Adobe® Flex® 4 Language Reference
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mx.controls.treeClasses 
DefaultDataDescriptor 
Packagemx.controls.treeClasses
Classpublic class DefaultDataDescriptor
InheritanceDefaultDataDescriptor Inheritance Object
Implements ITreeDataDescriptor2, IMenuDataDescriptor

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

The DefaultDataDescriptor class provides a default implementation for accessing and manipulating data for use in controls such as Tree and Menu. 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. This class is the default value of the Tree, Menu, MenuBar, and PopUpMenuButton control dataDescriptor properties.

See also



Public Properties
 PropertyDefined By
 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
Public Methods
 MethodDefined By
  
Constructor.
DefaultDataDescriptor
  
addChildAt(parent:Object, newChild:Object, index:int, model:Object = null):Boolean
Add a child node to a node at the specified index.
DefaultDataDescriptor
  
Provides access to a node's children.
DefaultDataDescriptor
  
getData(node:Object, model:Object = null):Object
Returns a node's data.
DefaultDataDescriptor
  
Returns the name of the radio button group to which the node belongs, if any.
DefaultDataDescriptor
  
getHierarchicalCollectionAdaptor(hierarchicalData:ICollectionView, uidFunction:Function, openItems:Object, model:Object = null):ICollectionView
Returns an ICollectionView instance that makes the hierarchical data appear as if it was a linear ICollectionView instance.
DefaultDataDescriptor
  
getNodeDepth(node:Object, iterator:IViewCursor, model:Object = null):int
Returns the depth of the node, meaning the number of ancestors it has.
DefaultDataDescriptor
  
getParent(node:Object, collection:ICollectionView, model:Object = null):Object
Returns the parent of the node The parent of a top-level node is null.
DefaultDataDescriptor
  
Returns the type identifier of a node.
DefaultDataDescriptor
  
hasChildren(node:Object, model:Object = null):Boolean
Determines if the node actually has children.
DefaultDataDescriptor
 Inherited
Indicates whether an object has a specified property defined.
Object
  
isBranch(node:Object, model:Object = null):Boolean
Tests a node for termination.
DefaultDataDescriptor
  
Returns whether the node is enabled.
DefaultDataDescriptor
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
  
Returns whether the node is toggled.
DefaultDataDescriptor
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
  
removeChildAt(parent:Object, child:Object, index:int, model:Object = null):Boolean
Removes the child node from a node at the specified index.
DefaultDataDescriptor
  
Sets the value of the field or attribute in the data provider that identifies whether the node is enabled.
DefaultDataDescriptor
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
  
Sets the value of the field or attribute in the data provider that identifies whether the node is toggled.
DefaultDataDescriptor
 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
Constructor Detail

DefaultDataDescriptor

()Constructor
public function DefaultDataDescriptor()

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

Constructor.

Method Detail

addChildAt

()method
public function addChildAt(parent:Object, newChild:Object, index:int, model:Object = null):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 parameter is null or undefined, inserts the child parameter at the specified index in the collection specified by model parameter.
  • If the parent parameter has a children field or property, the method adds the child parameter to it at the index parameter location. In this case, the model parameter is not required.
  • If the parent parameter does not have a children field or property, the method adds the children property to the parent. The method then adds the child parameter to the parent at the index parameter location. In this case, the model parameter 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 node object that will parent the child.
 
newChild:Object — The node object that will be parented by the node.
 
index:int — The 0-based index of where to put the child node relative to the parent.
 
model:Object (default = null) — The entire collection that this node is a part of.

Returns
Booleantrue if successful.

getChildren

()method 
public function getChildren(node:Object, model:Object = null):ICollectionView

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

Provides access to a node's children. Returns a collection of children if they exist. If the node is an Object, the method returns the contents of the object's children field as an ArrayCollection. If the node is XML, the method returns an XMLListCollection containing the child elements.

Parameters

node:Object — The node object currently being evaluated.
 
model:Object (default = null) — The collection that contains the node; ignored by this class.

Returns
ICollectionView — An object containing the children nodes.

getData

()method 
public function getData(node:Object, model:Object = null):Object

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

Returns a node's data. Currently returns the entire node.

Parameters

node:Object — The node object currently being evaluated.
 
model:Object (default = null) — The collection that contains the node; ignored by this class.

Returns
Object — The node.

getGroupName

()method 
public function getGroupName(node:Object):String

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

Returns the name of the radio button group to which the node belongs, if any. This method is used by menu-based controls.

Parameters

node:Object — The node for which to get the group name.

Returns
String — The value of the node's groupName attribute or field, or an empty string if there is no such entry.

getHierarchicalCollectionAdaptor

()method 
public function getHierarchicalCollectionAdaptor(hierarchicalData:ICollectionView, uidFunction:Function, openItems:Object, model:Object = null):ICollectionView

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

Returns an ICollectionView instance that makes the hierarchical data appear as if it was a linear ICollectionView instance.

Parameters

hierarchicalData:ICollectionView — The hierarchical data.
 
uidFunction:Function — A function that takes an Object and returns the UID, as a String. This parameter is usually the Tree.itemToUID() method.
 
openItems:Object — The items that have been opened or set opened.
 
model:Object (default = null) — The collection to which this node belongs.

Returns
ICollectionView — An ICollectionView instance.

getNodeDepth

()method 
public function getNodeDepth(node:Object, iterator:IViewCursor, model:Object = null):int

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

Returns the depth of the node, meaning the number of ancestors it has.

Parameters

node:Object — The Object that defines the node.
 
iterator:IViewCursor — An IViewCursor instance that could be used to do the calculation.
 
model:Object (default = null) — The collection to which this node belongs.

Returns
int — The depth of the node, where 0 corresponds to the top level, and -1 if the depth cannot be calculated.

getParent

()method 
public function getParent(node:Object, collection:ICollectionView, model:Object = null):Object

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

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

Parameters

node:Object — The Object that defines the node.
 
collection:ICollectionView — An ICollectionView instance that could be used to do the calculation.
 
model:Object (default = null) — The collection to which this node belongs.

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

getType

()method 
public function getType(node:Object):String

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

Returns the type identifier of a node. This method is used by menu-based controls to determine if the node represents a separator, radio button, a check box, or normal item.

Parameters

node:Object — The node object for which to get the type.

Returns
String — The value of the type attribute or field, or the empty string if there is no such field.

hasChildren

()method 
public function hasChildren(node:Object, model:Object = null):Boolean

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

Determines if the node actually has children.

Parameters

node:Object — The node object currently being evaluated.
 
model:Object (default = null) — The collection that contains the node; ignored by this class.

Returns
Booleantrue if this node currently has children.

isBranch

()method 
public function isBranch(node:Object, model:Object = null):Boolean

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

Tests a node for termination. Branches are non-terminating but are not required to have any leaf nodes. If the node is XML, returns true if the node has children or a true isBranch attribute. If the node is an object, returns true if the node has a (possibly empty) children field.

Parameters

node:Object — The node object currently being evaluated.
 
model:Object (default = null) — The collection that contains the node; ignored by this class.

Returns
Booleantrue if this node is non-terminating.

isEnabled

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

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

Returns whether the node is enabled. This method is used by menu-based controls.

Parameters

node:Object — The node for which to get the status.

Returns
Boolean — The value of the node's enabled attribute or field, or true if there is no such entry or the value is not false.

isToggled

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

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

Returns whether the node is toggled. This method is used by menu-based controls.

Parameters

node:Object — The node for which to get the status.

Returns
Boolean — The value of the node's toggled attribute or field, or false if there is no such entry.

removeChildAt

()method 
public function removeChildAt(parent:Object, child:Object, index:int, model:Object = null):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. If the parent parameter is null or undefined, the method uses the model parameter to access the child; otherwise, it uses the parent parameter and ignores the model parameter.

Parameters

parent:Object — The node object that currently parents the child node.
 
child:Object — The node that is being removed.
 
index:int — The 0-based index of the child node to remove relative to the parent.
 
model:Object (default = null) — The entire collection that this node is a part of.

Returns
Booleantrue if successful.

setEnabled

()method 
public function setEnabled(node:Object, value:Boolean):void

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

Sets the value of the field or attribute in the data provider that identifies whether the node is enabled. This method sets the value of the node's enabled attribute or field. This method is used by menu-based controls.

Parameters

node:Object — The node for which to set the status.
 
value:Boolean — Whether the node is enabled.

setToggled

()method 
public function setToggled(node:Object, value:Boolean):void

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

Sets the value of the field or attribute in the data provider that identifies whether the node is toggled. This method sets the value of the node's toggled attribute or field. This method is used by menu-based controls.

Parameters

node:Object — The node for which to set the status.
 
value:Boolean — Whether the node is toggled.