class ModelSchema(models.Model):
name = models.CharField(max_length=32, unique=True)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._registry = ModelRegistry(self.app_label)
self._initial_name = self.name
initial_model = self.get_registered_model()
self._schema_editor = ModelSchemaEditor(initial_model)
def save(self, **kwargs):
super().save(**kwargs)
cache.update_last_modified(self.model_name)
cache.update_last_modified(self.initial_model_name)
self._schema_editor.update_table(self._factory.make_model())
self._initial_name = self.name
def delete(self, **kwargs):
self._schema_editor.drop_table(self.as_model())
self._factory.destroy_model()
cache.clear_last_modified(self.initial_model_name)
super().delete(**kwargs)
def get_registered_model(self):
return self._registry.get_model(self.model_name)
@property
def _factory(self):
return ModelFactory(self)
@property
def app_label(self):
return config.dynamic_models_app_label()
@property
def model_name(self):
return self.get_model_name(self.name)
@property
def initial_model_name(self):
return self.get_model_name(self._initial_name)
@classmethod
def get_model_name(cls, name):
return name.title().replace(" ", "")
@property
def db_table(self):
parts = (self.app_label, slugify(self.name).replace("-", "_"))
return "_".join(parts)
def as_model(self):
return self._factory.get_model()
def test_update_table_alters_if_table_exists(self, initial_model,
changed_model):
assert db_table_exists("tests_initialmodel")
assert not db_table_exists("tests_changedmodel")
ModelSchemaEditor(initial_model).update_table(changed_model)
assert db_table_exists("tests_changedmodel")
assert not db_table_exists("tests_initialmodel")
def initial_field_table(self, initial_model):
ModelSchemaEditor().create_table(initial_model)
def bare_table(self, bare_model):
ModelSchemaEditor().create_table(bare_model)
def test_drop_table(self, initial_model):
assert db_table_exists("tests_initialmodel")
ModelSchemaEditor().drop_table(initial_model)
assert not db_table_exists("tests_initialmodel")
def test_update_table_creates_if_not_exists(self, initial_model):
assert not db_table_exists("tests_initialmodel")
ModelSchemaEditor().update_table(initial_model)
assert db_table_exists("tests_initialmodel")
def test_alter_table(self, initial_model, changed_model):
assert db_table_exists('tests_initialmodel')
assert not db_table_exists('tests_changedmodel')
ModelSchemaEditor(initial_model).alter_table(changed_model)
assert db_table_exists('tests_changedmodel')
assert not db_table_exists('tests_initialmodel')
def test_create_table(self, initial_model):
assert not db_table_exists('tests_initialmodel')
ModelSchemaEditor().create_table(initial_model)
assert db_table_exists('tests_initialmodel')
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._registry = ModelRegistry(self.app_label)
self._initial_name = self.name
initial_model = self.get_registered_model()
self._schema_editor = ModelSchemaEditor(initial_model)
class ModelSchema(models.Model):
name = models.CharField(max_length=32, unique=True)
_modified = models.DateTimeField(auto_now=True)
_cache = LastModifiedCache()
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._registry = ModelRegistry(self.app_label)
self._initial_name = self.name
initial_model = self.get_registered_model()
self._schema_editor = ModelSchemaEditor(initial_model)
def save(self, **kwargs):
super().save(**kwargs)
self.last_modified = self._modified
self._schema_editor.update_table(self._factory.make_model())
def delete(self, **kwargs):
self._schema_editor.drop_table(self.as_model())
self._factory.destroy_model()
del self.last_modified
super().delete(**kwargs)
@property
def last_modified(self):
return self._cache.get(self)
@last_modified.setter
def last_modified(self, timestamp):
self._cache.set(self, timestamp)
@last_modified.deleter
def last_modified(self):
self._cache.delete(self)
def get_registered_model(self):
return self._registry.get_model(self.model_name)
def is_current_schema(self):
return self._modified >= self.last_modified
def is_current_model(self, model):
if model._schema.pk != self.pk:
raise ValueError("Can only be called on a model of this schema")
return model._declared >= self.last_modified
@property
def _factory(self):
return ModelFactory(self)
@property
def app_label(self):
return config.dynamic_models_app_label()
@property
def model_name(self):
return self.get_model_name(self.name)
@property
def initial_model_name(self):
return self.get_model_name(self._initial_name)
@classmethod
def get_model_name(cls, name):
return name.title().replace(' ', '')
@property
def db_table(self):
parts = (self.app_label, slugify(self.name).replace('-', '_'))
return '_'.join(parts)
def as_model(self):
return self._factory.get_model()
def test_model_is_changed(self, initial_model, changed_model):
assert ModelSchemaEditor(initial_model).has_changed(changed_model)
def test_model_is_not_changed(self, initial_model):
assert not ModelSchemaEditor(initial_model).has_changed(initial_model)