author | Sverre Rabbelier <srabbelier@gmail.com> |
Fri, 10 Apr 2009 11:27:33 +0000 | |
changeset 2143 | 67c1cb524b78 |
parent 828 | f5fd65cc3bf3 |
child 2864 | 2e0b0af889be |
permissions | -rwxr-xr-x |
828
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
1 |
#!/usr/bin/env python |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
2 |
# |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
3 |
# Copyright 2007 Google Inc. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
4 |
# |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
5 |
# Licensed under the Apache License, Version 2.0 (the "License"); |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
6 |
# you may not use this file except in compliance with the License. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
7 |
# You may obtain a copy of the License at |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
8 |
# |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
9 |
# http://www.apache.org/licenses/LICENSE-2.0 |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
10 |
# |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
11 |
# Unless required by applicable law or agreed to in writing, software |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
12 |
# distributed under the License is distributed on an "AS IS" BASIS, |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
13 |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
14 |
# See the License for the specific language governing permissions and |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
15 |
# limitations under the License. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
16 |
# |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
17 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
18 |
"""Support for polymorphic models and queries. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
19 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
20 |
The Model class on its own is only able to support functional polymorphism. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
21 |
It is possible to create a subclass of Model and then subclass that one as |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
22 |
many generations as necessary and those classes will share all the same |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
23 |
properties and behaviors. The problem is that subclassing Model in this way |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
24 |
places each subclass in their own Kind. This means that it is not possible |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
25 |
to do polymorphic queries. Building a query on a base class will only return |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
26 |
instances of that class from the Datastore, while queries on a subclass will |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
27 |
only return those instances. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
28 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
29 |
This module allows applications to specify class hierarchies that support |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
30 |
polymorphic queries. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
31 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
32 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
33 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
34 |
from google.appengine.ext import db |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
35 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
36 |
_class_map = {} |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
37 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
38 |
_CLASS_KEY_PROPERTY = 'class' |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
39 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
40 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
41 |
class _ClassKeyProperty(db.ListProperty): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
42 |
"""Property representing class-key property of a polymorphic class. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
43 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
44 |
The class key is a list of strings describing an polymorphic instances |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
45 |
place within its class hierarchy. This property is automatically calculated. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
46 |
For example: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
47 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
48 |
class Foo(PolyModel): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
49 |
class Bar(Foo): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
50 |
class Baz(Bar): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
51 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
52 |
Foo.class_key() == ['Foo'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
53 |
Bar.class_key() == ['Foo', 'Bar'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
54 |
Baz.class_key() == ['Foo', 'Bar', 'Baz'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
55 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
56 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
57 |
def __init__(self, name): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
58 |
super(_ClassKeyProperty, self).__init__(name=name, |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
59 |
item_type=str, |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
60 |
default=None) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
61 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
62 |
def __set__(self, *args): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
63 |
raise db.DerivedPropertyError( |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
64 |
'Class-key is a derived property and cannot be set.') |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
65 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
66 |
def __get__(self, model_instance, model_class): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
67 |
if model_instance is None: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
68 |
return self |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
69 |
return [cls.__name__ for cls in model_class.__class_hierarchy__] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
70 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
71 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
72 |
class PolymorphicClass(db.PropertiedClass): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
73 |
"""Meta-class for initializing PolymorphicClasses. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
74 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
75 |
This class extends PropertiedClass to add a few static attributes to |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
76 |
new polymorphic classes necessary for their correct functioning. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
77 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
78 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
79 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
80 |
def __init__(cls, name, bases, dct): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
81 |
"""Initializes a class that belongs to a polymorphic hierarchy. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
82 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
83 |
This method configures a few built-in attributes of polymorphic |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
84 |
models: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
85 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
86 |
__root_class__: If the new class is a root class, __root_class__ is set to |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
87 |
itself so that it subclasses can quickly know what the root of |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
88 |
their hierarchy is and what kind they are stored in. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
89 |
__class_hierarchy__: List of classes describing the new model's place |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
90 |
in the class hierarchy. The first element is always the root |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
91 |
element while the last element is the new class itself. For example: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
92 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
93 |
class Foo(PolymorphicClass): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
94 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
95 |
class Bar(Foo): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
96 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
97 |
class Baz(Bar): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
98 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
99 |
Foo.__class_hierarchy__ == [Foo] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
100 |
Bar.__class_hierarchy__ == [Foo, Bar] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
101 |
Baz.__class_hierarchy__ == [Foo, Bar, Baz] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
102 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
103 |
Unless the class is a root class or PolyModel itself, it is not |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
104 |
inserted in to the kind-map like other models. However, all polymorphic |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
105 |
classes, are inserted in to the class-map which maps the class-key to |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
106 |
implementation. This class key is consulted using the polymorphic instances |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
107 |
discriminator (the 'class' property of the entity) when loading from the |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
108 |
datastore. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
109 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
110 |
if name == 'PolyModel' or PolyModel not in bases: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
111 |
db._initialize_properties(cls, name, bases, dct) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
112 |
super(db.PropertiedClass, cls).__init__(name, bases, dct) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
113 |
else: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
114 |
cls.__root_class__ = cls |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
115 |
super(PolymorphicClass, cls).__init__(name, bases, dct) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
116 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
117 |
if name == 'PolyModel': |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
118 |
return |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
119 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
120 |
if cls is not cls.__root_class__: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
121 |
poly_class = None |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
122 |
for base in cls.__bases__: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
123 |
if issubclass(base, PolyModel): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
124 |
poly_class = base |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
125 |
break |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
126 |
else: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
127 |
raise db.ConfigurationError( |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
128 |
"Polymorphic class '%s' does not inherit from PolyModel." |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
129 |
% cls.__name__) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
130 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
131 |
cls.__class_hierarchy__ = poly_class.__class_hierarchy__ + [cls] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
132 |
else: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
133 |
cls.__class_hierarchy__ = [cls] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
134 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
135 |
_class_map[cls.class_key()] = cls |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
136 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
137 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
138 |
class PolyModel(db.Model): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
139 |
"""Base-class for models that supports polymorphic queries. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
140 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
141 |
Use this class to build hierarchies that can be queried based |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
142 |
on their types. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
143 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
144 |
Example: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
145 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
146 |
consider the following model hierarchy: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
147 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
148 |
+------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
149 |
|Animal| |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
150 |
+------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
151 |
| |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
152 |
+-----------------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
153 |
| | |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
154 |
+------+ +------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
155 |
|Canine| |Feline| |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
156 |
+------+ +------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
157 |
| | |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
158 |
+-------+ +-------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
159 |
| | | | |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
160 |
+---+ +----+ +---+ +-------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
161 |
|Dog| |Wolf| |Cat| |Panther| |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
162 |
+---+ +----+ +---+ +-------+ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
163 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
164 |
This class hierarchy has three levels. The first is the "root class". |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
165 |
All models in a single class hierarchy must inherit from this root. All |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
166 |
models in the hierarchy are stored as the same kind as the root class. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
167 |
For example, Panther entities when stored to the datastore are of the kind |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
168 |
'Animal'. Querying against the Animal kind will retrieve Cats, Dogs and |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
169 |
Canines, for example, that match your query. Different classes stored |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
170 |
in the root class' kind are identified by their class-key. When loaded |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
171 |
from the datastore, it is mapped to the appropriate implementation class. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
172 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
173 |
Polymorphic properties: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
174 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
175 |
Properties that are defined in a given base-class within a hierarchy are |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
176 |
stored in the datastore for all sub-casses only. So, if the Feline class |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
177 |
had a property called 'whiskers', the Cat and Panther enties would also |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
178 |
have whiskers, but not Animal, Canine, Dog or Wolf. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
179 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
180 |
Polymorphic queries: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
181 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
182 |
When written to the datastore, all polymorphic objects automatically have |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
183 |
a property called 'class' that you can query against. Using this property |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
184 |
it is possible to easily write a GQL query against any sub-hierarchy. For |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
185 |
example, to fetch only Canine objects, including all Dogs and Wolves: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
186 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
187 |
db.GqlQuery("SELECT * FROM Animal WHERE class='Canine'") |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
188 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
189 |
And alternate method is to use the 'all' or 'gql' methods of the Canine |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
190 |
class: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
191 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
192 |
Canine.all() |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
193 |
Canine.gql('') |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
194 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
195 |
The 'class' property is not meant to be used by your code other than |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
196 |
for queries. Since it is supposed to represents the real Python class |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
197 |
it is intended to be hidden from view. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
198 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
199 |
Root class: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
200 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
201 |
The root class is the class from which all other classes of the hierarchy |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
202 |
inherits from. Each hierarchy has a single root class. A class is a |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
203 |
root class if it is an immediate child of PolyModel. The subclasses of |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
204 |
the root class are all the same kind as the root class. In other words: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
205 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
206 |
Animal.kind() == Feline.kind() == Panther.kind() == 'Animal' |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
207 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
208 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
209 |
__metaclass__ = PolymorphicClass |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
210 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
211 |
_class = _ClassKeyProperty(name=_CLASS_KEY_PROPERTY) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
212 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
213 |
def __new__(cls, *args, **kwds): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
214 |
"""Prevents direct instantiation of PolyModel.""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
215 |
if cls is PolyModel: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
216 |
raise NotImplementedError() |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
217 |
return super(PolyModel, cls).__new__(cls, *args, **kwds) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
218 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
219 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
220 |
def kind(cls): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
221 |
"""Get kind of polymorphic model. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
222 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
223 |
Overridden so that all subclasses of root classes are the same kind |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
224 |
as the root. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
225 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
226 |
Returns: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
227 |
Kind of entity to write to datastore. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
228 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
229 |
if cls is cls.__root_class__: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
230 |
return super(PolyModel, cls).kind() |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
231 |
else: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
232 |
return cls.__root_class__.kind() |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
233 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
234 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
235 |
def class_key(cls): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
236 |
"""Caclulate the class-key for this class. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
237 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
238 |
Returns: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
239 |
Class key for class. By default this is a the list of classes |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
240 |
of the hierarchy, starting with the root class and walking its way |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
241 |
down to cls. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
242 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
243 |
if not hasattr(cls, '__class_hierarchy__'): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
244 |
raise NotImplementedError( |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
245 |
'Cannot determine class key without class hierarchy') |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
246 |
return tuple(cls.class_name() for cls in cls.__class_hierarchy__) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
247 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
248 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
249 |
def class_name(cls): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
250 |
"""Calculate class name for this class. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
251 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
252 |
Returns name to use for each classes element within its class-key. Used |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
253 |
to discriminate between different classes within a class hierarchy's |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
254 |
Datastore kind. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
255 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
256 |
The presence of this method allows developers to use a different class |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
257 |
name in the datastore from what is used in Python code. This is useful, |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
258 |
for example, for renaming classes without having to migrate instances |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
259 |
already written to the datastore. For example, to rename a polymorphic |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
260 |
class Contact to SimpleContact, you could convert: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
261 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
262 |
# Class key is ['Information'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
263 |
class Information(PolyModel): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
264 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
265 |
# Class key is ['Information', 'Contact'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
266 |
class Contact(Information): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
267 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
268 |
to: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
269 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
270 |
# Class key is still ['Information', 'Contact'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
271 |
class SimpleContact(Information): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
272 |
... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
273 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
274 |
def class_name(cls): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
275 |
return 'Contact' |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
276 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
277 |
# Class key is ['Information', 'Contact', 'ExtendedContact'] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
278 |
class ExtendedContact(SimpleContact): ... |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
279 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
280 |
This would ensure that all objects written previously using the old class |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
281 |
name would still be loaded. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
282 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
283 |
Returns: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
284 |
Name of this class. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
285 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
286 |
return cls.__name__ |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
287 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
288 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
289 |
def from_entity(cls, entity): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
290 |
"""Load from entity to class based on discriminator. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
291 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
292 |
Rather than instantiating a new Model instance based on the kind |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
293 |
mapping, this creates an instance of the correct model class based |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
294 |
on the entities class-key. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
295 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
296 |
Args: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
297 |
entity: Entity loaded directly from datastore. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
298 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
299 |
Raises: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
300 |
KindError when there is no class mapping based on discriminator. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
301 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
302 |
if (_CLASS_KEY_PROPERTY in entity and |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
303 |
tuple(entity[_CLASS_KEY_PROPERTY]) != cls.class_key()): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
304 |
key = tuple(entity[_CLASS_KEY_PROPERTY]) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
305 |
try: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
306 |
poly_class = _class_map[key] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
307 |
except KeyError: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
308 |
raise db.KindError('No implementation for class \'%s\'' % key) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
309 |
return poly_class.from_entity(entity) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
310 |
return super(PolyModel, cls).from_entity(entity) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
311 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
312 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
313 |
def all(cls): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
314 |
"""Get all instance of a class hierarchy. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
315 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
316 |
Returns: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
317 |
Query with filter set to match this class' discriminator. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
318 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
319 |
query = super(PolyModel, cls).all() |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
320 |
if cls != cls.__root_class__: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
321 |
query.filter(_CLASS_KEY_PROPERTY + ' =', cls.class_name()) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
322 |
return query |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
323 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
324 |
@classmethod |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
325 |
def gql(cls, query_string, *args, **kwds): |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
326 |
"""Returns a polymorphic query using GQL query string. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
327 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
328 |
This query is polymorphic in that it has its filters configured in a way |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
329 |
to retrieve instances of the model or an instance of a subclass of the |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
330 |
model. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
331 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
332 |
Args: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
333 |
query_string: properly formatted GQL query string with the |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
334 |
'SELECT * FROM <entity>' part omitted |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
335 |
*args: rest of the positional arguments used to bind numeric references |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
336 |
in the query. |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
337 |
**kwds: dictionary-based arguments (for named parameters). |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
338 |
""" |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
339 |
if cls == cls.__root_class__: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
340 |
return super(PolyModel, cls).gql(query_string, *args, **kwds) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
341 |
else: |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
342 |
from google.appengine.ext import gql |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
343 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
344 |
query = db.GqlQuery('SELECT * FROM %s %s' % (cls.kind(), query_string)) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
345 |
|
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
346 |
query_filter = [('nop', |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
347 |
[gql.Literal(cls.class_name())])] |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
348 |
query._proto_query.filters()[('class', '=')] = query_filter |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
349 |
query.bind(*args, **kwds) |
f5fd65cc3bf3
Load /Users/solydzajs/Downloads/google_appengine into
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
350 |
return query |