Fix some circular imports, ready for py3.

ckan/model/__init__.py

@@ -27,9 +27,11 @@
     engine_is_pg,
 )
 from ckan.model.core import (
-    System,
     State,
 )
+from ckan.model.system import (
+    System,
+)
 from ckan.model.package import (
     Package,
     PACKAGE_NAME_MIN_LENGTH,

ckan/model/core.py

@@ -1,28 +1,8 @@
 # encoding: utf-8
 
-from ckan.model import domain_object
-
-
-__all__ = ['System', 'State', 'StatefulObjectMixin']
 log = __import__('logging').getLogger(__name__)
 
 
-class System(domain_object.DomainObject):
-
-    name = 'system'
-
-    def __unicode__(self):
-        return u'<%s>' % self.__class__.__name__
-
-    def purge(self):
-        pass
-
-    @classmethod
-    def by_name(cls, name):
-        return System()
-
-
-# VDM-specific domain objects
 class State(object):
     ACTIVE = u'active'
     DELETED = u'deleted'

ckan/model/package.py

@@ -553,3 +553,12 @@ class RatingValueException(Exception):
     order_by=package_table.c.name,
     extension=[extension.PluginMapperExtension()],
     )
+
+meta.mapper(tag.PackageTag, tag.package_tag_table, properties={
+    'pkg':orm.relation(Package, backref='package_tag_all',
+        cascade='none',
+        )
+    },
+    order_by=tag.package_tag_table.c.id,
+    extension=[extension.PluginMapperExtension()],
+    )

ckan/model/system.py

@@ -0,0 +1,18 @@
+# encoding: utf-8
+
+from ckan.model import domain_object
+
+
+class System(domain_object.DomainObject):
+
+    name = u'system'
+
+    def __unicode__(self):
+        return u'<%s>' % self.__class__.__name__
+
+    def purge(self):
+        pass
+
+    @classmethod
+    def by_name(cls, name):
+        return System()

ckan/model/tag.py

@@ -9,10 +9,10 @@
     types as _types,
     domain_object,
     vocabulary,
-    package as _package,
     extension as _extension,
 )
 import ckan  # this import is needed
+import ckan.model
 import ckan.lib.dictization
 import ckan.lib.maintain as maintain
 
@@ -207,11 +207,11 @@ def packages(self):
         :rtype: list of ckan.model.package.Package objects
 
         '''
-        q = meta.Session.query(_package.Package)
+        q = meta.Session.query(ckan.model.package.Package)
         q = q.join(PackageTag)
         q = q.filter_by(tag_id=self.id)
         q = q.filter_by(state='active')
-        q = q.order_by(_package.Package.name)
+        q = q.order_by(ckan.model.package.Package.name)
         packages = q.all()
         return packages
 
@@ -262,13 +262,13 @@ def by_name(self, package_name, tag_name, vocab_id_or_name=None,
             if vocab is None:
                 # The user specified an invalid vocab.
                 return None
-            query = (meta.Session.query(PackageTag, Tag, _package.Package)
+            query = (meta.Session.query(PackageTag, Tag, ckan.model.Package)
                     .filter(Tag.vocabulary_id == vocab.id)
-                    .filter(_package.Package.name==package_name)
+                    .filter(ckan.model.Package.name==package_name)
                     .filter(Tag.name==tag_name))
         else:
             query = (meta.Session.query(PackageTag)
-                    .filter(_package.Package.name==package_name)
+                    .filter(ckan.model.Package.name==package_name)
                     .filter(Tag.name==tag_name))
         query = query.autoflush(autoflush)
         return query.one()[0]
@@ -286,11 +286,5 @@ def related_packages(self):
     order_by=tag_table.c.name,
     )
 
-meta.mapper(PackageTag, package_tag_table, properties={
-    'pkg':relation(_package.Package, backref='package_tag_all',
-        cascade='none',
-        )
-    },
-    order_by=package_tag_table.c.id,
-    extension=[_extension.PluginMapperExtension()],
-    )
+# NB meta.mapper(tag.PackageTag... is found in package.py, because if it was
+# here it we'd get circular references

ckan/model/vocabulary.py

@@ -2,7 +2,7 @@
 
 from sqlalchemy import types, Column, Table
 
-from ckan.model import meta, types as _types, tag, domain_object
+from ckan.model import meta, types as _types, domain_object
 
 VOCABULARY_NAME_MIN_LENGTH = 2
 VOCABULARY_NAME_MAX_LENGTH = 100
@@ -35,6 +35,7 @@ def get(cls, id_or_name):
 
     @property
     def tags(self):
+        from ckan.model import tag
         query = meta.Session.query(tag.Tag)
         return query.filter(tag.Tag.vocabulary_id == self.id)
 

ckan/plugins/__init__.py

@@ -3,4 +3,4 @@
 from ckan.plugins.core import *
 from ckan.plugins.interfaces import *
 
-import toolkit
+from ckan.plugins import toolkit

ckan/plugins/core.py

@@ -14,7 +14,7 @@
 from ckan.common import asbool
 from six import string_types
 
-import interfaces
+from ckan.plugins import interfaces
 
 from ckan.common import config