| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
A "wrapper" for IList implementations that handles ItemPendingErrors
thrown by
getItemAt().
The getItemAt() method handles ItemPendingErrors by returning a provisional
"pending" item until the underlying request succeeds or fails. The provisional
item is produced by calling createPendingItemFunction. If the request
succeeds, the actual item replaces the provisional one, and if it fails
the provisional item is replaced by with the item returned by calling
createFailedItemFunction.
This class delegates the IList methods and properties to its list.
If a list isn't specified, methods that mutate the collection are no-ops,
and methods that query the collection return an "empty" value like null or zero
as appropriate.
This class is intended to be used with Spark components based on DataGroup,
like List and ComboBox, which don't provide intrinsic support for
ItemPendingError handling.
createFailedItemFunction:Function
A function that's used to create a substitute item when
a request which had caused an ItemPendingError to be thrown,
subsequently fails. The existing item, typically a pending item created
with the value of createPendingItemFunction(), is replaced
with the failed item.
The value of this property must be a function with two parameters, the index
of the requested item, and the failure "info" object, which is
passed along from the IResponder fault() method. In most cases second parameter
can be ignored, e.g.:
function createFailedItem(index:int, info:Object):Object
{
return "[" + index + "request failed]";
}
Setting this property does not affect failed items that were already
created. Setting this property to null will prevent failed items from being created.
The default value is A function that unconditionally returns null..
Implementation public function get createFailedItemFunction():Function public function set createFailedItemFunction(value:Function):voidSee also
createPendingItemFunction:Function
A function that's used to create a provisional item when
the initial request causes an ItemPendingError to be thrown.
If the request eventually succeeds, the provisional item is automatically
replaced by the actual item. If the request fails, then the item is replaced
with one created with the createFailedItemFunction.
The value of this property must be a function with two parameters, the index
of the requested dataProvider item, and the ItemPendingError itself. In most
cases second parameter can be ignored, e.g.:
function createPendingItem(index:int, ipe:ItemPendingError):Object
{
return "[" + index + "request is pending...]";
}
Setting this property does not affect provisional pending items that were already
created. Setting this property to null will prevent provisional pending items
from being created.
The default value is A function that unconditionally returns null..
Implementation public function get createPendingItemFunction():Function public function set createPendingItemFunction(value:Function):voidSee also
length:int [read-only]
| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
The number of items in this collection.
0 means no items while -1 means the length is unknown.
This property can be used as the source for data binding. When this property is modified, it dispatches the propertyChange event.
Implementation public function get length():intlist:IList| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
The IList that this collection view "wraps", i.e. the object to which all of
the IList metods are delegated.
If this property is null, the IList mutation methods, like setItemAt(),
are no-ops and the IList query methods, like getItemAt() return, null
or zero (-1 for getItemIndex()), as appropriate.
The default value is null.
This property can be used as the source for data binding. When this property is modified, it dispatches the propertyChange event.
Implementation public function get list():IList public function set list(value:IList):voidpublic function AsyncListView(list:IList = null)| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
AsyncListView constructor.
Parameters | list:IList (default = null) |
public function addItem(item:Object):void| Language Version: | ActionScript 3.0 |
| 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.
|
public function addItemAt(item:Object, index:int):void| Language Version: | ActionScript 3.0 |
| 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.
|
public function getItemAt(index:int, prefetch:int = 0):Object| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Returns the value of list.getItemAt(index).
This method catches ItemPendingErrors (IPEs) generated as a consequence of
calling getItemAt(). If an IPE is thrown, an IResponder is added to
the IPE and a provisional "pending" item, created with the
createPendingItemFunction is returned. If the underlying request
eventually succeeds, the pending item is replaced with the real item. If it fails,
the pending item is replaced with a value produced by calling
createFailedItemFunction.
Parameters
| index:int — The list index from which to retrieve the item.
|
| |
| prefetch:int (default = 0)int indicating both the direction
and number of items to fetch during the request if the item is not local.
|
Returns | Object — The list item at the specified index.
|
ThrowsSee also
public function getItemIndex(item:Object):int| Language Version: | ActionScript 3.0 |
| 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.
|
public function itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Notifies the view that an item has been updated.
This is useful if the contents of the view do not implement
IEventDispatcher and dispatches a
PropertyChangeEvent.
If a property is specified 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) |
| |
| oldValue:Object (default = null) |
| |
| newValue:Object (default = null) |
public function removeAll():void| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Removes all items from the list.
If any item is not local and an asynchronous operation must be
performed, an ItemPendingError will be thrown.
See the ItemPendingError documentation as well as
the collections documentation for more information
on using the ItemPendingError.
public function removeItemAt(index:int):Object| Language Version: | ActionScript 3.0 |
| 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.
|
public function setItemAt(item:Object, index:int):Object| Language Version: | ActionScript 3.0 |
| 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.
|
public function toArray():Array| Language Version: | ActionScript 3.0 |
| 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 public function toString():String| Language Version: | ActionScript 3.0 |
| 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.
|
Event Object Type: mx.events.CollectionEventproperty CollectionEvent.type = mx.events.CollectionEvent.COLLECTION_CHANGE| Language Version: | ActionScript 3.0 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Dispatched when the list's length has changed or when a list
element is replaced.
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 |
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Sat Oct 3 2009, 04:15 AM -07:00 
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