`addRelationshipIdsListener`

The addRelationshipIdsListener method registers a listener function with the Relationships object that will be called whenever a Relationship definition is added or removed.

addRelationshipIdsListener(listener: RelationshipIdsListener): string

	Type	Description
`listener`	`RelationshipIdsListener`	The function that will be called whenever a `Relationship` definition is added or removed.
returns	`string`

The provided listener is a RelationshipIdsListener function, and will be called with a reference to the Relationships object.

Example

This example creates a Store, a Relationships object, and then registers a listener that responds to the addition and the removal of a Relationship definition.

const store = createStore()
  .setTable('pets', {
    fido: {species: 'dog'},
    felix: {species: 'cat'},
    cujo: {species: 'dog'},
  })
  .setTable('species', {
    wolf: {price: 10},
    dog: {price: 5},
    cat: {price: 4},
  });

const relationships = createRelationships(store);
const listenerId = relationships.addRelationshipIdsListener(
  (relationships) => {
    console.log(relationships.getRelationshipIds());
  },
);

relationships.setRelationshipDefinition(
  'petSpecies',
  'pets',
  'species',
  'species',
);
// -> ['petSpecies']
relationships.delRelationshipDefinition('petSpecies');
// -> []

relationships.delListener(listenerId);

Since

v4.1.0