        if field in STANDARD_METADATA_FIELDS:
+        if field in TOP_LEVEL_CLASSIFIERS:
+            _data['classifiers'].update({field: val})
+        elif field in STANDARD_METADATA_FIELDS:
             if val is None:
                 val = NULL_VALUES.get(field, None)
             _data[field] = val
@@ -301,8 +306,6 @@ class Metadata(object):
             fmt('Publisher', self.publisher)
         if getattr(self, 'book_producer', False):
             fmt('Book Producer', self.book_producer)
-        if self.category:
-            fmt('Category', self.category)
         if self.comments:
             fmt('Comments', self.comments)
         if self.isbn:
@@ -321,14 +324,7 @@ class Metadata(object):
             fmt('Published', isoformat(self.pubdate))
         if self.rights is not None:
             fmt('Rights', unicode(self.rights))
-#        TODO: These are not in metadata. Should they be?
-#        if self.lccn:
-#            fmt('LCCN', unicode(self.lccn))
-#        if self.lcc:
-#            fmt('LCC', unicode(self.lcc))
-#        if self.ddc:
-#            fmt('DDC', unicode(self.ddc))
-        # CUSTFIELD: What to do about custom fields?
+        # TODO: NEWMETA: What to do about custom fields?
         return u'\n'.join(ans)
 
     def to_html(self):
@@ -339,13 +335,6 @@ class Metadata(object):
         ans += [(_('Producer'), unicode(self.book_producer))]
         ans += [(_('Comments'), unicode(self.comments))]
         ans += [('ISBN', unicode(self.isbn))]
-#        TODO: These are not in metadata. Should they be?
-#        if self.lccn:
-#            ans += [('LCCN', unicode(self.lccn))]
-#        if self.lcc:
-#            ans += [('LCC', unicode(self.lcc))]
-#        if self.ddc:
-#            ans += [('DDC', unicode(self.ddc))]
         ans += [(_('Tags'), u', '.join([unicode(t) for t in self.tags]))]
         if self.series:
             ans += [(_('Series'), unicode(self.series)+ ' #%s'%self.format_series_index())]

src/calibre/ebooks/metadata/opf2.py

@@ -1188,7 +1188,7 @@ def metadata_to_opf(mi, as_string=True):
     factory(DC('contributor'), mi.book_producer, __appname__, 'bkp')
     if hasattr(mi.pubdate, 'isoformat'):
         factory(DC('date'), isoformat(mi.pubdate))
-    if mi.category:
+    if hasattr(mi, 'category') and mi.category:
         factory(DC('type'), mi.category)
     if mi.comments:
         factory(DC('description'), mi.comments)

src/calibre/gui2/dialogs/config/save_template.py

@@ -34,8 +34,8 @@ class SaveTemplate(QWidget, Ui_Form):
         self.option_name = name
 
     def validate(self):
-        # TODO: I haven't figured out how to get the custom columns into here,
-        # so for the moment make all templates valid.
+        # TODO: NEWMETA: I haven't figured out how to get the custom columns
+        # into here, so for the moment make all templates valid.
         return True
 #        tmpl = preprocess_template(self.opt_template.text())
 #        fa = {}

src/calibre/library/save_to_disk.py

@@ -131,7 +131,7 @@ def get_components(template, mi, id, timefmt='%b %Y', length=250,
             format_args['series_index'] = mi.format_series_index()
     else:
         template = re.sub(r'\{series_index[^}]*?\}', '', template)
-    ## TODO: format custom values. Check all the datatypes.
+    ## TODO: NEWMETA: format custom values. Check all the datatypes.
 
     if mi.rating is not None:
         format_args['rating'] = mi.format_rating()