Adobe® Flex® 4 Language Reference
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mx.collections 
HierarchicalCollectionView 
Packagemx.collections
Classpublic class HierarchicalCollectionView
InheritanceHierarchicalCollectionView Inheritance EventDispatcher Inheritance Object
Implements IHierarchicalCollectionView, IXMLNotifiable

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The HierarchicalCollectionView class provides a hierarchical view of a standard collection.

MXML SyntaxexpandedHide MXML Syntax
The <mx.HierarchicalCollectionView> inherits all the tag attributes of its superclass, and defines the following tag attributes:

  <mx:HierarchicalCollectionView
  Properties 
    showRoot="true|false"
    source="No default"
  />
  


Public Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  hasRoot : Boolean
[read-only] A flag that, if true, indicates that the current data provider has a root node; for example, a single top-level node in a hierarchical structure.
HierarchicalCollectionView
  length : int
[read-only] The length of the currently parsed collection.
HierarchicalCollectionView
  openNodes : Object
An Array of Objects containing the data provider element for all the open branch nodes of the data.
HierarchicalCollectionView
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  showRoot : Boolean
A Boolean flag that specifies whether to display the data provider's root node.
HierarchicalCollectionView
  source : IHierarchicalData
The source data of the IHierarchicalCollectionView.
HierarchicalCollectionView
Public Methods
 MethodDefined By
  
HierarchicalCollectionView(hierarchicalData:IHierarchicalData = null, argOpenNodes:Object = null)
Constructor.
HierarchicalCollectionView
  
addChild(parent:Object, newChild:Object):Boolean
Adds a child node to a node of the data.
HierarchicalCollectionView
  
addChildAt(parent:Object, newChild:Object, index:int):Boolean
Add a child node to a node at the specified index.
HierarchicalCollectionView
 Inherited
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.
EventDispatcher
  
Closes a node to hide its children.
HierarchicalCollectionView
  
Checks the collection for the data item using standard equality test.
HierarchicalCollectionView
  
Returns a new instance of a view iterator over the items in this view.
HierarchicalCollectionView
 Inherited
Dispatches an event into the event flow.
EventDispatcher
  
Returns a collection of children, if they exist.
HierarchicalCollectionView
  
Returns the depth of the node in the collection.
HierarchicalCollectionView
  
Returns the parent of a node.
HierarchicalCollectionView
 Inherited
Checks whether the EventDispatcher object has any listeners registered for a specific type of event.
EventDispatcher
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
  
Opens a node to display its children.
HierarchicalCollectionView
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
  
Applies the sort and filter to the view.
HierarchicalCollectionView
  
Removes the child node from the parent node.
HierarchicalCollectionView
  
Removes the child node from a node at the specified index.
HierarchicalCollectionView
 Inherited
removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void
Removes a listener from the EventDispatcher object.
EventDispatcher
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
 Inherited
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
EventDispatcher
  
xmlNotification(currentTarget:Object, type:String, target:Object, value:Object, detail:Object):void
Called whenever an XML object contained in our list is updated in some way.
HierarchicalCollectionView
Events
 Event Summary Defined By
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.EventDispatcher
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.EventDispatcher
Property Detail

hasRoot

property
hasRoot:Boolean  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

A flag that, if true, indicates that the current data provider has a root node; for example, a single top-level node in a hierarchical structure. XML and Object are examples of data types that have a root node, while Lists and Arrays do not.



Implementation
    public function get hasRoot():Boolean

length

property 
length:int  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The length of the currently parsed collection.



Implementation
    public function get length():int

openNodes

property 
openNodes:Object

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

An Array of Objects containing the data provider element for all the open branch nodes of the data.



Implementation
    public function get openNodes():Object
    public function set openNodes(value:Object):void

showRoot

property 
showRoot:Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

A Boolean flag that specifies whether to display the data provider's root node. If the source data has a root node, and this property is set to false, the collection will not include the root item. Only the descendants of the root item will be included in the collection.

This property has no effect on a source with no root node, such as List and Array objects.

The default value is true.

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 showRoot():Boolean
    public function set showRoot(value:Boolean):void

source

property 
source:IHierarchicalData

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The source data of the IHierarchicalCollectionView.



Implementation
    public function get source():IHierarchicalData
    public function set source(value:IHierarchicalData):void
Constructor Detail

HierarchicalCollectionView

()Constructor
public function HierarchicalCollectionView(hierarchicalData:IHierarchicalData = null, argOpenNodes:Object = null)

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Constructor.

Parameters
hierarchicalData:IHierarchicalData (default = null) — The data structure containing the hierarchical data.
 
argOpenNodes:Object (default = null) — The Object that defines a node to appear as open.
Method Detail

addChild

()method
public function addChild(parent:Object, newChild:Object):Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Adds a child node to a node of the data.

Parameters

parent:Object — The Object that defines the parent node.
 
newChild:Object — The Object that defines the new node.

Returns
Booleantrue if the node is added successfully.

addChildAt

()method 
public function addChildAt(parent:Object, newChild:Object, index:int):Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Add a child node to a node at the specified index. This implementation does the following:

  • If the parent is null or undefined, inserts the child at the specified index in the collection specified by source.
  • If the parent has a children field or property, the method adds the child to it at the index location. In this case, the source is not required.
  • If the parent does not have a children field or property, the method adds the children to the parent. The method then adds the child to the parent at the index location. In this case, the source is not required.
  • If the index value is greater than the collection length or number of children in the parent, adds the object as the last child.

Parameters

parent:Object — The Object that defines the parent node.
 
newChild:Object — The Object that defines the child node.
 
index:int — The 0-based index of where to insert the child node.

Returns
Booleantrue if the child is added successfully.

closeNode

()method 
public function closeNode(node:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Closes a node to hide its children.

Parameters

node:Object — The Object that defines the node.

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

Checks the collection for the data item using standard equality test.

Parameters

item:Object — The Object that defines the node to look for.

Returns
Booleantrue if the data item is in the collection, and false if not.

createCursor

()method 
public function createCursor():IViewCursor

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Returns a new instance of a view iterator over the items in this view.

Returns
IViewCursor — IViewCursor instance.

See also

mx.utils.IViewCursor

getChildren

()method 
public function getChildren(node:Object):ICollectionView

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Returns a collection of children, if they exist.

Parameters

node:Object — The Object that defines the node. If null, return a collection of top level nodes.

Returns
ICollectionView — ICollectionView instance containing the child nodes.

getNodeDepth

()method 
public function getNodeDepth(node:Object):int

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Returns the depth of the node in the collection.

Parameters

node:Object — The Object that defines the node.

Returns
int — The depth of the node.

getParentItem

()method 
public function getParentItem(node:Object):*

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Returns the parent of a node. The parent of a top-level node is null.

Parameters

node:Object — The Object that defines the node.

Returns
* — The parent node containing the node, null for a top-level node, and undefined if the parent cannot be determined.

openNode

()method 
public function openNode(node:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Opens a node to display its children.

Parameters

node:Object — The Object that defines the node.

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
Booleantrue if the refresh() was complete, false if the refresh() is incomplete.

removeChild

()method 
public function removeChild(parent:Object, child:Object):Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Removes the child node from the parent node.

Parameters

parent:Object — The Object that defines the parent node, and null for top-level nodes.
 
child:Object — The Object that defines the child node to be removed.

Returns
Booleantrue if the node is removed successfully.

removeChildAt

()method 
public function removeChildAt(parent:Object, index:int):Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Removes the child node from a node at the specified index.

Parameters

parent:Object — The Object that defines the parent node.
 
index:int — The 0-based index of the child node to remove relative to the parent.

Returns
Booleantrue if the child is removed successfully.

xmlNotification

()method 
public function xmlNotification(currentTarget:Object, type:String, target:Object, value:Object, detail:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Called whenever an XML object contained in our list is updated in some way. The initial implementation stab is very lenient, any changeType will cause an update no matter how much further down in a hierarchy.

Parameters

currentTarget:Object
 
type:String
 
target:Object
 
value:Object
 
detail:Object