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ListCollectionView

Package | mx.collections
Class | public class ListCollectionView
Inheritance | ListCollectionView flash.utils.Proxy
Implements | ICollectionView, IList, IMXMLObject
Subclasses | ArrayCollection, VectorCollection, XMLListCollection

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

The ListCollectionView class adds the properties and methods of the `ICollectionView` interface to an object that conforms to the `IList` interface. As a result, you can pass an object of this class to anything that requires an `IList` or `ICollectionView`.

This class also lets you use [ ] array notation to access the `getItemAt()` and `setItemAt()` methods. If you use code such as `myListCollectionView[index]` Flex calls the `myListCollectionView` object's `getItemAt()` or `setItemAt()` method.

MXML Syntax Show MXML Syntax
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The `<mx:ListCollectionView>` has the following attributes, which all of its subclasses inherit:

      <mx:ListCollectionView
      Properties
      filterFunction="null"
      list="null"
      sort="null"
      Events
      collectionChange="No default"
      />

Public Properties

| Property | Defined By
--- | --- | ---
|  | complexFieldWatcher : ComplexFieldChangeWatcher | ListCollectionView
|  | filterFunction : Function A function that the view will use to eliminate items that do not match the function's criteria. | ListCollectionView
|  | length : int [read-only] The number of items in this view. | ListCollectionView
|  | list : IList The IList that this collection view wraps. | ListCollectionView
|  | sort : ISort The ISort that will be applied to the ICollectionView. | ListCollectionView

Protected Properties

| Property | Defined By
--- | --- | ---
|  | localIndex : Array When the view is sorted or filtered the localIndex property contains an array of items in the sorted or filtered (ordered, reduced) view, in the sorted order. | ListCollectionView

Public Methods

| Method | Defined By
--- | --- | ---
|  | ListCollectionView(list:IList = null) The ListCollectionView constructor. | ListCollectionView
|  | addAll(addList:IList):void Adds a list of items to the current list, placing them at the end of the list in the order they are passed. | ListCollectionView
|  | addAllAt(addList:IList, index:int):void Adds a list of items to the current list, placing them at the position index passed in to the function. | ListCollectionView
|  | addEventListener(eventType:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void | ListCollectionView
|  | addItem(item:Object):void Adds the specified item to the end of the list. | ListCollectionView
|  | addItemAt(item:Object, index:int):void Adds the item at the specified index. | ListCollectionView
|  | contains(item:Object):Boolean Returns whether the view contains the specified object. | ListCollectionView
|  | createCursor():IViewCursor Creates a new IViewCursor that works with this view. | ListCollectionView
|  | disableAutoUpdate():void Prevents changes to the collection itself and items within the collection from being dispatched by the view. | ListCollectionView
|  | dispatchEvent(event:Event):Boolean | ListCollectionView
|  | enableAutoUpdate():void Enables auto-updating. | ListCollectionView
|  | getItemAt(index:int, prefetch:int = 0):Object Gets the item at the specified index. | ListCollectionView
|  | getItemIndex(item:Object):int Returns the index of the item if it is in the list such that getItemAt(index) == item. | ListCollectionView
|  | hasEventListener(eventType:String):Boolean | ListCollectionView
|  | initialized(document:Object, id:String):void Called automatically by the MXML compiler when the ListCollectionView is created using an MXML tag. | ListCollectionView
|  | itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void Notifies the view that an item has been updated. | ListCollectionView
|  | refresh():Boolean Applies the sort and filter to the view. | ListCollectionView
|  | removeAll():void Remove all items from the list. | ListCollectionView
|  | removeEventListener(eventType:String, listener:Function, useCapture:Boolean = false):void | ListCollectionView
|  | removeItem(item:Object):Boolean Removes the specified item from this list, should it exist. | ListCollectionView
|  | removeItemAt(index:int):Object Removes the item at the specified index and returns it. | ListCollectionView
|  | setItemAt(item:Object, index:int):Object Places the item at the specified index. | ListCollectionView
|  | toArray():Array Returns an Array that is populated in the same order as the IList implementation. | ListCollectionView
|  | toString():String Prints the contents of this view to a string and returns it. | ListCollectionView
|  | willTrigger(eventType:String):Boolean | ListCollectionView

Events

| Event | Summary | Defined By
--- | --- | --- | ---
|  | collectionChange | Dispatched when the ICollectionView has been updated in some way. | ListCollectionView

Property Detail

complexFieldWatcher | property

`complexFieldWatcher:ComplexFieldChangeWatcher`

Implementation
`public function get complexFieldWatcher():ComplexFieldChangeWatcher`
`public function set complexFieldWatcher(value:ComplexFieldChangeWatcher):void`

filterFunction | property |

`filterFunction:Function`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

A function that the view will use to eliminate items that do not match the function's criteria. A filterFunction is expected to have the following signature:

    f(item:Object):Boolean

where the return value is `true` if the specified item should remain in the view.

If a filter is unsupported, Flex throws an error when accessing this property. You must call `refresh()` after setting the `filterFunction` property for the view to update.

Note: The Flex implementations of ICollectionView retrieve all items from a remote location before executing the filter function. If you use paging, apply the filter to the remote collection before you retrieve the data.

This property can be used as the source for data binding.

Implementation
`public function get filterFunction():Function`
`public function set filterFunction(value:Function):void`

See also

refresh()

length | property |

`length:int` [read-only]

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

The number of items in this view. 0 means no items, while -1 means that the length is unknown.

This property can be used as the source for data binding.

Implementation
`public function get length():int`

list | property |

`list:IList`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

The IList that this collection view wraps.

This property can be used as the source for data binding.

Implementation
`public function get list():IList`
`public function set list(value:IList):void`

localIndex | property |

`protected var localIndex:Array`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

When the view is sorted or filtered the `localIndex` property contains an array of items in the sorted or filtered (ordered, reduced) view, in the sorted order. The ListCollectionView class uses this property to access the items in the view. The `localIndex` property should never contain anything that is not in the source, but may not have everything in the source. This property is `null` when there is no sort.

sort | property |

`sort:ISort`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

The ISort that will be applied to the ICollectionView. Setting the sort does not automatically refresh the view, so you must call the `refresh()` method after setting this property. If sort is unsupported an error will be thrown when accessing this property.

Note: The Flex implementations of ICollectionView retrieve all items from a remote location before executing a sort. If you use paging with a sorted list, apply the sort to the remote collection before you retrieve the data.

This property can be used as the source for data binding.

Implementation
`public function get sort():ISort`
`public function set sort(value:ISort):void`

See also

refresh()
Constructor Detail

ListCollectionView | () | Constructor

`public function ListCollectionView(list:IList = null)`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

The ListCollectionView constructor.

Parameters

| `list:IList` (default = `null`)`` — the IList this ListCollectionView is meant to wrap.

Method Detail

addAll | () | method

`public function addAll(addList:IList):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Adds a list of items to the current list, placing them at the end of the list in the order they are passed.

Parameters

| `addList:IList` — IList The list of items to add to the current list

addAllAt | () | method |

`public function addAllAt(addList:IList, index:int):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Adds a list of items to the current list, placing them at the position index passed in to the function. The items are placed at the index location and placed in the order they are recieved.

Parameters

| `addList:IList` — IList The list of items to add to the current list
| `index:int` — The location of the current list to place the new items.

Throws

| `RangeError` — if index is less than 0 or greater than the length of the list.

addEventListener | () | method |

`public function addEventListener(eventType:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Parameters

| `eventType:String`
| `listener:Function`
| `useCapture:Boolean` (default = `false`)``
| `priority:int` (default = `0`)``
| `useWeakReference:Boolean` (default = `false`)``

addItem | () | method |

`public function addItem(item:Object):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Adds the specified item to the end of the list. Equivalent to `addItemAt(item, length)`.

Parameters

| `item:Object` — The item to add.

addItemAt | () | method |

`public function addItemAt(item:Object, index:int):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Adds the item at the specified index. The index of any item greater than the index of the added item is increased by one. If the the specified index is less than zero or greater than the length of the list, a RangeError is thrown.

Parameters

| `item:Object` — The item to place at the index.
| `index:int` — The index at which to place the item.

contains | () | method |

`public function contains(item:Object):Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Returns whether the view contains the specified object. Unlike the `IViewCursor.findxxx` methods, this search is succesful only if it finds an item that exactly matches the parameter. If the view has a filter applied to it this method may return `false` even if the underlying collection does contain the item.

Parameters

| `item:Object` — The object to look for.

Returns

| `Boolean` — true if the ICollectionView, after applying any filter, contains the item; false otherwise.

See also

enableAutoUpdate()
mx.events.CollectionEvent

createCursor | () | method |

`public function createCursor():IViewCursor`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Creates a new IViewCursor that works with this view.

Returns

| `IViewCursor` — A new IViewCursor implementation.

disableAutoUpdate | () | method |

`public function disableAutoUpdate():void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Prevents changes to the collection itself and items within the collection from being dispatched by the view. Also prevents the view from updating the positions of items if the positions change in the collection. The changes will be queued and dispatched appropriately after `enableAutoUpdate` is called. If more events than updates to a single item occur, the view may end up resetting. The `disableAutoUpdate` method acts cumulatively; the same number of calls to `enableAutoUpdate` are required for the view to dispatch events and refresh. Note that `disableAutoUpdate` only affects the individual view; edits may be detected on an individual basis by other views.

See also

mx.collections.ICollectionView.enableAutoUpdate()
mx.events.CollectionEvent

dispatchEvent | () | method |

`public function dispatchEvent(event:Event):Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Parameters

| `event:Event`

Returns

| `Boolean`

enableAutoUpdate | () | method |

`public function enableAutoUpdate():void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Enables auto-updating. See `disableAutoUpdate` for more information.

See also

mx.collections.ICollectionView.disableAutoUpdate()

getItemAt | () | method |

`public function getItemAt(index:int, prefetch:int = 0):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Gets the item at the specified index.

Parameters

| `index:int` — The index in the list from which to retrieve the item.
| `prefetch:int` (default = `0`)`` — An `int` indicating both the direction and number of items to fetch during the request if the item is not local.

Returns

| `Object` — The item at that index, or `null` if there is none.

getItemIndex | () | method |

`public function getItemIndex(item:Object):int`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Returns the index of the item if it is in the list such that getItemAt(index) == item.

Note: unlike `IViewCursor.findxxx()` methods, The `getItemIndex()` method cannot take a parameter with only a subset of the fields in the item being serched for; this method always searches for an item that exactly matches the input parameter.

Parameters

| `item:Object` — The item to find.

Returns

| `int` — The index of the item, or -1 if the item is not in the list.

hasEventListener | () | method |

`public function hasEventListener(eventType:String):Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Parameters

| `eventType:String`

Returns

| `Boolean`

initialized | () | method |

`public function initialized(document:Object, id:String):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Called automatically by the MXML compiler when the ListCollectionView is created using an MXML tag. If you create the ListCollectionView through ActionScript, you must call this method passing in the MXML document and `null` for the `id`.

Parameters

| `document:Object` — The MXML document containing this ListCollectionView.
| `id:String` — Ignored.

itemUpdated | () | method |

`public function itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Notifies the view that an item has been updated. This method is useful if the contents of the view do not implement `IPropertyChangeNotifier`. If the call to this method includes a `property` parameter, the view may be able to optimize its notification mechanism. Otherwise it may choose to simply refresh the whole view.

Parameters

| `item:Object` — The item within the view that was updated.
| `property:Object` (default = `null`)`` — The name of the property that was updated.
| `oldValue:Object` (default = `null`)`` — The old value of that property. (If property was null, this can be the old value of the item.).
| `newValue:Object` (default = `null`)`` — The new value of that property. (If property was null, there's no need to specify this as the item is assumed to be the new value.)

See also

mx.events.CollectionEvent
mx.core.IPropertyChangeNotifier
mx.events.PropertyChangeEvent

refresh | () | method |

`public function refresh():Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Applies the sort and filter to the view. The ICollectionView does not detect changes to a sort or filter automatically, so you must call the `refresh()` method to update the view after setting the `sort` or `filterFunction` property. If your ICollectionView implementation also implements the IMXMLObject interface, you should to call the `refresh()` method from your `initialized()` method.

Returns `true` if the refresh was successful and `false` if the sort is not yet complete (e.g., items are still pending). A client of the view should wait for a CollectionEvent event with the `CollectionEventKind.REFRESH` `kind` property to ensure that the `refresh()` operation is complete.

Returns

| `Boolean` — `true` if the refresh() was complete, `false` if the refresh() is incomplete.

removeAll | () | method |

`public function removeAll():void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Remove all items from the list.

removeEventListener | () | method |

`public function removeEventListener(eventType:String, listener:Function, useCapture:Boolean = false):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Parameters

| `eventType:String`
| `listener:Function`
| `useCapture:Boolean` (default = `false`)``

removeItem | () | method |

`public function removeItem(item:Object):Boolean`

Language Version : | ActionScript 3.0

Product Version : | Apache Flex

Runtime Versions : | Flash Player 9, AIR 1.1

Removes the specified item from this list, should it exist. Relies on ArrayList implementation

Parameters

| `item:Object` — Object reference to the item that should be removed.

Returns

| `Boolean` — Boolean indicating if the item was removed.

removeItemAt | () | method |

`public function removeItemAt(index:int):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Removes the item at the specified index and returns it. Any items that were after this index are now one index earlier.

Parameters

| `index:int` — The index from which to remove the item.

Returns

| `Object` — The item that was removed.

setItemAt | () | method |

`public function setItemAt(item:Object, index:int):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Places the item at the specified index. If an item was already at that index the new item will replace it and it will be returned.

Parameters

| `item:Object` — The new item to be placed at the specified index.
| `index:int` — The index at which to place the item.

Returns

| `Object` — The item that was replaced, or `null` if none.

toArray | () | method |

`public function toArray():Array`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Returns an Array that is populated in the same order as the IList implementation. This method can throw an ItemPendingError.

Returns

| `Array` — The array.

toString | () | method |

`public function toString():String`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Prints the contents of this view to a string and returns it.

Returns

| `String` — The contents of this view, in string form.

willTrigger | () | method |

`public function willTrigger(eventType:String):Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Parameters

| `eventType:String`

Returns

| `Boolean`

Event Detail

collectionChange | Event

Event Object Type: `mx.events.CollectionEvent`
CollectionEvent.type property = `mx.events.CollectionEvent.COLLECTION_CHANGE`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

Dispatched when the ICollectionView has been updated in some way.

The CollectionEvent.COLLECTION_CHANGE constant defines the value of the `type` property of the event object for an event that is dispatched when a collection has changed.

The properties of the event object have the following values. Not all properties are meaningful for all kinds of events. See the detailed property descriptions for more information.

Property | Value
--- | ---
`bubbles` | false
`cancelable` | false
`currentTarget` | The Object that defines the event listener that handles the event. For example, if you use `myButton.addEventListener()` to register an event listener, myButton is the value of the `currentTarget`.
`items` | An Array of objects with information about the items affected by the event. The contents of this field depend on the event kind; for details see the `items` property
`kind` | The kind of event. The valid values are defined in the CollectionEventKind class as constants.
`location` | Location within the target collection of the item(s) specified in the `items` property.
`oldLocation` | the previous location in the collection of the item specified in the `items` property.
`target` | The Object that dispatched the event; it is not always the Object listening for the event. Use the `currentTarget` property to always access the Object listening for the event.
`type` | CollectionEvent.COLLECTION_CHANGE

Wed Nov 15 2017, 09:50 AM +01:00