Entity Collection

The ngrx-data library maintains a cache (EntityCache) of entity collections for each entity type in the ngrx store.

An entity_collection implements the EntityCollection<T> interface.

Property	Meaning
ids	Primary key values in default sort order
entities	Map of primary key to entity data values
filter	The user's filtering criteria
loaded	Whether collection was filled by QueryAll; forced false after clear
loading	Whether currently waiting for query results to arrive from the server
changeState	When change-tracking is enabled, the ChangeStates of unsaved entities

You can extend an entity types with additional properties via entity metadata.