EntityCollection - Cesium Documentation

# EntityCollection

#### new EntityCollection()

  An observable collection of `Entity` instances where each entity has a unique id.
  Source: DataSources/EntityCollection.js, line 51

### Members

#### readonlycollectionChanged :Event

  Gets the event that is fired when entities are added or removed from the collection. The generated event is a `EntityCollection.collectionChangedEventCallback`.
  Source: DataSources/EntityCollection.js, line 112

#### readonlyid :String

  Gets a globally unique identifier for this collection.
  Source: DataSources/EntityCollection.js, line 123

#### readonlyvalues :Array.<Entity>

  Gets the array of Entity instances in the collection. This array should not be modified directly.
  Source: DataSources/EntityCollection.js, line 135

### Methods

#### staticEntityCollection.collectionChangedEventCallback(collection, added, removed, changed)

  The signature of the event generated by `EntityCollection#collectionChanged`.

  Name | Type | Description
  --- | --- | ---
  `collection` | EntityCollection | The collection that triggered the event.
  `added` | Array.<Entity> | The array of `Entity` instances that have been added to the collection.
  `removed` | Array.<Entity> | The array of `Entity` instances that have been removed from the collection.
  `changed` | Array.<Entity> | The array of `Entity` instances that have been modified.

  Source: DataSources/EntityCollection.js, line 102

#### add(entity)

  Add an entity to the collection.

  Name | Type | Description
  --- | --- | ---
  `entity` | Entity | The entity to be added.

  ##### Throws:

  - DeveloperError : An entity with already exists in this collection.
  Source: DataSources/EntityCollection.js, line 187

#### computeAvailability() → TimeInterval

  Computes the maximum availability of the entities in the collection. If the collection contains a mix of infinitely available data and non-infinite data, it will return the interval pertaining to the non-infinite data only. If all data is infinite, an infinite interval will be returned.

  ##### Returns:

  The availability of entities in the collection.
  Source: DataSources/EntityCollection.js, line 150

#### contains(entity) → Boolean

  Returns true if the provided entity is in this collection, false otherwise.

  Name | Type | Description
  --- | --- | ---
  `entity` |  | The entity.

  ##### Returns:

  true if the provided entity is in this collection, false otherwise.
  Source: DataSources/EntityCollection.js, line 235

#### getById(id) → Entity

  Gets an entity with the specified id.

  Name | Type | Description
  --- | --- | ---
  `id` | Object | The id of the entity to retrieve.

  ##### Returns:

  The entity with the provided id or undefined if the id did not exist in the collection.
  Source: DataSources/EntityCollection.js, line 307

#### getOrCreateEntity(id) → Entity

  Gets an entity with the specified id or creates it and adds it to the collection if it does not exist.

  Name | Type | Description
  --- | --- | ---
  `id` | Object | The id of the entity to retrieve or create.

  ##### Returns:

  The new or existing object.
  Source: DataSources/EntityCollection.js, line 323

#### remove(entity) → Boolean

  Removes an entity from the collection.

  Name | Type | Description
  --- | --- | ---
  `entity` | Entity | The entity to be removed.

  ##### Returns:

  true if the item was removed, false if it did not exist in the collection.
  Source: DataSources/EntityCollection.js, line 222

#### removeAll()

  Removes all Entities from the collection.
  Source: DataSources/EntityCollection.js, line 275

#### removeById(id) → Boolean

  Removes an entity with the provided id from the collection.

  Name | Type | Description
  --- | --- | ---
  `id` | Object | The id of the entity to remove.

  ##### Returns:

  true if the item was removed, false if no item with the provided id existed in the collection.
  Source: DataSources/EntityCollection.js, line 250

#### resumeEvents()

  Resumes raising `EntityCollection#collectionChanged` events immediately when an item is added or removed. Any modifications made while while events were suspended will be triggered as a single event when this function is called. This function is reference counted and can safely be called multiple times as long as there are corresponding calls to `EntityCollection#resumeEvents`.

  ##### Throws:

  - DeveloperError : resumeEvents can not be called before suspendEvents.
  Source: DataSources/EntityCollection.js, line 82

#### suspendEvents()

  Prevents `EntityCollection#collectionChanged` events from being raised until a corresponding call is made to `EntityCollection#resumeEvents`, at which point a single event will be raised that covers all suspended operations. This allows for many items to be added and removed efficiently. This function can be safely called multiple times as long as there are corresponding calls to `EntityCollection#resumeEvents`.
  Source: DataSources/EntityCollection.js, line 69