ormar/docs/api/models/helpers/models.md

models.helpers.models

is_field_an_forward_ref

is_field_an_forward_ref(field: Type["BaseField"]) -> bool

Checks if field is a relation field and whether any of the referenced models are ForwardRefs that needs to be updated before proceeding.

Arguments:

• field (Type[BaseField]): model field to verify

Returns:

(bool): result of the check

populate_default_options_values

populate_default_options_values(new_model: Type["Model"], model_fields: Dict) -> None

Sets all optional Meta values to it's defaults and set model_fields that were already previously extracted.

Here should live all options that are not overwritten/set for all models.

Current options are:

• constraints = []
• abstract = False

Arguments:

• new_model (Model class): newly constructed Model
• model_fields (Union[Dict[str, type], Dict]): dict of model fields

substitue_backend_pool_for_sqlite

substitue_backend_pool_for_sqlite(new_model: Type["Model"]) -> None

Recreates Connection pool for sqlite3 with new factory that executes "PRAGMA foreign_keys=1; on initialization to enable foreign keys.

Arguments:

• new_model (Model class): newly declared ormar Model

check_required_meta_parameters

check_required_meta_parameters(new_model: Type["Model"]) -> None

Verifies if ormar.Model has database and metadata set.

Recreates Connection pool for sqlite3

Arguments:

• new_model (Model class): newly declared ormar Model

extract_annotations_and_default_vals

extract_annotations_and_default_vals(attrs: Dict) -> Tuple[Dict, Dict]

Extracts annotations from class namespace dict and triggers extraction of ormar model_fields.

Arguments:

• attrs (Dict): namespace of the class created

Returns:

(Tuple[Dict, Dict]): namespace of the class updated, dict of extracted model_fields

validate_related_names_in_relations

validate_related_names_in_relations(model_fields: Dict, new_model: Type["Model"]) -> None

Performs a validation of relation_names in relation fields. If multiple fields are leading to the same related model only one can have empty related_name param (populated by default as model.name.lower()+'s'). Also related_names have to be unique for given related model.

Raises:

• ModelDefinitionError: if validation of related_names fail

Arguments:

• model_fields (Dict[str, ormar.Field]): dictionary of declared ormar model fields
• new_model (Model class):

group_related_list

group_related_list(list_: List) -> Dict

Translates the list of related strings into a dictionary. That way nested models are grouped to traverse them in a right order and to avoid repetition.

Sample: ["people__houses", "people__cars__models", "people__cars__colors"] will become: {'people': {'houses': [], 'cars': ['models', 'colors']}}

Result dictionary is sorted by length of the values and by key

Arguments:

• list_ (List[str]): list of related models used in select related

Returns:

(Dict[str, List]): list converted to dictionary to avoid repetition and group nested models