Class: Collection

Extends

• ol.Object

Observable Properties

Name	Type	Settable	ol.ObjectEvent type	Description
length	number	no	change:length	The length of the array.

Methods

bindTo(key, target, opt_targetKey){ol.ObjectAccessor} inherited experimental

src/ol/object.js, line 301

The bindTo method allows you to set up a two-way binding between a source and target object. The method returns an object with a transform method that you can use to provide from and to functions to transform values on the way from the source to the target and on the way back.

For example, if you had two map views (sourceView and targetView) and you wanted the target view to have double the resolution of the source view, you could transform the resolution on the way to and from the target with the following:

sourceView.bindTo('resolution', targetView)
  .transform(
    function(sourceResolution) {
      // from sourceView.resolution to targetView.resolution
      return 2 * sourceResolution;
    },
    function(targetResolution) {
      // from targetView.resolution to sourceView.resolution
      return targetResolution / 2;
    }
  );

Name	Type	Description
key	string	Key name.
target	ol.Object	Target.
targetKey	string	Target key.

clear()

src/ol/collection.js, line 110

Remove all elements from the collection.

dispatchChangeEvent() inherited experimental

src/ol/observable.js, line 42

Dispatches a change event.

Fires:

• change experimental

extend(arr){ol.Collection.<T>}

src/ol/collection.js, line 122

Name	Type	Description
arr	Array.<T>	Array.

Returns:

This collection.

forEach(f, opt_this)

src/ol/collection.js, line 140

Iterate over each element, calling the provided callback.

Name	Type	Description
f	function	The function to call for every element. This function takes 3 arguments (the element, the index and the array). The return value is ignored.
this	S	The object to use as this in f.

get(key){*} inherited experimental

src/ol/object.js, line 358

Gets a value.

Name	Type	Description
key	string	Key name.

Returns:

Value.

getArray(){Array.<T>}

src/ol/collection.js, line 153

Get a reference to the underlying Array object. Warning: if the array is mutated, no events will be dispatched by the collection, and the collection's "length" property won't be in sync with the actual length of the array.

Returns:

Array.

getKeys(){Array.<string>} inherited experimental

src/ol/object.js, line 386

Get a list of object property names.

Returns:

List of property names.

getLength(){number}

src/ol/collection.js, line 175

Get the length of this collection.

Returns:

The length of the array.

getProperties(){Object.<string, *>} inherited experimental

src/ol/object.js, line 418

Get an object of all property names and values.

Returns:

Object.

getRevision(){number} inherited experimental

src/ol/observable.js, line 52

Returns:

Revision.

insertAt(index, elem)

src/ol/collection.js, line 186

Insert an element at the provided index.

Name	Type	Description
index	number	Index.
elem	T	Element.

item(index){T}

src/ol/collection.js, line 164

Get the element at the provided index.

Name	Type	Description
index	number	Index.

Returns:

Element.

on(type, listener, opt_this){goog.events.Key} inherited

src/ol/observable.js, line 65

Listen for a certain type of event.

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object to use as this in listener.

Returns:

Unique key for the listener.

once(type, listener, opt_this){goog.events.Key} inherited

src/ol/observable.js, line 78

Listen once for a certain type of event.

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object to use as this in listener.

Returns:

Unique key for the listener.

pop(){T|undefined}

src/ol/collection.js, line 200

Remove the last element of the collection and return it. Return undefined if the collection is empty.

Returns:

Element.

push(elem){number}

src/ol/collection.js, line 211

Insert the provided element at the end of the collection.

Name	Type	Description
elem	T	Element.

Returns:

Length.

remove(elem){T|undefined}

src/ol/collection.js, line 224

Removes the first occurence of elem from the collection.

Name	Type	Description
elem	T	Element.

Returns:

The removed element or undefined if elem was not found.

removeAt(index){T|undefined}

src/ol/collection.js, line 243

Remove the element at the provided index and return it. Return undefined if the collection does not contain this index.

Name	Type	Description
index	number	Index.

Returns:

Value.

set(key, value) inherited experimental

src/ol/object.js, line 448

Sets a value.

Name	Type	Description
key	string	Key name.
value	*	Value.

setAt(index, elem)

src/ol/collection.js, line 259

Set the element at the provided index.

Name	Type	Description
index	number	Index.
elem	T	Element.

setProperties(values) inherited experimental

src/ol/object.js, line 477

Sets a collection of key-value pairs.

Name	Type	Description
values	Object.<string, *>	Values.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 91

Unlisten for a certain type of event.

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object which was used as this by the listener.

unbind(key) inherited experimental

src/ol/object.js, line 491

Removes a binding. Unbinding will set the unbound property to the current value. The object will not be notified, as the value has not changed.

Name	Type	Description
key	string	Key name.

unbindAll() inherited experimental

src/ol/object.js, line 515

Removes all bindings.

unByKey(key) inherited

src/ol/observable.js, line 101

Removes an event listener using the key returned by on() or once().

Name	Type	Description
key	goog.events.Key	Key.