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Project/ModelState now correctly serialize multi-model inheritance

This commit is contained in:
Andrew Godwin 2013-09-06 12:14:09 -05:00
parent 6f7977bb63
commit cdeff3acc2
2 changed files with 104 additions and 5 deletions
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37
django/db/migrations/state.py
View File

@ -1,9 +1,14 @@
from django.db import models
from django.db.models.loading import BaseAppCache
from django.db.models.options import DEFAULT_NAMES
from django.utils import six
from django.utils.module_loading import import_by_path
class InvalidBasesError(ValueError):
pass
class ProjectState(object):
"""
Represents the entire project's overall state.
@ -28,8 +33,21 @@ class ProjectState(object):
"Turns the project state into actual models in a new AppCache"
if self.app_cache is None:
self.app_cache = BaseAppCache()
for model in self.models.values():
model.render(self.app_cache)
# We keep trying to render the models in a loop, ignoring invalid
# base errors, until the size of the unrendered models doesn't
# decrease by at least one, meaning there's a base dependency loop/
# missing base.
unrendered_models = list(self.models.values())
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.app_cache)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError("Cannot resolve bases for %r" % new_unrendered_models)
unrendered_models = new_unrendered_models
return self.app_cache
@classmethod
@ -86,7 +104,11 @@ class ModelState(object):
else:
options[name] = model._meta.original_attrs[name]
# Make our record
bases = tuple(model for model in model.__bases__ if (not hasattr(model, "_meta") or not model._meta.abstract))
bases = tuple(
("%s.%s" % (base._meta.app_label, base._meta.object_name.lower()) if hasattr(base, "_meta") else base)
for base in model.__bases__
if (not hasattr(base, "_meta") or not base._meta.abstract)
)
if not bases:
bases = (models.Model, )
return cls(
@ -123,7 +145,12 @@ class ModelState(object):
meta_contents["unique_together"] = list(meta_contents["unique_together"])
meta = type("Meta", tuple(), meta_contents)
# Then, work out our bases
# TODO: Use the actual bases
bases = tuple(
(app_cache.get_model(*base.split(".", 1)) if isinstance(base, six.string_types) else base)
for base in self.bases
)
if None in bases:
raise InvalidBasesError("Cannot resolve one or more bases from %r" % self.bases)
# Turn fields into a dict for the body, add other bits
body = dict(self.fields)
body['Meta'] = meta
@ -131,7 +158,7 @@ class ModelState(object):
# Then, make a Model object
return type(
self.name,
tuple(self.bases),
bases,
body,
)

72
tests/migrations/test_state.py
View File

@ -25,6 +25,13 @@ class StateTests(TestCase):
app_cache = new_app_cache
unique_together = ["name", "bio"]
class AuthorProxy(Author):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
proxy = True
ordering = ["name"]
class Book(models.Model):
title = models.CharField(max_length=1000)
author = models.ForeignKey(Author)
@ -36,6 +43,7 @@ class StateTests(TestCase):
project_state = ProjectState.from_app_cache(new_app_cache)
author_state = project_state.models['migrations', 'author']
author_proxy_state = project_state.models['migrations', 'authorproxy']
book_state = project_state.models['migrations', 'book']
self.assertEqual(author_state.app_label, "migrations")
@ -55,6 +63,12 @@ class StateTests(TestCase):
self.assertEqual(book_state.options, {"verbose_name": "tome", "db_table": "test_tome"})
self.assertEqual(book_state.bases, (models.Model, ))
self.assertEqual(author_proxy_state.app_label, "migrations")
self.assertEqual(author_proxy_state.name, "AuthorProxy")
self.assertEqual(author_proxy_state.fields, [])
self.assertEqual(author_proxy_state.options, {"proxy": True, "ordering": ["name"]})
self.assertEqual(author_proxy_state.bases, ("migrations.author", ))
def test_render(self):
"""
Tests rendering a ProjectState into an AppCache.
@ -92,5 +106,63 @@ class StateTests(TestCase):
app_label = "migrations"
app_cache = new_app_cache
# First, test rendering individually
yet_another_app_cache = BaseAppCache()
# We shouldn't be able to render yet
with self.assertRaises(ValueError):
ModelState.from_model(Novel).render(yet_another_app_cache)
# Once the parent model is in the app cache, it should be fine
ModelState.from_model(Book).render(yet_another_app_cache)
ModelState.from_model(Novel).render(yet_another_app_cache)
def test_render_project_dependencies(self):
"""
Tests that the ProjectState render method correctly renders models
to account for inter-model base dependencies.
"""
new_app_cache = BaseAppCache()
class A(models.Model):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
class B(A):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
class C(B):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
class D(A):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
class E(B):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
proxy = True
class F(D):
class Meta:
app_label = "migrations"
app_cache = new_app_cache
proxy = True
# Make a ProjectState and render it
project_state = ProjectState()
project_state.add_model_state(ModelState.from_model(A))
project_state.add_model_state(ModelState.from_model(B))
project_state.add_model_state(ModelState.from_model(C))
project_state.add_model_state(ModelState.from_model(D))
project_state.add_model_state(ModelState.from_model(E))
project_state.add_model_state(ModelState.from_model(F))
final_app_cache = project_state.render()
self.assertEqual(len(final_app_cache.get_models()), 6)