Adust the as_table tag to render a pick link if appropriate
The templates are adjusted to pass on a 'reference' value, which
is the url_name of the view from which the entity should be picked.
The as_table (and related) function(s) construct and then pass on
this argument and enable takes_contex so that we have access to the
context of the enclosing template.
We only extract ReferenceProperties that end with '_link_id' since
that is how all RP's are currently named. It is not possible to
create a field with the same name as the RP, as GAE will try to
interpret it's contents as the key of an entity before even calling
any function we can override.
Patch by: Sverre Rabbelier
#!/usr/bin/python2.5
#
# Copyright 2008 the Melange authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Module containing enhanced db.Model classes.
The classes in this module are intended to serve as base classes for all
Melange Datastore Models.
"""
__authors__ = [
'"Todd Larsen" <tlarsen@google.com>',
]
from google.appengine.ext import db
from soc.views.helper import forms as forms_helper
class ModelWithFieldAttributes(db.Model):
"""A db.Model extension that provides access to Model properties attributes.
Due to the way the Property class in Google App Engine implements __get__()
and __set__(), it is not possible to access attributes of Model properties,
such as verbose_name, from within a Django template. This class works
around that limitation by creating an inner Form class per Model class,
since an unbound Form object contains (most of?) the property attributes
attached to each corresponding Form field.
Some are attributes are renamed during the conversion from a Model Property
to a Form field; for example, verbose_name becomes label. This is tolerable
because any actual Form code refers to these new names, so they are should
be familiar to view creators.
"""
_fields_cache = None
@classmethod
def fields(cls):
"""Called by the Django template engine during template instantiation.
Since the attribute names use the Form fields naming instead of the
Property attribute naming, accessing, for example:
{{ entity.property.verbose_name }}
is accomplished using:
{{ entity.fields.property.label }}
Args:
cls: Model class, so that each Model class can create its own
unbound Form the first time fields() is called by the Django
template engine.
Returns:
A (created-on-first-use) unbound Form object that can be used to
access Property attributes that are not accessible from the
Property itself via the Model entity.
"""
if not cls._fields_cache or (cls != cls._fields_cache.__class__.Meta.model):
class FieldsProxy(forms_helper.BaseForm):
"""Form used as a proxy to access User model properties attributes.
"""
class Meta:
"""Inner Meta class that pairs the User Model with this "form".
"""
#: db.Model subclass for which to access model properties attributes
model = cls
cls._fields_cache = FieldsProxy()
return cls._fields_cache