def render(self, include_real=None, ignore_swappable=False, skip_cache=False):
"Turns the project state into actual models in a new Apps"
if self.apps is None or skip_cache:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
# FKs/M2Ms from real apps are also not included as they just
# mess things up with partial states (due to lack of dependencies)
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(ModelState.from_model(model, exclude_rels=True))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label for model_state in self.models.values())
self.apps = Apps([AppConfigStub(label) for label in sorted(self.real_apps + list(app_labels))])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError(
"Cannot resolve bases for %r\nThis can happen if you are inheriting models from an "
"app with migrations (e.g. contrib.auth)\n in an app with no migrations; see "
"https://docs.djangoproject.com/en/1.7/topics/migrations/#dependencies "
"for more" % new_unrendered_models
)
unrendered_models = new_unrendered_models
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items():
try:
model = self.apps.get_model(lookup_model[0], lookup_model[1])
except LookupError:
app_label = "%s.%s" % (lookup_model[0], lookup_model[1])
if app_label == settings.AUTH_USER_MODEL and ignore_swappable:
continue
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
msg = "Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}"
raise ValueError(msg.format(field=operations[0][1], model=lookup_model))
else:
do_pending_lookups(model)
try:
return self.apps
finally:
if skip_cache:
self.apps = None
def render(self):
"Turns the project state into actual models in a new Apps"
if self.apps is None:
self.apps = Apps()
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label for model_state in self.models.values())
app_configs = [AppConfigStub(label) for label in sorted(app_labels)]
self.apps.populate_apps(app_configs)
self.apps.populate_models()
# 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.apps)
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.apps
def get_models():
result = []
apps = Apps(settings.INSTALLED_APPS)
for app_config in apps.get_app_configs():
try:
import_module('%s.comments' % app_config.module.__name__)
except ImportError:
pass
except Exception as e:
raise e
for attr_name in dir(app_config.models_module):
attr = getattr(app_config.models_module, attr_name)
if isinstance(attr, ModelBase) and attr.__module__ == '%s.models' % app_config.module.__name__:
result.append(attr)
return result
def render(self, include_real=None):
"Turns the project state into actual models in a new Apps"
if self.apps is None:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(ModelState.from_model(model))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label for model_state in self.models.values())
self.apps = Apps([AppConfigStub(label) for label in sorted(self.real_apps + list(app_labels))])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
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
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items():
try:
model = self.apps.get_model(lookup_model[0], lookup_model[1])
except LookupError:
# If the lookup failed to something that looks like AUTH_USER_MODEL,
# give a better error message about how you can't change it (#22563)
extra_message = ""
if "%s.%s" % (lookup_model[0], lookup_model[1]) == settings.AUTH_USER_MODEL:
extra_message = (
"\nThe missing model matches AUTH_USER_MODEL; if you've changed the value of this" +
"\nsetting after making a migration, be aware that this is not supported. If you" +
"\nchange AUTH_USER_MODEL you must delete and recreate migrations for its app."
)
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
raise ValueError("Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}{extra_message}".format(
field = operations[0][1],
model = lookup_model,
extra_message = extra_message,
))
else:
do_pending_lookups(model)
return self.apps
def test_dynamic_load(self):
"""
Makes a new model at runtime and ensures it goes into the right place.
"""
old_models = apps.get_models(apps.get_app_config("apps").models_module)
# Construct a new model in a new app registry
body = {}
new_apps = Apps()
meta_contents = {"app_label": "apps", "apps": new_apps}
meta = type(str("Meta"), tuple(), meta_contents)
body["Meta"] = meta
body["__module__"] = TotallyNormal.__module__
temp_model = type(str("SouthPonies"), (models.Model,), body)
# Make sure it appeared in the right place!
self.assertEqual(old_models, apps.get_models(apps.get_app_config("apps").models_module))
with self.assertRaises(LookupError):
apps.get_model("apps", "SouthPonies")
self.assertEqual(new_apps.get_model("apps", "SouthPonies"), temp_model)
def test_dynamic_load(self):
"""
Makes a new model at runtime and ensures it goes into the right place.
"""
old_models = list(apps.get_app_config("apps").get_models())
# Construct a new model in a new app registry
body = {}
new_apps = Apps(["apps"])
meta_contents = {
'app_label': "apps",
'apps': new_apps,
}
meta = type("Meta", tuple(), meta_contents)
body['Meta'] = meta
body['__module__'] = TotallyNormal.__module__
temp_model = type("SouthPonies", (models.Model,), body)
# Make sure it appeared in the right place!
self.assertEqual(list(apps.get_app_config("apps").get_models()), old_models)
with self.assertRaises(LookupError):
apps.get_model("apps", "SouthPonies")
self.assertEqual(new_apps.get_model("apps", "SouthPonies"), temp_model)
def test_create(self):
"""
Tests making a ProjectState from an Apps
"""
new_apps = Apps(["migrations"])
class Author(models.Model):
name = models.CharField(max_length=255)
bio = models.TextField()
age = models.IntegerField(blank=True, null=True)
class Meta:
app_label = "migrations"
apps = new_apps
unique_together = ["name", "bio"]
index_together = ["bio", "age"]
class AuthorProxy(Author):
class Meta:
app_label = "migrations"
apps = new_apps
proxy = True
ordering = ["name"]
class SubAuthor(Author):
width = models.FloatField(null=True)
class Meta:
app_label = "migrations"
apps = new_apps
class Book(models.Model):
title = models.CharField(max_length=1000)
author = models.ForeignKey(Author)
contributors = models.ManyToManyField(Author)
class Meta:
app_label = "migrations"
apps = new_apps
verbose_name = "tome"
db_table = "test_tome"
class Food(models.Model):
food_mgr = FoodManager('a', 'b')
food_qs = FoodQuerySet.as_manager()
food_no_mgr = NoMigrationFoodManager('x', 'y')
class Meta:
app_label = "migrations"
apps = new_apps
class FoodNoManagers(models.Model):
class Meta:
app_label = "migrations"
apps = new_apps
class FoodNoDefaultManager(models.Model):
food_no_mgr = NoMigrationFoodManager('x', 'y')
food_mgr = FoodManager('a', 'b')
food_qs = FoodQuerySet.as_manager()
class Meta:
app_label = "migrations"
apps = new_apps
mgr1 = FoodManager('a', 'b')
mgr2 = FoodManager('x', 'y', c=3, d=4)
class FoodOrderedManagers(models.Model):
# The managers on this model should be ordered by their creation
# counter and not by the order in model body
food_no_mgr = NoMigrationFoodManager('x', 'y')
food_mgr2 = mgr2
food_mgr1 = mgr1
class Meta:
app_label = "migrations"
apps = new_apps
project_state = ProjectState.from_apps(new_apps)
author_state = project_state.models['migrations', 'author']
author_proxy_state = project_state.models['migrations', 'authorproxy']
sub_author_state = project_state.models['migrations', 'subauthor']
book_state = project_state.models['migrations', 'book']
food_state = project_state.models['migrations', 'food']
food_no_managers_state = project_state.models['migrations',
'foodnomanagers']
food_no_default_manager_state = project_state.models[
'migrations', 'foodnodefaultmanager']
food_order_manager_state = project_state.models['migrations',
'foodorderedmanagers']
self.assertEqual(author_state.app_label, "migrations")
self.assertEqual(author_state.name, "Author")
self.assertEqual([x for x, y in author_state.fields],
["id", "name", "bio", "age"])
self.assertEqual(author_state.fields[1][1].max_length, 255)
self.assertEqual(author_state.fields[2][1].null, False)
self.assertEqual(author_state.fields[3][1].null, True)
self.assertEqual(
author_state.options, {
"unique_together": {("name", "bio")},
"index_together": {("bio", "age")}
})
self.assertEqual(author_state.bases, (models.Model, ))
self.assertEqual(book_state.app_label, "migrations")
self.assertEqual(book_state.name, "Book")
self.assertEqual([x for x, y in book_state.fields],
["id", "title", "author", "contributors"])
self.assertEqual(book_state.fields[1][1].max_length, 1000)
self.assertEqual(book_state.fields[2][1].null, False)
self.assertEqual(book_state.fields[3][1].__class__.__name__,
"ManyToManyField")
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", ))
self.assertEqual(sub_author_state.app_label, "migrations")
self.assertEqual(sub_author_state.name, "SubAuthor")
self.assertEqual(len(sub_author_state.fields), 2)
self.assertEqual(sub_author_state.bases, ("migrations.author", ))
# The default manager is used in migrations
self.assertEqual([name for name, mgr in food_state.managers],
['food_mgr'])
self.assertTrue(
all(
isinstance(name, six.text_type)
for name, mgr in food_state.managers))
self.assertEqual(food_state.managers[0][1].args, ('a', 'b', 1, 2))
# No explicit managers defined. Migrations will fall back to the default
self.assertEqual(food_no_managers_state.managers, [])
# food_mgr is used in migration but isn't the default mgr, hence add the
# default
self.assertEqual(
[name for name, mgr in food_no_default_manager_state.managers],
['food_no_mgr', 'food_mgr'])
self.assertTrue(
all(
isinstance(name, six.text_type)
for name, mgr in food_no_default_manager_state.managers))
self.assertEqual(
food_no_default_manager_state.managers[0][1].__class__,
models.Manager)
self.assertIsInstance(food_no_default_manager_state.managers[1][1],
FoodManager)
self.assertEqual(
[name for name, mgr in food_order_manager_state.managers],
['food_mgr1', 'food_mgr2'])
self.assertTrue(
all(
isinstance(name, six.text_type)
for name, mgr in food_order_manager_state.managers))
self.assertEqual(
[mgr.args for name, mgr in food_order_manager_state.managers],
[('a', 'b', 1, 2), ('x', 'y', 3, 4)])
def setUp(self):
self.apps = Apps(['migrations.related_models_app'])
class Meta:
abstract = True
apps = Apps()
def test_wait_for_apps_ready_checks_for_exception(self):
app_reg = Apps()
app_reg.ready_event.set()
# thread.is_alive() is False if it's not started.
dead_thread = threading.Thread()
self.assertFalse(self.reloader.wait_for_apps_ready(app_reg, dead_thread))
class Meta:
apps = Apps()
app_label = "channels"
db_table = "django_channels"
class Meta:
verbose_name = 'a model created on the fly'
app_label = 'my_great_app'
apps = Apps()
def handle_django_settings(filename):
'''Attempts to load a Django project and get package dependencies from
settings.
Tested using Django 1.4 and 1.8. Not sure if some nuances are missed in
the other versions.
'''
old_sys_path = sys.path[:]
dirpath = os.path.dirname(filename)
project = os.path.basename(dirpath)
cwd = os.getcwd()
project_path = os.path.normpath(os.path.join(dirpath, '..'))
if project_path not in sys.path:
sys.path.insert(0, project_path)
os.chdir(project_path)
project_settings = '{}.settings'.format(project)
os.environ['DJANGO_SETTINGS_MODULE'] = project_settings
try:
import django
# Sanity
django.setup = lambda: False
except ImportError:
log.error('Found Django settings, but Django is not installed.')
return
log.warn('Loading Django Settings (Using {}): {}'.format(
django.get_version(), filename))
from django.conf import LazySettings
installed_apps = set()
settings_imports = set()
try:
settings = LazySettings()
settings._setup()
for k, v in vars(settings._wrapped).items():
if k not in _excluded_settings and re.match(r'^[A-Z_]+$', k):
# log.debug('Scanning Django setting: %s', k)
scan_django_settings(v, settings_imports)
# Manually scan INSTALLED_APPS since the broad scan won't include
# strings without a period in it .
for app in getattr(settings, 'INSTALLED_APPS', []):
if hasattr(app, '__file__') and getattr(app, '__file__'):
imp, _ = utils.import_path_from_file(getattr(app, '__file__'))
installed_apps.add(imp)
else:
installed_apps.add(app)
except Exception as e:
log.error('Could not load Django settings: %s', e)
log.debug('', exc_info=True)
return
if not installed_apps or not settings_imports:
log.error('Got empty settings values from Django settings.')
try:
from django.apps.registry import apps, Apps, AppRegistryNotReady
# Django doesn't like it when the initial instance of `apps` is reused,
# but it has to be populated before other instances can be created.
if not apps.apps_ready:
apps.populate(installed_apps)
else:
apps = Apps(installed_apps)
start = time.time()
while True:
try:
for app in apps.get_app_configs():
installed_apps.add(app.name)
except AppRegistryNotReady:
if time.time() - start > 10:
raise Exception('Bail out of waiting for Django')
log.debug('Waiting for apps to load...')
continue
break
except Exception as e:
log.debug('Could not use AppConfig: {}'.format(e))
# Restore before sub scans can occur
sys.path[:] = old_sys_path
os.chdir(cwd)
for item in settings_imports:
need_scan = item.startswith(_filescan_modules)
yield ('django', item, project_path if need_scan else None)
for app in installed_apps:
need_scan = app.startswith(project)
yield ('django', app, project_path if need_scan else None)
class Meta:
apps = Apps()
app_label = 'migrations'
db_table = 'django_migrations'
def test_dangling_references_throw_error(self):
new_apps = Apps()
class Author(models.Model):
name = models.TextField()
class Meta:
app_label = "migrations"
apps = new_apps
class Publisher(models.Model):
name = models.TextField()
class Meta:
app_label = "migrations"
apps = new_apps
class Book(models.Model):
author = models.ForeignKey(Author, models.CASCADE)
publisher = models.ForeignKey(Publisher, models.CASCADE)
class Meta:
app_label = "migrations"
apps = new_apps
class Magazine(models.Model):
authors = models.ManyToManyField(Author)
class Meta:
app_label = "migrations"
apps = new_apps
# Make a valid ProjectState and render it
project_state = ProjectState()
project_state.add_model(ModelState.from_model(Author))
project_state.add_model(ModelState.from_model(Publisher))
project_state.add_model(ModelState.from_model(Book))
project_state.add_model(ModelState.from_model(Magazine))
self.assertEqual(len(project_state.apps.get_models()), 4)
# now make an invalid one with a ForeignKey
project_state = ProjectState()
project_state.add_model(ModelState.from_model(Book))
msg = (
"The field migrations.Book.author was declared with a lazy reference "
"to 'migrations.author', but app 'migrations' doesn't provide model 'author'.\n"
"The field migrations.Book.publisher was declared with a lazy reference "
"to 'migrations.publisher', but app 'migrations' doesn't provide model 'publisher'."
)
with self.assertRaisesMessage(ValueError, msg):
project_state.apps
# And another with ManyToManyField.
project_state = ProjectState()
project_state.add_model(ModelState.from_model(Magazine))
msg = (
"The field migrations.Magazine.authors was declared with a lazy reference "
"to 'migrations.author\', but app 'migrations' doesn't provide model 'author'.\n"
"The field migrations.Magazine_authors.author was declared with a lazy reference "
"to \'migrations.author\', but app 'migrations' doesn't provide model 'author'."
)
with self.assertRaisesMessage(ValueError, msg):
project_state.apps
# And now with multiple models and multiple fields.
project_state.add_model(ModelState.from_model(Book))
msg = (
"The field migrations.Book.author was declared with a lazy reference "
"to 'migrations.author', but app 'migrations' doesn't provide model 'author'.\n"
"The field migrations.Book.publisher was declared with a lazy reference "
"to 'migrations.publisher', but app 'migrations' doesn't provide model 'publisher'.\n"
"The field migrations.Magazine.authors was declared with a lazy reference "
"to 'migrations.author', but app 'migrations' doesn't provide model 'author'.\n"
"The field migrations.Magazine_authors.author was declared with a lazy reference "
"to 'migrations.author', but app 'migrations' doesn't provide model 'author'."
)
with self.assertRaisesMessage(ValueError, msg):
project_state.apps
def test_field_deconstruction(self):
test_apps = Apps()
class Foo(PolymorphicModel):
foo = PolymorphicTypeField('self', on_delete=models.CASCADE)
class Meta:
apps = test_apps
app_label = 'polymodels'
class Bar(models.Model):
foo = PolymorphicTypeField('Foo', on_delete=models.CASCADE)
foo_null = PolymorphicTypeField(Foo,
on_delete=models.CASCADE,
null=True)
foo_default = PolymorphicTypeField(
Foo,
on_delete=models.CASCADE,
default=get_content_type(Foo).pk)
class Meta:
apps = test_apps
app_label = 'polymodels'
def django_version_agnostic(deconstruction):
# As of Django 1.9+ on_delete is a required parameter and
# doesn't default to models.CASCADE anymore.
if django.VERSION >= (1, 9):
deconstruction['on_delete'] = models.CASCADE
return deconstruction
self.assertDeconstructionEqual(
Foo._meta.get_field('foo'),
('foo', 'django.db.models.fields.related.ForeignKey', [],
django_version_agnostic(
{
'to': 'contenttypes.ContentType',
'related_name': '+',
'default': ContentTypeReference('polymodels', 'foo'),
})))
self.assertDeconstructionEqual(
Bar._meta.get_field('foo'),
('foo', 'django.db.models.fields.related.ForeignKey', [],
django_version_agnostic(
{
'to': 'contenttypes.ContentType',
'related_name': '+',
'default': ContentTypeReference('polymodels', 'foo'),
})))
self.assertDeconstructionEqual(
Bar._meta.get_field('foo_null'),
('foo_null', 'django.db.models.fields.related.ForeignKey', [],
django_version_agnostic({
'to': 'contenttypes.ContentType',
'related_name': '+',
'null': True,
})))
self.assertDeconstructionEqual(
Bar._meta.get_field('foo_default'),
('foo_default', 'django.db.models.fields.related.ForeignKey', [],
django_version_agnostic({
'to': 'contenttypes.ContentType',
'related_name': '+',
'default': get_content_type(Foo).pk,
})))
def _remake_table(self, model, create_fields=[], delete_fields=[], alter_fields=[], rename_fields=[], override_uniques=None):
"""
Shortcut to transform a model from old_model into new_model
"""
# Work out the new fields dict / mapping
body = dict((f.name, f) for f in model._meta.local_fields)
mapping = dict((f.column, f.column) for f in model._meta.local_fields)
# If any of the new or altered fields is introducing a new PK,
# remove the old one
restore_pk_field = None
if any(f.primary_key for f in create_fields) or any(n.primary_key for o, n in alter_fields):
for name, field in list(body.items()):
if field.primary_key:
field.primary_key = False
restore_pk_field = field
if field.auto_created:
del body[name]
del mapping[field.column]
# Add in any created fields
for field in create_fields:
body[field.name] = field
# If there's a default, insert it into the copy map
if field.has_default():
mapping[field.column] = self.connection.ops.quote_parameter(
field.get_default()
)
# Add in any altered fields
for (old_field, new_field) in alter_fields:
del body[old_field.name]
del mapping[old_field.column]
body[new_field.name] = new_field
mapping[new_field.column] = old_field.column
# Remove any deleted fields
for field in delete_fields:
del body[field.name]
del mapping[field.column]
# Work inside a new app registry
apps = Apps()
# Construct a new model for the new state
meta_contents = {
'app_label': model._meta.app_label,
'db_table': model._meta.db_table + "__new",
'unique_together': model._meta.unique_together if override_uniques is None else override_uniques,
'apps': apps,
}
meta = type("Meta", tuple(), meta_contents)
body['Meta'] = meta
body['__module__'] = model.__module__
temp_model = type(model._meta.object_name, model.__bases__, body)
# Create a new table with that format
self.create_model(temp_model)
# Copy data from the old table
field_maps = list(mapping.items())
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
self.quote_name(temp_model._meta.db_table),
', '.join(x for x, y in field_maps),
', '.join(y for x, y in field_maps),
self.quote_name(model._meta.db_table),
))
# Delete the old table
self.delete_model(model)
# Rename the new to the old
self.alter_db_table(model, temp_model._meta.db_table, model._meta.db_table)
# Run deferred SQL on correct table
for sql in self.deferred_sql:
self.execute(sql.replace(temp_model._meta.db_table, model._meta.db_table))
self.deferred_sql = []
# Fix any PK-removed field
if restore_pk_field:
restore_pk_field.primary_key = True
from __future__ import unicode_literals
from django.apps.registry import Apps
from django.db import models
# We're testing app registry presence on load, so this is handy.
new_apps = Apps(['apps'])
class TotallyNormal(models.Model):
name = models.CharField(max_length=255)
class SoAlternative(models.Model):
name = models.CharField(max_length=255)
class Meta:
apps = new_apps
class ProjectState(object):
"""
Represents the entire project's overall state.
This is the item that is passed around - we do it here rather than at the
app level so that cross-app FKs/etc. resolve properly.
"""
def __init__(self, models=None, real_apps=None):
self.models = models or {}
self.apps = None
# Apps to include from main registry, usually unmigrated ones
self.real_apps = real_apps or []
def add_model_state(self, model_state):
self.models[(model_state.app_label, model_state.name.lower())] = model_state
def clone(self):
"Returns an exact copy of this ProjectState"
return ProjectState(
models=dict((k, v.clone()) for k, v in self.models.items()),
real_apps=self.real_apps,
)
def render(self, include_real=None):
"Turns the project state into actual models in a new Apps"
if self.apps is None:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(ModelState.from_model(model))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label for model_state in self.models.values())
self.apps = Apps([AppConfigStub(label) for label in sorted(self.real_apps + list(app_labels))])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
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
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items():
try:
model = self.apps.get_model(lookup_model[0], lookup_model[1])
except LookupError:
# If the lookup failed to something that looks like AUTH_USER_MODEL,
# give a better error message about how you can't change it (#22563)
extra_message = ""
if "%s.%s" % (lookup_model[0], lookup_model[1]) == settings.AUTH_USER_MODEL:
extra_message = (
"\nThe missing model matches AUTH_USER_MODEL; if you've changed the value of this" +
"\nsetting after making a migration, be aware that this is not supported. If you" +
"\nchange AUTH_USER_MODEL you must delete and recreate migrations for its app."
)
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
raise ValueError("Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}{extra_message}".format(
field = operations[0][1],
model = lookup_model,
extra_message = extra_message,
))
else:
do_pending_lookups(model)
return self.apps
@classmethod
def from_apps(cls, apps):
"Takes in an Apps and returns a ProjectState matching it"
app_models = {}
for model in apps.get_models():
model_state = ModelState.from_model(model)
app_models[(model_state.app_label, model_state.name.lower())] = model_state
return cls(app_models)
def __eq__(self, other):
if set(self.models.keys()) != set(other.models.keys()):
return False
if set(self.real_apps) != set(other.real_apps):
return False
return all(model == other.models[key] for key, model in self.models.items())
def __ne__(self, other):
return not (self == other)
def test_dangling_references_throw_error(self):
new_apps = Apps()
class Author(models.Model):
name = models.TextField()
class Meta:
app_label = "migrations"
apps = new_apps
class Publisher(models.Model):
name = models.TextField()
class Meta:
app_label = "migrations"
apps = new_apps
class Book(models.Model):
author = models.ForeignKey(Author, models.CASCADE)
publisher = models.ForeignKey(Publisher, models.CASCADE)
class Meta:
app_label = "migrations"
apps = new_apps
class Magazine(models.Model):
authors = models.ManyToManyField(Author)
class Meta:
app_label = "migrations"
apps = new_apps
# Make a valid ProjectState and render it
project_state = ProjectState()
project_state.add_model(ModelState.from_model(Author))
project_state.add_model(ModelState.from_model(Publisher))
project_state.add_model(ModelState.from_model(Book))
project_state.add_model(ModelState.from_model(Magazine))
self.assertEqual(len(project_state.apps.get_models()), 4)
# now make an invalid one with a ForeignKey
project_state = ProjectState()
project_state.add_model(ModelState.from_model(Book))
msg = (
"Unhandled pending operations for models:\n"
" migrations.author (referred to by fields: migrations.Book.author)\n"
" migrations.publisher (referred to by fields: migrations.Book.publisher)"
)
with self.assertRaisesMessage(ValueError, msg):
project_state.apps
# And another with ManyToManyField.
project_state = ProjectState()
project_state.add_model(ModelState.from_model(Magazine))
msg = (
"Unhandled pending operations for models:\n"
" migrations.author (referred to by fields: "
"migrations.Magazine.authors, migrations.Magazine_authors.author)")
with self.assertRaisesMessage(ValueError, msg):
project_state.apps
# And now with multiple models and multiple fields.
project_state.add_model(ModelState.from_model(Book))
msg = (
"Unhandled pending operations for models:\n"
" migrations.author (referred to by fields: migrations.Book.author, "
"migrations.Magazine.authors, migrations.Magazine_authors.author)\n"
" migrations.publisher (referred to by fields: migrations.Book.publisher)"
)
with self.assertRaisesMessage(ValueError, msg):
project_state.apps
class Meta:
# Disable auto loading of this model as we load it on our own
apps = Apps()
verbose_name = 'úñí©óðé µóðéø'
verbose_name_plural = 'úñí©óðé µóðéøß'
def test_create(self):
"""
Tests making a ProjectState from an Apps
"""
new_apps = Apps(["migrations"])
class Author(models.Model):
name = models.CharField(max_length=255)
bio = models.TextField()
age = models.IntegerField(blank=True, null=True)
class Meta:
app_label = "migrations"
apps = new_apps
unique_together = ["name", "bio"]
class AuthorProxy(Author):
class Meta:
app_label = "migrations"
apps = new_apps
proxy = True
ordering = ["name"]
class Book(models.Model):
title = models.CharField(max_length=1000)
author = models.ForeignKey(Author)
contributors = models.ManyToManyField(Author)
class Meta:
app_label = "migrations"
apps = new_apps
verbose_name = "tome"
db_table = "test_tome"
project_state = ProjectState.from_apps(new_apps)
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")
self.assertEqual(author_state.name, "Author")
self.assertEqual([x for x, y in author_state.fields],
["id", "name", "bio", "age"])
self.assertEqual(author_state.fields[1][1].max_length, 255)
self.assertEqual(author_state.fields[2][1].null, False)
self.assertEqual(author_state.fields[3][1].null, True)
self.assertEqual(author_state.options,
{"unique_together": {("name", "bio")}})
self.assertEqual(author_state.bases, (models.Model, ))
self.assertEqual(book_state.app_label, "migrations")
self.assertEqual(book_state.name, "Book")
self.assertEqual([x for x, y in book_state.fields],
["id", "title", "author", "contributors"])
self.assertEqual(book_state.fields[1][1].max_length, 1000)
self.assertEqual(book_state.fields[2][1].null, False)
self.assertEqual(book_state.fields[3][1].__class__.__name__,
"ManyToManyField")
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", ))
class Meta:
# Disable auto loading of this model as we load it on our own
apps = Apps()
class Meta:
apps = Apps()
app_label = "channels"
db_table = "django_channel_groups"
unique_together = [["group", "channel"]]
def _remake_table(self,
model,
create_fields=[],
delete_fields=[],
alter_fields=[],
override_uniques=None):
"""
Shortcut to transform a model from old_model into new_model
"""
# Work out the new fields dict / mapping
body = dict((f.name, f) for f in model._meta.local_fields)
# Since mapping might mix column names and default values,
# its values must be already quoted.
mapping = dict((f.column, self.quote_name(f.column))
for f in model._meta.local_fields)
# This maps field names (not columns) for things like unique_together
rename_mapping = {}
# If any of the new or altered fields is introducing a new PK,
# remove the old one
restore_pk_field = None
if any(f.primary_key
for f in create_fields) or any(n.primary_key
for o, n in alter_fields):
for name, field in list(body.items()):
if field.primary_key:
field.primary_key = False
restore_pk_field = field
if field.auto_created:
del body[name]
del mapping[field.column]
# Add in any created fields
for field in create_fields:
body[field.name] = field
# If there's a default, insert it into the copy map
if field.has_default():
mapping[field.column] = self.quote_value(
self.effective_default(field))
# Add in any altered fields
for (old_field, new_field) in alter_fields:
del body[old_field.name]
del mapping[old_field.column]
body[new_field.name] = new_field
mapping[new_field.column] = self.quote_name(old_field.column)
rename_mapping[old_field.name] = new_field.name
# Remove any deleted fields
for field in delete_fields:
del body[field.name]
del mapping[field.column]
# Remove any implicit M2M tables
if isinstance(
field,
ManyToManyField) and field.rel.through._meta.auto_created:
return self.delete_model(field.rel.through)
# Work inside a new app registry
apps = Apps()
# Provide isolated instances of the fields to the new model body
# Instantiating the new model with an alternate db_table will alter
# the internal references of some of the provided fields.
body = copy.deepcopy(body)
# Work out the new value of unique_together, taking renames into
# account
if override_uniques is None:
override_uniques = [[rename_mapping.get(n, n) for n in unique]
for unique in model._meta.unique_together]
# Construct a new model for the new state
meta_contents = {
'app_label': model._meta.app_label,
'db_table': model._meta.db_table + "__new",
'unique_together': override_uniques,
'apps': apps,
}
meta = type("Meta", tuple(), meta_contents)
body['Meta'] = meta
body['__module__'] = model.__module__
temp_model = type(model._meta.object_name, model.__bases__, body)
# Create a new table with that format. We remove things from the
# deferred SQL that match our table name, too
self.deferred_sql = [
x for x in self.deferred_sql if model._meta.db_table not in x
]
self.create_model(temp_model)
# Copy data from the old table
field_maps = list(mapping.items())
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
self.quote_name(temp_model._meta.db_table),
', '.join(self.quote_name(x) for x, y in field_maps),
', '.join(y for x, y in field_maps),
self.quote_name(model._meta.db_table),
))
# Delete the old table
self.delete_model(model, handle_autom2m=False)
# Rename the new to the old
self.alter_db_table(temp_model, temp_model._meta.db_table,
model._meta.db_table)
# Run deferred SQL on correct table
for sql in self.deferred_sql:
self.execute(
sql.replace(temp_model._meta.db_table, model._meta.db_table))
self.deferred_sql = []
# Fix any PK-removed field
if restore_pk_field:
restore_pk_field.primary_key = True
def _remake_table(self,
model,
create_field=None,
delete_field=None,
alter_field=None):
"""
Shortcut to transform a model from old_model into new_model
This follows the correct procedure to perform non-rename or column
addition operations based on SQLite's documentation
https://www.sqlite.org/lang_altertable.html#caution
The essential steps are:
1. Create a table with the updated definition called "new__app_model"
2. Copy the data from the existing "app_model" table to the new table
3. Drop the "app_model" table
4. Rename the "new__app_model" table to "app_model"
5. Restore any index of the previous "app_model" table.
"""
# Self-referential fields must be recreated rather than copied from
# the old model to ensure their remote_field.field_name doesn't refer
# to an altered field.
def is_self_referential(f):
return f.is_relation and f.remote_field.model is model
# Work out the new fields dict / mapping
body = {
f.name: f.clone() if is_self_referential(f) else f
for f in model._meta.local_concrete_fields
}
# Since mapping might mix column names and default values,
# its values must be already quoted.
mapping = {
f.column: self.quote_name(f.column)
for f in model._meta.local_concrete_fields
}
# This maps field names (not columns) for things like unique_together
rename_mapping = {}
# If any of the new or altered fields is introducing a new PK,
# remove the old one
restore_pk_field = None
if getattr(create_field, 'primary_key', False) or (
alter_field and getattr(alter_field[1], 'primary_key', False)):
for name, field in list(body.items()):
if field.primary_key:
field.primary_key = False
restore_pk_field = field
if field.auto_created:
del body[name]
del mapping[field.column]
# Add in any created fields
if create_field:
body[create_field.name] = create_field
# Choose a default and insert it into the copy map
if not create_field.many_to_many and create_field.concrete:
mapping[create_field.column] = self.quote_value(
self.effective_default(create_field))
# Add in any altered fields
if alter_field:
old_field, new_field = alter_field
body.pop(old_field.name, None)
mapping.pop(old_field.column, None)
body[new_field.name] = new_field
if old_field.null and not new_field.null:
case_sql = "coalesce(%(col)s, %(default)s)" % {
'col': self.quote_name(old_field.column),
'default': self.quote_value(
self.effective_default(new_field))
}
mapping[new_field.column] = case_sql
else:
mapping[new_field.column] = self.quote_name(old_field.column)
rename_mapping[old_field.name] = new_field.name
# Remove any deleted fields
if delete_field:
del body[delete_field.name]
del mapping[delete_field.column]
# Remove any implicit M2M tables
if delete_field.many_to_many and delete_field.remote_field.through._meta.auto_created:
return self.delete_model(delete_field.remote_field.through)
# Work inside a new app registry
apps = Apps()
# Work out the new value of unique_together, taking renames into
# account
unique_together = [[rename_mapping.get(n, n) for n in unique]
for unique in model._meta.unique_together]
# Work out the new value for index_together, taking renames into
# account
index_together = [[rename_mapping.get(n, n) for n in index]
for index in model._meta.index_together]
indexes = model._meta.indexes
if delete_field:
indexes = [
index for index in indexes
if delete_field.name not in index.fields
]
constraints = list(model._meta.constraints)
# Provide isolated instances of the fields to the new model body so
# that the existing model's internals aren't interfered with when
# the dummy model is constructed.
body_copy = copy.deepcopy(body)
# Construct a new model with the new fields to allow self referential
# primary key to resolve to. This model won't ever be materialized as a
# table and solely exists for foreign key reference resolution purposes.
# This wouldn't be required if the schema editor was operating on model
# states instead of rendered models.
meta_contents = {
'app_label': model._meta.app_label,
'db_table': model._meta.db_table,
'unique_together': unique_together,
'index_together': index_together,
'indexes': indexes,
'constraints': constraints,
'apps': apps,
}
meta = type("Meta", (), meta_contents)
body_copy['Meta'] = meta
body_copy['__module__'] = model.__module__
type(model._meta.object_name, model.__bases__, body_copy)
# Construct a model with a renamed table name.
body_copy = copy.deepcopy(body)
meta_contents = {
'app_label': model._meta.app_label,
'db_table': 'new__%s' % strip_quotes(model._meta.db_table),
'unique_together': unique_together,
'index_together': index_together,
'indexes': indexes,
'constraints': constraints,
'apps': apps,
}
meta = type("Meta", (), meta_contents)
body_copy['Meta'] = meta
body_copy['__module__'] = model.__module__
new_model = type('New%s' % model._meta.object_name, model.__bases__,
body_copy)
# Create a new table with the updated schema.
self.create_model(new_model)
# Copy data from the old table into the new table
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
self.quote_name(new_model._meta.db_table),
', '.join(self.quote_name(x) for x in mapping),
', '.join(mapping.values()),
self.quote_name(model._meta.db_table),
))
# Delete the old table to make way for the new
self.delete_model(model, handle_autom2m=False)
# Rename the new table to take way for the old
self.alter_db_table(
new_model,
new_model._meta.db_table,
model._meta.db_table,
disable_constraints=False,
)
# Run deferred SQL on correct table
for sql in self.deferred_sql:
self.execute(sql)
self.deferred_sql = []
# Fix any PK-removed field
if restore_pk_field:
restore_pk_field.primary_key = True
def _remake_table(self,
model,
create_field=None,
delete_field=None,
alter_field=None):
"""
Shortcut to transform a model from old_model into new_model
The essential steps are:
1. rename the model's existing table, e.g. "app_model" to "app_model__old"
2. create a table with the updated definition called "app_model"
3. copy the data from the old renamed table to the new table
4. delete the "app_model__old" table
"""
# Self-referential fields must be recreated rather than copied from
# the old model to ensure their remote_field.field_name doesn't refer
# to an altered field.
def is_self_referential(f):
return f.is_relation and f.remote_field.model is model
# Work out the new fields dict / mapping
body = {
f.name: f.clone() if is_self_referential(f) else f
for f in model._meta.local_concrete_fields
}
# Since mapping might mix column names and default values,
# its values must be already noted.
mapping = {
f.column: self.note_name(f.column)
for f in model._meta.local_concrete_fields
}
# This maps field names (not columns) for things like unique_together
rename_mapping = {}
# If any of the new or altered fields is introducing a new PK,
# remove the old one
restore_pk_field = None
if getattr(create_field, 'primary_key', False) or (
alter_field and getattr(alter_field[1], 'primary_key', False)):
for name, field in list(body.items()):
if field.primary_key:
field.primary_key = False
restore_pk_field = field
if field.auto_created:
del body[name]
del mapping[field.column]
# Add in any created fields
if create_field:
body[create_field.name] = create_field
# Choose a default and insert it into the copy map
if not create_field.many_to_many and create_field.concrete:
mapping[create_field.column] = self.note_value(
self.effective_default(create_field))
# Add in any altered fields
if alter_field:
old_field, new_field = alter_field
body.pop(old_field.name, None)
mapping.pop(old_field.column, None)
body[new_field.name] = new_field
if old_field.null and not new_field.null:
case_sql = "coalesce(%(col)s, %(default)s)" % {
'col': self.note_name(old_field.column),
'default': self.note_value(
self.effective_default(new_field))
}
mapping[new_field.column] = case_sql
else:
mapping[new_field.column] = self.note_name(old_field.column)
rename_mapping[old_field.name] = new_field.name
# Remove any deleted fields
if delete_field:
del body[delete_field.name]
del mapping[delete_field.column]
# Remove any implicit M2M tables
if delete_field.many_to_many and delete_field.remote_field.through._meta.auto_created:
return self.delete_model(delete_field.remote_field.through)
# Work inside a new app registry
apps = Apps()
# Provide isolated instances of the fields to the new model body so
# that the existing model's internals aren't interfered with when
# the dummy model is constructed.
body = copy.deepcopy(body)
# Work out the new value of unique_together, taking renames into
# account
unique_together = [[rename_mapping.get(n, n) for n in unique]
for unique in model._meta.unique_together]
# Work out the new value for index_together, taking renames into
# account
index_together = [[rename_mapping.get(n, n) for n in index]
for index in model._meta.index_together]
indexes = model._meta.indexes
if delete_field:
indexes = [
index for index in indexes
if delete_field.name not in index.fields
]
# Construct a new model for the new state
meta_contents = {
'app_label': model._meta.app_label,
'db_table': model._meta.db_table,
'unique_together': unique_together,
'index_together': index_together,
'indexes': indexes,
'apps': apps,
}
meta = type("Meta", tuple(), meta_contents)
body['Meta'] = meta
body['__module__'] = model.__module__
temp_model = type(model._meta.object_name, model.__bases__, body)
# We need to modify model._meta.db_table, but everything explodes
# if the change isn't reversed before the end of this method. This
# context manager helps us avoid that situation.
@contextlib.contextmanager
def altered_table_name(model, temporary_table_name):
original_table_name = model._meta.db_table
model._meta.db_table = temporary_table_name
yield
model._meta.db_table = original_table_name
with altered_table_name(model, model._meta.db_table + "__old"):
# Rename the old table to make way for the new
self.alter_db_table(model, temp_model._meta.db_table,
model._meta.db_table)
# Create a new table with the updated schema. We remove things
# from the deferred SQL that match our table name, too
self.deferred_sql = [
x for x in self.deferred_sql
if temp_model._meta.db_table not in x
]
self.create_model(temp_model)
# Copy data from the old table into the new table
field_maps = list(mapping.items())
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
self.note_name(temp_model._meta.db_table),
', '.join(self.note_name(x) for x, y in field_maps),
', '.join(y for x, y in field_maps),
self.note_name(model._meta.db_table),
))
# Delete the old table
self.delete_model(model, handle_autom2m=False)
# Run deferred SQL on correct table
for sql in self.deferred_sql:
self.execute(sql)
self.deferred_sql = []
# Fix any PK-removed field
if restore_pk_field:
restore_pk_field.primary_key = True
def test_wait_for_apps_ready_without_exception(self):
app_reg = Apps()
app_reg.ready_event.set()
thread = mock.MagicMock()
thread.is_alive.return_value = True
self.assertTrue(self.reloader.wait_for_apps_ready(app_reg, thread))
def render(self,
include_real=None,
ignore_swappable=False,
skip_cache=False):
"Turns the project state into actual models in a new Apps"
if self.apps is None or skip_cache:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
# FKs/M2Ms from real apps are also not included as they just
# mess things up with partial states (due to lack of dependencies)
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(
ModelState.from_model(model, exclude_rels=True))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label
for model_state in self.models.values())
self.apps = Apps([
AppConfigStub(label)
for label in sorted(self.real_apps + list(app_labels))
])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError(
"Cannot resolve bases for %r\nThis can happen if you are inheriting models from an "
"app with migrations (e.g. contrib.auth)\n in an app with no migrations; see "
"https://docs.djangoproject.com/en/1.7/topics/migrations/#dependencies "
"for more" % new_unrendered_models)
unrendered_models = new_unrendered_models
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items(
):
try:
model = self.apps.get_model(lookup_model[0],
lookup_model[1])
except LookupError:
app_label = "%s.%s" % (lookup_model[0],
lookup_model[1])
if app_label == settings.AUTH_USER_MODEL and ignore_swappable:
continue
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
msg = "Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}"
raise ValueError(
msg.format(field=operations[0][1],
model=lookup_model))
else:
do_pending_lookups(model)
try:
return self.apps
finally:
if skip_cache:
self.apps = None
class Meta:
app_label = "migrations"
apps = Apps()
from django.apps.registry import Apps
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
# Because we want to test creation and deletion of these as separate things,
# these models are all inserted into a separate Apps so the main test
# runner doesn't migrate them.
new_apps = Apps()
class Author(models.Model):
name = models.CharField(max_length=255)
height = models.PositiveIntegerField(null=True, blank=True)
class Meta:
apps = new_apps
class AuthorWithM2M(models.Model):
name = models.CharField(max_length=255)
class Meta:
apps = new_apps
class Book(models.Model):
author = models.ForeignKey(Author)
title = models.CharField(max_length=100, db_index=True)
pub_date = models.DateTimeField()
def enable(self):
self.old_apps = Options.default_apps
apps = Apps(self.installed_apps)
setattr(Options, 'default_apps', apps)
return apps
class ProjectState(object):
"""
Represents the entire project's overall state.
This is the item that is passed around - we do it here rather than at the
app level so that cross-app FKs/etc. resolve properly.
"""
def __init__(self, models=None):
self.models = models or {}
self.apps = None
def add_model_state(self, model_state):
self.models[(model_state.app_label, model_state.name.lower())] = model_state
def clone(self):
"Returns an exact copy of this ProjectState"
return ProjectState(
models=dict((k, v.clone()) for k, v in self.models.items())
)
def render(self):
"Turns the project state into actual models in a new Apps"
if self.apps is None:
self.apps = Apps()
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label for model_state in self.models.values())
app_configs = [AppConfigStub(label) for label in sorted(app_labels)]
self.apps.populate_apps(app_configs)
self.apps.populate_models()
# 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.apps)
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.apps
@classmethod
def from_apps(cls, apps):
"Takes in an Apps and returns a ProjectState matching it"
app_models = {}
for model in apps.get_models():
model_state = ModelState.from_model(model)
app_models[(model_state.app_label, model_state.name.lower())] = model_state
return cls(app_models)
def __eq__(self, other):
if set(self.models.keys()) != set(other.models.keys()):
return False
return all(model == other.models[key] for key, model in self.models.items())
def __ne__(self, other):
return not (self == other)
class Meta:
apps = Apps()
app_label = "migrations"
db_table = "django_migrations"
def test_singleton_master(self):
"""
Ensures that only one master registry can exist.
"""
with self.assertRaises(RuntimeError):
Apps(installed_apps=None)
class ProjectState(object):
"""
Represents the entire project's overall state.
This is the item that is passed around - we do it here rather than at the
app level so that cross-app FKs/etc. resolve properly.
"""
def __init__(self, models=None, real_apps=None):
self.models = models or {}
self.apps = None
# Apps to include from main registry, usually unmigrated ones
self.real_apps = real_apps or []
def add_model_state(self, model_state):
self.models[(model_state.app_label,
model_state.name.lower())] = model_state
def clone(self):
"Returns an exact copy of this ProjectState"
return ProjectState(
models=dict((k, v.clone()) for k, v in self.models.items()),
real_apps=self.real_apps,
)
def render(self, include_real=None, ignore_swappable=False):
"Turns the project state into actual models in a new Apps"
if self.apps is None:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(ModelState.from_model(model))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label
for model_state in self.models.values())
self.apps = Apps([
AppConfigStub(label)
for label in sorted(self.real_apps + list(app_labels))
])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
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
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items(
):
try:
model = self.apps.get_model(lookup_model[0],
lookup_model[1])
except LookupError:
if "%s.%s" % (
lookup_model[0], lookup_model[1]
) == settings.AUTH_USER_MODEL and ignore_swappable:
continue
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
raise ValueError(
"Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}"
.format(
field=operations[0][1],
model=lookup_model,
))
else:
do_pending_lookups(model)
return self.apps
@classmethod
def from_apps(cls, apps):
"Takes in an Apps and returns a ProjectState matching it"
app_models = {}
for model in apps.get_models():
model_state = ModelState.from_model(model)
app_models[(model_state.app_label,
model_state.name.lower())] = model_state
return cls(app_models)
def __eq__(self, other):
if set(self.models.keys()) != set(other.models.keys()):
return False
if set(self.real_apps) != set(other.real_apps):
return False
return all(model == other.models[key]
for key, model in self.models.items())
def __ne__(self, other):
return not (self == other)
def test_add_relations(self):
"""
#24573 - Adding relations to existing models should reload the
referenced models too.
"""
new_apps = Apps()
class A(models.Model):
class Meta:
app_label = 'something'
apps = new_apps
class B(A):
class Meta:
app_label = 'something'
apps = new_apps
class C(models.Model):
class Meta:
app_label = 'something'
apps = new_apps
project_state = ProjectState()
project_state.add_model(ModelState.from_model(A))
project_state.add_model(ModelState.from_model(B))
project_state.add_model(ModelState.from_model(C))
project_state.apps # We need to work with rendered models
old_state = project_state.clone()
model_a_old = old_state.apps.get_model('something', 'A')
model_b_old = old_state.apps.get_model('something', 'B')
model_c_old = old_state.apps.get_model('something', 'C')
# Check that the relations between the old models are correct
self.assertIs(
model_a_old._meta.get_field('b').related_model, model_b_old)
self.assertIs(
model_b_old._meta.get_field('a_ptr').related_model, model_a_old)
operation = AddField(
'c', 'to_a',
models.OneToOneField(
'something.A',
models.CASCADE,
related_name='from_c',
))
operation.state_forwards('something', project_state)
model_a_new = project_state.apps.get_model('something', 'A')
model_b_new = project_state.apps.get_model('something', 'B')
model_c_new = project_state.apps.get_model('something', 'C')
# Check that all models have changed
self.assertIsNot(model_a_old, model_a_new)
self.assertIsNot(model_b_old, model_b_new)
self.assertIsNot(model_c_old, model_c_new)
# Check that the relations between the old models still hold
self.assertIs(
model_a_old._meta.get_field('b').related_model, model_b_old)
self.assertIs(
model_b_old._meta.get_field('a_ptr').related_model, model_a_old)
# Check that the relations between the new models correct
self.assertIs(
model_a_new._meta.get_field('b').related_model, model_b_new)
self.assertIs(
model_b_new._meta.get_field('a_ptr').related_model, model_a_new)
self.assertIs(
model_a_new._meta.get_field('from_c').related_model, model_c_new)
self.assertIs(
model_c_new._meta.get_field('to_a').related_model, model_a_new)
class ProjectState(object):
"""
Represents the entire project's overall state.
This is the item that is passed around - we do it here rather than at the
app level so that cross-app FKs/etc. resolve properly.
"""
def __init__(self, models=None, real_apps=None):
self.models = models or {}
self.apps = None
# Apps to include from main registry, usually unmigrated ones
self.real_apps = real_apps or []
def add_model_state(self, model_state):
self.models[(model_state.app_label, model_state.name.lower())] = model_state
def clone(self):
"Returns an exact copy of this ProjectState"
return ProjectState(
models=dict((k, v.clone()) for k, v in self.models.items()),
real_apps=self.real_apps,
)
def render(self, include_real=None, ignore_swappable=False, skip_cache=False):
"Turns the project state into actual models in a new Apps"
if self.apps is None or skip_cache:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
# FKs/M2Ms from real apps are also not included as they just
# mess things up with partial states (due to lack of dependencies)
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(ModelState.from_model(model, exclude_rels=True))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label for model_state in self.models.values())
self.apps = Apps([AppConfigStub(label) for label in sorted(self.real_apps + list(app_labels))])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError("Cannot resolve bases for %r\nThis can happen if you are inheriting models from an app with migrations (e.g. contrib.auth)\n in an app with no migrations; see https://docs.djangoproject.com/en/1.7/topics/migrations/#dependencies for more" % new_unrendered_models)
unrendered_models = new_unrendered_models
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items():
try:
model = self.apps.get_model(lookup_model[0], lookup_model[1])
except LookupError:
if "%s.%s" % (lookup_model[0], lookup_model[1]) == settings.AUTH_USER_MODEL and ignore_swappable:
continue
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
raise ValueError("Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}".format(
field=operations[0][1],
model=lookup_model,
))
else:
do_pending_lookups(model)
try:
return self.apps
finally:
if skip_cache:
self.apps = None
@classmethod
def from_apps(cls, apps):
"Takes in an Apps and returns a ProjectState matching it"
app_models = {}
for model in apps.get_models(include_swapped=True):
model_state = ModelState.from_model(model)
app_models[(model_state.app_label, model_state.name.lower())] = model_state
return cls(app_models)
def __eq__(self, other):
if set(self.models.keys()) != set(other.models.keys()):
return False
if set(self.real_apps) != set(other.real_apps):
return False
return all(model == other.models[key] for key, model in self.models.items())
def __ne__(self, other):
return not (self == other)
def render(self, include_real=None, ignore_swappable=False):
"Turns the project state into actual models in a new Apps"
if self.apps is None:
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
real_models = []
for app_label in self.real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
real_models.append(ModelState.from_model(model))
# Populate the app registry with a stub for each application.
app_labels = set(model_state.app_label
for model_state in self.models.values())
self.apps = Apps([
AppConfigStub(label)
for label in sorted(self.real_apps + list(app_labels))
])
# 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()) + real_models
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self.apps)
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
# make sure apps has no dangling references
if self.apps._pending_lookups:
# There's some lookups left. See if we can first resolve them
# ourselves - sometimes fields are added after class_prepared is sent
for lookup_model, operations in self.apps._pending_lookups.items(
):
try:
model = self.apps.get_model(lookup_model[0],
lookup_model[1])
except LookupError:
if "%s.%s" % (
lookup_model[0], lookup_model[1]
) == settings.AUTH_USER_MODEL and ignore_swappable:
continue
# Raise an error with a best-effort helpful message
# (only for the first issue). Error message should look like:
# "ValueError: Lookup failed for model referenced by
# field migrations.Book.author: migrations.Author"
raise ValueError(
"Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}"
.format(
field=operations[0][1],
model=lookup_model,
))
else:
do_pending_lookups(model)
return self.apps
