Python django.db.router.allow_migrate_model() Examples

def test_migrate_selection(self):
        "Synchronization behavior is predictable"

        self.assertTrue(router.allow_migrate_model('default', User))
        self.assertTrue(router.allow_migrate_model('default', Book))

        self.assertTrue(router.allow_migrate_model('other', User))
        self.assertTrue(router.allow_migrate_model('other', Book))

        with override_settings(DATABASE_ROUTERS=[TestRouter(), AuthRouter()]):
            # Add the auth router to the chain. TestRouter is a universal
            # synchronizer, so it should have no effect.
            self.assertTrue(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book))

            self.assertTrue(router.allow_migrate_model('other', User))
            self.assertTrue(router.allow_migrate_model('other', Book))

        with override_settings(DATABASE_ROUTERS=[AuthRouter(), TestRouter()]):
            # Now check what happens if the router order is reversed.
            self.assertFalse(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book))

            self.assertTrue(router.allow_migrate_model('other', User))
            self.assertTrue(router.allow_migrate_model('other', Book)) 

def test_migrate_selection(self):
        "Synchronization behavior is predictable"

        self.assertTrue(router.allow_migrate_model('default', User))
        self.assertTrue(router.allow_migrate_model('default', Book))

        self.assertTrue(router.allow_migrate_model('other', User))
        self.assertTrue(router.allow_migrate_model('other', Book))

        with override_settings(DATABASE_ROUTERS=[TestRouter(), AuthRouter()]):
            # Add the auth router to the chain. TestRouter is a universal
            # synchronizer, so it should have no effect.
            self.assertTrue(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book))

            self.assertTrue(router.allow_migrate_model('other', User))
            self.assertTrue(router.allow_migrate_model('other', Book))

        with override_settings(DATABASE_ROUTERS=[AuthRouter(), TestRouter()]):
            # Now check what happens if the router order is reversed.
            self.assertFalse(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book))

            self.assertTrue(router.allow_migrate_model('other', User))
            self.assertTrue(router.allow_migrate_model('other', Book)) 

def test_migrate_selection(self):
        "Synchronization behavior is predictable"

        self.assertTrue(router.allow_migrate_model('default', User))
        self.assertTrue(router.allow_migrate_model('default', Book))

        self.assertTrue(router.allow_migrate_model('other', User))
        self.assertTrue(router.allow_migrate_model('other', Book))

        with override_settings(DATABASE_ROUTERS=[TestRouter(), AuthRouter()]):
            # Add the auth router to the chain. TestRouter is a universal
            # synchronizer, so it should have no effect.
            self.assertTrue(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book))

            self.assertTrue(router.allow_migrate_model('other', User))
            self.assertTrue(router.allow_migrate_model('other', Book))

        with override_settings(DATABASE_ROUTERS=[AuthRouter(), TestRouter()]):
            # Now check what happens if the router order is reversed.
            self.assertFalse(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book))

            self.assertTrue(router.allow_migrate_model('other', User))
            self.assertTrue(router.allow_migrate_model('other', Book)) 

def allow_migrate_model(self, connection_alias, model):
        """
        Returns if we're allowed to migrate the model.

        This is a thin wrapper around router.allow_migrate_model() that
        preemptively rejects any proxy, swapped out, or unmanaged model.
        """
        if not model._meta.can_migrate(connection_alias):
            return False

        return router.allow_migrate_model(connection_alias, model) 

def test_partial_router(self):
        "A router can choose to implement a subset of methods"
        dive = Book.objects.using('other').create(title="Dive into Python",
                                                  published=datetime.date(2009, 5, 4))

        # First check the baseline behavior.

        self.assertEqual(router.db_for_read(User), 'other')
        self.assertEqual(router.db_for_read(Book), 'other')

        self.assertEqual(router.db_for_write(User), 'default')
        self.assertEqual(router.db_for_write(Book), 'default')

        self.assertTrue(router.allow_relation(dive, dive))

        self.assertTrue(router.allow_migrate_model('default', User))
        self.assertTrue(router.allow_migrate_model('default', Book))

        with override_settings(DATABASE_ROUTERS=[WriteRouter(), AuthRouter(), TestRouter()]):
            self.assertEqual(router.db_for_read(User), 'default')
            self.assertEqual(router.db_for_read(Book), 'other')

            self.assertEqual(router.db_for_write(User), 'writer')
            self.assertEqual(router.db_for_write(Book), 'writer')

            self.assertTrue(router.allow_relation(dive, dive))

            self.assertFalse(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book)) 

def test_partial_router(self):
        "A router can choose to implement a subset of methods"
        dive = Book.objects.using('other').create(title="Dive into Python",
                                                  published=datetime.date(2009, 5, 4))

        # First check the baseline behavior.

        self.assertEqual(router.db_for_read(User), 'other')
        self.assertEqual(router.db_for_read(Book), 'other')

        self.assertEqual(router.db_for_write(User), 'default')
        self.assertEqual(router.db_for_write(Book), 'default')

        self.assertTrue(router.allow_relation(dive, dive))

        self.assertTrue(router.allow_migrate_model('default', User))
        self.assertTrue(router.allow_migrate_model('default', Book))

        with override_settings(DATABASE_ROUTERS=[WriteRouter(), AuthRouter(), TestRouter()]):
            self.assertEqual(router.db_for_read(User), 'default')
            self.assertEqual(router.db_for_read(Book), 'other')

            self.assertEqual(router.db_for_write(User), 'writer')
            self.assertEqual(router.db_for_write(Book), 'writer')

            self.assertTrue(router.allow_relation(dive, dive))

            self.assertFalse(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book)) 

def test_partial_router(self):
        "A router can choose to implement a subset of methods"
        dive = Book.objects.using('other').create(title="Dive into Python",
                                                  published=datetime.date(2009, 5, 4))

        # First check the baseline behavior.

        self.assertEqual(router.db_for_read(User), 'other')
        self.assertEqual(router.db_for_read(Book), 'other')

        self.assertEqual(router.db_for_write(User), 'default')
        self.assertEqual(router.db_for_write(Book), 'default')

        self.assertTrue(router.allow_relation(dive, dive))

        self.assertTrue(router.allow_migrate_model('default', User))
        self.assertTrue(router.allow_migrate_model('default', Book))

        with override_settings(DATABASE_ROUTERS=[WriteRouter(), AuthRouter(), TestRouter()]):
            self.assertEqual(router.db_for_read(User), 'default')
            self.assertEqual(router.db_for_read(Book), 'other')

            self.assertEqual(router.db_for_write(User), 'writer')
            self.assertEqual(router.db_for_write(Book), 'writer')

            self.assertTrue(router.allow_relation(dive, dive))

            self.assertFalse(router.allow_migrate_model('default', User))
            self.assertTrue(router.allow_migrate_model('default', Book)) 

def serialize_db_to_string(self):
        """
        Serializes all data in the database into a JSON string.
        Designed only for test runner usage; will not handle large
        amounts of data.
        """
        # Build list of all apps to serialize
        from django.db.migrations.loader import MigrationLoader
        loader = MigrationLoader(self.connection)
        app_list = []
        for app_config in apps.get_app_configs():
            if (
                app_config.models_module is not None and
                app_config.label in loader.migrated_apps and
                app_config.name not in settings.TEST_NON_SERIALIZED_APPS
            ):
                app_list.append((app_config, None))

        # Make a function to iteratively return every object
        def get_objects():
            for model in serializers.sort_dependencies(app_list):
                if (model._meta.can_migrate(self.connection) and
                        router.allow_migrate_model(self.connection.alias, model)):
                    queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
                    for obj in queryset.iterator():
                        yield obj
        # Serialize to a string
        out = StringIO()
        serializers.serialize("json", get_objects(), indent=None, stream=out)
        return out.getvalue() 

def allow_migrate_model(self, connection_alias, model):
        """
        Returns if we're allowed to migrate the model.

        This is a thin wrapper around router.allow_migrate_model() that
        preemptively rejects any proxy, swapped out, or unmanaged model.
        """
        if not model._meta.can_migrate(connection_alias):
            return False

        return router.allow_migrate_model(connection_alias, model) 

def create_default_site(app_config, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, **kwargs):
    try:
        Site = apps.get_model('sites', 'Site')
    except LookupError:
        return

    if not router.allow_migrate_model(using, Site):
        return

    if not Site.objects.using(using).exists():
        # The default settings set SITE_ID = 1, and some tests in Django's test
        # suite rely on this value. However, if database sequences are reused
        # (e.g. in the test suite after flush/syncdb), it isn't guaranteed that
        # the next id will be 1, so we coerce it. See #15573 and #16353. This
        # can also crop up outside of tests - see #15346.
        if verbosity >= 2:
            print("Creating example.com Site object")
        Site(pk=getattr(settings, 'SITE_ID', 1), domain="example.com", name="example.com").save(using=using)

        # We set an explicit pk instead of relying on auto-incrementation,
        # so we need to reset the database sequence. See #17415.
        sequence_sql = connections[using].ops.sequence_reset_sql(no_style(), [Site])
        if sequence_sql:
            if verbosity >= 2:
                print("Resetting sequence")
            with connections[using].cursor() as cursor:
                for command in sequence_sql:
                    cursor.execute(command) 

def serialize_db_to_string(self):
        """
        Serializes all data in the database into a JSON string.
        Designed only for test runner usage; will not handle large
        amounts of data.
        """
        # Build list of all apps to serialize
        from django.db.migrations.loader import MigrationLoader
        loader = MigrationLoader(self.connection)
        app_list = []
        for app_config in apps.get_app_configs():
            if (
                app_config.models_module is not None and
                app_config.label in loader.migrated_apps and
                app_config.name not in settings.TEST_NON_SERIALIZED_APPS
            ):
                app_list.append((app_config, None))

        # Make a function to iteratively return every object
        def get_objects():
            for model in serializers.sort_dependencies(app_list):
                if (model._meta.can_migrate(self.connection) and
                        router.allow_migrate_model(self.connection.alias, model)):
                    queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
                    for obj in queryset.iterator():
                        yield obj
        # Serialize to a string
        out = StringIO()
        serializers.serialize("json", get_objects(), indent=None, stream=out)
        return out.getvalue() 

def allow_migrate_model(self, connection_alias, model):
        """
        Returns if we're allowed to migrate the model.

        This is a thin wrapper around router.allow_migrate_model() that
        preemptively rejects any proxy, swapped out, or unmanaged model.
        """
        if model._meta.proxy or model._meta.swapped or not model._meta.managed:
            return False

        return router.allow_migrate_model(connection_alias, model) 

def serialize_db_to_string(self):
        """
        Serializes all data in the database into a JSON string.
        Designed only for test runner usage; will not handle large
        amounts of data.
        """
        # Build list of all apps to serialize
        from django.db.migrations.loader import MigrationLoader
        loader = MigrationLoader(self.connection)
        app_list = []
        for app_config in apps.get_app_configs():
            if (
                app_config.models_module is not None and
                app_config.label in loader.migrated_apps and
                app_config.name not in settings.TEST_NON_SERIALIZED_APPS
            ):
                app_list.append((app_config, None))

        # Make a function to iteratively return every object
        def get_objects():
            for model in serializers.sort_dependencies(app_list):
                if (model._meta.can_migrate(self.connection) and
                        router.allow_migrate_model(self.connection.alias, model)):
                    queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
                    for obj in queryset.iterator():
                        yield obj
        # Serialize to a string
        out = StringIO()
        serializers.serialize("json", get_objects(), indent=None, stream=out)
        return out.getvalue() 

def allow_migrate_model(self, connection_alias, model):
        """
        Returns if we're allowed to migrate the model.

        This is a thin wrapper around router.allow_migrate_model() that
        preemptively rejects any proxy, swapped out, or unmanaged model.
        """
        if not model._meta.can_migrate(connection_alias):
            return False

        return router.allow_migrate_model(connection_alias, model) 

def serialize_db_to_string(self):
        """
        Serialize all data in the database into a JSON string.
        Designed only for test runner usage; will not handle large
        amounts of data.
        """
        # Build list of all apps to serialize
        from django.db.migrations.loader import MigrationLoader
        loader = MigrationLoader(self.connection)
        app_list = []
        for app_config in apps.get_app_configs():
            if (
                app_config.models_module is not None and
                app_config.label in loader.migrated_apps and
                app_config.name not in settings.TEST_NON_SERIALIZED_APPS
            ):
                app_list.append((app_config, None))

        # Make a function to iteratively return every object
        def get_objects():
            for model in serializers.sort_dependencies(app_list):
                if (model._meta.can_migrate(self.connection) and
                        router.allow_migrate_model(self.connection.alias, model)):
                    queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
                    yield from queryset.iterator()
        # Serialize to a string
        out = StringIO()
        serializers.serialize("json", get_objects(), indent=None, stream=out)
        return out.getvalue() 

def allow_migrate_model(self, connection_alias, model):
        """
        Return whether or not a model may be migrated.

        This is a thin wrapper around router.allow_migrate_model() that
        preemptively rejects any proxy, swapped out, or unmanaged model.
        """
        if not model._meta.can_migrate(connection_alias):
            return False

        return router.allow_migrate_model(connection_alias, model) 

def serialize_db_to_string(self):
        """
        Serialize all data in the database into a JSON string.
        Designed only for test runner usage; will not handle large
        amounts of data.
        """
        # Build list of all apps to serialize
        from django.db.migrations.loader import MigrationLoader
        loader = MigrationLoader(self.connection)
        app_list = []
        for app_config in apps.get_app_configs():
            if (
                app_config.models_module is not None and
                app_config.label in loader.migrated_apps and
                app_config.name not in settings.TEST_NON_SERIALIZED_APPS
            ):
                app_list.append((app_config, None))

        # Make a function to iteratively return every object
        def get_objects():
            for model in serializers.sort_dependencies(app_list):
                if (model._meta.can_migrate(self.connection) and
                        router.allow_migrate_model(self.connection.alias, model)):
                    queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
                    yield from queryset.iterator()
        # Serialize to a string
        out = StringIO()
        serializers.serialize("json", get_objects(), indent=None, stream=out)
        return out.getvalue() 

def allow_migrate_model(self, connection_alias, model):
        """
        Return wether or not a model may be migrated.

        This is a thin wrapper around router.allow_migrate_model() that
        preemptively rejects any proxy, swapped out, or unmanaged model.
        """
        if not model._meta.can_migrate(connection_alias):
            return False

        return router.allow_migrate_model(connection_alias, model) 

def create_default_site(app_config, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, **kwargs):
    try:
        Site = apps.get_model('sites', 'Site')
    except LookupError:
        return

    if not router.allow_migrate_model(using, Site):
        return

    if not Site.objects.using(using).exists():
        # The default settings set SITE_ID = 1, and some tests in Django's test
        # suite rely on this value. However, if database sequences are reused
        # (e.g. in the test suite after flush/syncdb), it isn't guaranteed that
        # the next id will be 1, so we coerce it. See #15573 and #16353. This
        # can also crop up outside of tests - see #15346.
        if verbosity >= 2:
            print("Creating example.com Site object")
        Site(pk=getattr(settings, 'SITE_ID', 1), domain="example.com", name="example.com").save(using=using)

        # We set an explicit pk instead of relying on auto-incrementation,
        # so we need to reset the database sequence. See #17415.
        sequence_sql = connections[using].ops.sequence_reset_sql(no_style(), [Site])
        if sequence_sql:
            if verbosity >= 2:
                print("Resetting sequence")
            with connections[using].cursor() as cursor:
                for command in sequence_sql:
                    cursor.execute(command) 

def serialize_db_to_string(self):
        """
        Serializes all data in the database into a JSON string.
        Designed only for test runner usage; will not handle large
        amounts of data.
        """
        # Build list of all apps to serialize
        from django.db.migrations.loader import MigrationLoader
        loader = MigrationLoader(self.connection)
        app_list = []
        for app_config in apps.get_app_configs():
            if (
                app_config.models_module is not None and
                app_config.label in loader.migrated_apps and
                app_config.name not in settings.TEST_NON_SERIALIZED_APPS
            ):
                app_list.append((app_config, None))

        # Make a function to iteratively return every object
        def get_objects():
            for model in serializers.sort_dependencies(app_list):
                if (not model._meta.proxy and model._meta.managed and
                        router.allow_migrate_model(self.connection.alias, model)):
                    queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
                    for obj in queryset.iterator():
                        yield obj
        # Serialize to a string
        out = StringIO()
        serializers.serialize("json", get_objects(), indent=None, stream=out)
        return out.getvalue() 

def create_permissions(app_config, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, apps=global_apps, **kwargs):
    if not app_config.models_module:
        return

    app_label = app_config.label
    try:
        app_config = apps.get_app_config(app_label)
        ContentType = apps.get_model('contenttypes', 'ContentType')
        Permission = apps.get_model('auth', 'Permission')
    except LookupError:
        return

    if not router.allow_migrate_model(using, Permission):
        return

    # This will hold the permissions we're looking for as
    # (content_type, (codename, name))
    searched_perms = []
    # The codenames and ctypes that should exist.
    ctypes = set()
    for klass in app_config.get_models():
        # Force looking up the content types in the current database
        # before creating foreign keys to them.
        ctype = ContentType.objects.db_manager(using).get_for_model(klass)

        ctypes.add(ctype)
        for perm in _get_all_permissions(klass._meta):
            searched_perms.append((ctype, perm))

    # Find all the Permissions that have a content_type for a model we're
    # looking for.  We don't need to check for codenames since we already have
    # a list of the ones we're going to create.
    all_perms = set(Permission.objects.using(using).filter(
        content_type__in=ctypes,
    ).values_list(
        "content_type", "codename"
    ))

    perms = [
        Permission(codename=codename, name=name, content_type=ct)
        for ct, (codename, name) in searched_perms
        if (ct.pk, codename) not in all_perms
    ]
    Permission.objects.using(using).bulk_create(perms)
    if verbosity >= 2:
        for perm in perms:
            print("Adding permission '%s'" % perm) 

def create_permissions(app_config, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, apps=global_apps, **kwargs):
    if not app_config.models_module:
        return

    app_label = app_config.label
    try:
        app_config = apps.get_app_config(app_label)
        ContentType = apps.get_model('contenttypes', 'ContentType')
        Permission = apps.get_model('auth', 'Permission')
    except LookupError:
        return

    if not router.allow_migrate_model(using, Permission):
        return

    # This will hold the permissions we're looking for as
    # (content_type, (codename, name))
    searched_perms = list()
    # The codenames and ctypes that should exist.
    ctypes = set()
    for klass in app_config.get_models():
        # Force looking up the content types in the current database
        # before creating foreign keys to them.
        ctype = ContentType.objects.db_manager(using).get_for_model(klass)

        ctypes.add(ctype)
        for perm in _get_all_permissions(klass._meta):
            searched_perms.append((ctype, perm))

    # Find all the Permissions that have a content_type for a model we're
    # looking for.  We don't need to check for codenames since we already have
    # a list of the ones we're going to create.
    all_perms = set(Permission.objects.using(using).filter(
        content_type__in=ctypes,
    ).values_list(
        "content_type", "codename"
    ))

    perms = [
        Permission(codename=codename, name=name, content_type=ct)
        for ct, (codename, name) in searched_perms
        if (ct.pk, codename) not in all_perms
    ]
    Permission.objects.using(using).bulk_create(perms)
    if verbosity >= 2:
        for perm in perms:
            print("Adding permission '%s'" % perm) 

def create_permissions(app_config, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, apps=global_apps, **kwargs):
    if not app_config.models_module:
        return

    app_label = app_config.label
    try:
        app_config = apps.get_app_config(app_label)
        ContentType = apps.get_model('contenttypes', 'ContentType')
        Permission = apps.get_model('auth', 'Permission')
    except LookupError:
        return

    if not router.allow_migrate_model(using, Permission):
        return

    # This will hold the permissions we're looking for as
    # (content_type, (codename, name))
    searched_perms = []
    # The codenames and ctypes that should exist.
    ctypes = set()
    for klass in app_config.get_models():
        # Force looking up the content types in the current database
        # before creating foreign keys to them.
        ctype = ContentType.objects.db_manager(using).get_for_model(klass)

        ctypes.add(ctype)
        for perm in _get_all_permissions(klass._meta):
            searched_perms.append((ctype, perm))

    # Find all the Permissions that have a content_type for a model we're
    # looking for.  We don't need to check for codenames since we already have
    # a list of the ones we're going to create.
    all_perms = set(Permission.objects.using(using).filter(
        content_type__in=ctypes,
    ).values_list(
        "content_type", "codename"
    ))

    perms = [
        Permission(codename=codename, name=name, content_type=ct)
        for ct, (codename, name) in searched_perms
        if (ct.pk, codename) not in all_perms
    ]
    Permission.objects.using(using).bulk_create(perms)
    if verbosity >= 2:
        for perm in perms:
            print("Adding permission '%s'" % perm) 

def create_permissions(app_config, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, **kwargs):
    if not app_config.models_module:
        return

    try:
        Permission = apps.get_model('auth', 'Permission')
    except LookupError:
        return

    if not router.allow_migrate_model(using, Permission):
        return

    from django.contrib.contenttypes.models import ContentType

    # This will hold the permissions we're looking for as
    # (content_type, (codename, name))
    searched_perms = list()
    # The codenames and ctypes that should exist.
    ctypes = set()
    for klass in app_config.get_models():
        # Force looking up the content types in the current database
        # before creating foreign keys to them.
        ctype = ContentType.objects.db_manager(using).get_for_model(klass)
        ctypes.add(ctype)
        for perm in _get_all_permissions(klass._meta, ctype):
            searched_perms.append((ctype, perm))

    # Find all the Permissions that have a content_type for a model we're
    # looking for.  We don't need to check for codenames since we already have
    # a list of the ones we're going to create.
    all_perms = set(Permission.objects.using(using).filter(
        content_type__in=ctypes,
    ).values_list(
        "content_type", "codename"
    ))

    perms = [
        Permission(codename=codename, name=name, content_type=ct)
        for ct, (codename, name) in searched_perms
        if (ct.pk, codename) not in all_perms
    ]
    # Validate the permissions before bulk_creation to avoid cryptic
    # database error when the verbose_name is longer than 50 characters
    permission_name_max_length = Permission._meta.get_field('name').max_length
    verbose_name_max_length = permission_name_max_length - 11  # len('Can change ') prefix
    for perm in perms:
        if len(perm.name) > permission_name_max_length:
            raise exceptions.ValidationError(
                "The verbose_name of %s.%s is longer than %s characters" % (
                    perm.content_type.app_label,
                    perm.content_type.model,
                    verbose_name_max_length,
                )
            )
    Permission.objects.using(using).bulk_create(perms)
    if verbosity >= 2:
        for perm in perms:
            print("Adding permission '%s'" % perm)