django_find.refs module

django_find.refs.child_classes(cls)

Returns all models that have a foreign key pointing to cls.

django_find.refs.get_field_to(cls, target_cls)

django_find.refs.get_join_for(vector)

Given a vector as returned by get_object_vector_for(), this function returns a list of tuples that explain how to join the models (tables) together on the SQL layer. Each tuple has three elements:

(table_name, left_key, right_key)

In the first tuple of the list, left_key is always None. In the second tuple of the list, right_key is always None. All other tuples required both keys to join them.

Complete example (keep in mind that the connection between Component and Unit is many-to-many, so there’s a helper table here):

get_join_path_for((Device, Component, Unit))

This returns:

[
    ('inventory_device', None, None),
    ('inventory_component', 'device_id', 'inventory_device.metadata_id'),
    ('inventory_unit_component', 'component_id', 'inventory_component.id'),
    ('inventory_unit', 'id', 'inventory_unit_component.unit_id')
]

Which means that the following SQL JOIN could be used:

SELECT *
FROM inventory_device
LEFT JOIN inventory_component ON inventory_component.device_id=inventory_device.metadata_id
LEFT JOIN inventory_unit_component ON inventory_unit_component.component_id=inventory_component.id
LEFT JOIN inventory_unit ON inventory_unit.id=inventory_unit_component.unit_id

django_find.refs.get_object_vector_for(cls, search_cls_list, subtype, avoid=None)

Like get_object_vector_to(), but returns a single vector that reaches all of the given classes, if it exists. Only searches classes that are subtype of the given class.

django_find.refs.get_object_vector_to(cls, search_cls, subtype, avoid=None)

Returns a list of all possible paths to the given class. Only searches classes that are subtype of the given class.

django_find.refs.get_subclasses(cls)

Recursively finds all subclasses of the current class. Like Python’s __class__.__subclasses__(), but recursive. Returns a list containing all subclasses.

@type cls: object @param cls: A Python class. @rtype: list(object) @return: A list containing all subclasses.

django_find.refs.parent_classes(cls)

Returns all models that are referenced by a foreign key of the given class.

django_find.refs.sort_vectors_by_primary_cls(vectors, primary_cls)

Sort the vectors by the position of the primary class, and the vector length.

django_find.refs.yield_all_vectors(search_cls_list, subtype)

Yields all possible vectors between all given classes.

django_find.refs.yield_matching_vectors(vectors, search_cls_list)

Yields all possible vectors that connect all of the given classes. The result is sorted by the position of the primary class, and the vector length.