Adobe® Flex® 4 Language Reference
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mx.collections 
HierarchicalData 
Packagemx.collections
Classpublic class HierarchicalData
InheritanceHierarchicalData Inheritance EventDispatcher Inheritance Object
Implements IHierarchicalData
Subclasses GroupingCollection, GroupingCollection2

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

Hierarchical data is data already in a structure of parent and child data items. The HierarchicalData class provides a default implementation for accessing and manipulating data for use in controls such as the AdvancedDataGrid control. To configure the AdvancedDataGrid control to display hierarchical data, you pass to the dataProvider property an instance of the HierarchicalData class. This implementation handles E4X, XML, and Object nodes in similar but different ways. See each method description for details on how the method accesses values in nodes of various types.

See also



Public Properties
 PropertyDefined By
  childrenField : String
Indicates the field name to be used to detect children objects in a data item.
HierarchicalData
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  source : Object
The source collection.
HierarchicalData
Public Methods
 MethodDefined By
  
HierarchicalData(value:Object = null)
Constructor.
HierarchicalData
 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
  
Returns true if the node can contain children.
HierarchicalData
 Inherited
Dispatches an event into the event flow.
EventDispatcher
  
Returns an Object representing the node's children.
HierarchicalData
  
Returns data from a node.
HierarchicalData
  
Returns the root data item.
HierarchicalData
  
Returns true if the node has children.
HierarchicalData
 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
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 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
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

childrenField

property
childrenField:String

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

Indicates the field name to be used to detect children objects in a data item. By default, all subnodes are considered as children for XML data, and the children property is used for the Object data type. This is helpful in adapting to a data format that uses custom data fields to represent children.



Implementation
    public function get childrenField():String
    public function set childrenField(value:String):void

source

property 
source:Object

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

The source collection. The collection should implement the IList interface to facilitate operation like the addition and removal of items.



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

See also

Constructor Detail

HierarchicalData

()Constructor
public function HierarchicalData(value:Object = null)

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

Constructor.

Parameters
value:Object (default = null) — The data used to populate the HierarchicalData instance.
Method Detail

canHaveChildren

()method
public function canHaveChildren(node:Object):Boolean

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

Returns true if the node can contain children.

Nodes do not have to contain children for the method to return true. This method is useful in determining whether other nodes can be appended as children to the specified node.

Parameters

node:Object — The Object that defines the node.

Returns
Booleantrue if the node can contain children.

getChildren

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

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

Returns an Object representing the node's children.

Parameters

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

Returns
Object — An Object containing the children nodes.

getData

()method 
public function getData(node:Object):Object

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

Returns data from a node.

Parameters

node:Object — The node Object from which to get the data.

Returns
Object — The requested data.

getRoot

()method 
public function getRoot():Object

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

Returns the root data item.

Returns
Object — The Object containing the root data item.

hasChildren

()method 
public function hasChildren(node:Object):Boolean

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

Returns true if the node has children.

Parameters

node:Object — The Object that defines the node.

Returns
Booleantrue if the node has children.