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NSTreeNode Class Reference

Overview

NSTreeNode simplifies the creation and management of trees of objects. Each tree node represents a model object. A tree node with nil as its parent node is considered the root of the tree.

Tasks

Creating Tree Nodes

• + treeNodeWithRepresentedObject:
• – initWithRepresentedObject:

Getting Information About a Node

• – representedObject
• – indexPath
• – isLeaf
• – childNodes
• – mutableChildNodes
• – descendantNodeAtIndexPath:
• – parentNode

Sorting the Subtree

• – sortWithSortDescriptors:recursively:

Class Methods

treeNodeWithRepresentedObject:

Creates and returns a tree node that represents the specified object.

+ (id)treeNodeWithRepresentedObject:(id)modelObject

Parameters

modelObject

The object the tree node represents.

Return Value

An initialized tree node that represents modelObject.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

Instance Methods

childNodes

Returns an array containing receiver’s child nodes.

- (NSArray *)childNodes

Return Value

An array containing the receiver’s child nodes.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

descendantNodeAtIndexPath:

Returns the receiver’s descendent at the specified index path.

- (NSTreeNode *)descendantNodeAtIndexPath:(NSIndexPath *)indexPath

Parameters

indexPath

An index path specifying a descendent of the receiver.

Return Value

A tree node, or nil if the node does not exist.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

indexPath

Returns the position of the receiver relative to its root parent.

- (NSIndexPath *)indexPath

Return Value

An index path that represents the receiver’s position relative to the tree’s root node.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

initWithRepresentedObject:

Initializes a newly allocated tree node that represents the specified object.

- (id)initWithRepresentedObject:(id)modelObject

Parameters

modelObject

The object the tree node represents.

Return Value

An initialized tree node that represents modelObject.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

isLeaf

Returns whether the receiver is a leaf node.

- (BOOL)isLeaf

Return Value

YES if the receiver is a leaf node (has no child nodes), otherwise NO.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

mutableChildNodes

Returns a mutable array that provides read-write access to the receiver’s child nodes.

- (NSMutableArray *)mutableChildNodes

Return Value

A mutable array that provides read-write access to the receiver’s child nodes.

Discussion

Nodes that are inserted into this array have their parent nodes set to the receiver. Nodes that are removed from this array automatically have their parent node set to nil. The array that is returned is observable using key-value observing.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

parentNode

Returns the receiver’s parent node.

- (NSTreeNode *)parentNode

Return Value

The receiver’s parent node.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

representedObject

Returns the object the tree node represents.

- (id)representedObject

Return Value

The object the tree node represents.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

sortWithSortDescriptors:recursively:

Sorts the receiver’s subtree using the values of the represented objects with the specified sort descriptors.

- (void)sortWithSortDescriptors:(NSArray *)sortDescriptors recursively:(BOOL)recursively

Parameters

sortDescriptors

Array of sort descriptors specifying how to sort the represented objects.

recursively

A Boolean that specifies whether the child nodes should be sorted recursively.

Discussion

All the represented objects in the child nodes must be key-value coding compliant for the keys specified in the sort descriptors.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

NSTreeNode.h

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