Packagemx.collections
Classpublic class SortField
InheritanceSortField Inheritance flash.events.EventDispatcher

Provides the sorting information required to establish a sort on a field or property in an existing view. Typically the sort is defined for collections of complex items, that is items in which the sort is performed on properties of those objects. As in the following example: 

     var col:ICollectionView = new ArrayCollection();
     col.addItem({first:"Anders", last:"Dickerson"});
     var sort:Sort = new Sort();
     sort.fields = [new SortField("first", true)];
     col.sort = sort;
There are situations in which the collection contains simple items, like String, Date, Boolean, etc. In this case, sorting should be applied to the simple type directly. When constructing a sort for this situation only a single sort field is required and should not have a name specified. For example: 

     var col:ICollectionView = new ArrayCollection();
     col.addItem("California");
     col.addItem("Arizona");
     var sort:Sort = new Sort();
     sort.fields = [new SortField(null, true)];
     col.sort = sort;

MXML Syntaxexpanded Hide MXML Syntax

The <mx:SortField> tag has the following attributes:

  <mx:SortField
  Properties
  caseInsensitive="false"
  compareFunction="Internal compare function"
  descending="false"
  name="null"
  numeric="null"
  />

Public Properties
 PropertyDefined by
  caseInsensitive : Boolean
Specifies whether the sort for this field should be case insensitive.
SortField
  compareFunction : Function
The function that compares two items during a sort of items for the associated collection.
SortField
  descending : Boolean
Specifies whether the this field should be sorted in descending order.
SortField
  name : String
The name of the field to be sorted.
SortField
  numeric : Object
Specifies that if the field being sorted contains numeric (number/int/uint) values, or string representations of numeric values, the comparitor use a numeric comparison.
SortField
Public Methods
 MethodDefined by
  
SortField(name:String = null, caseInsensitive:Boolean = false, descending:Boolean = false, numeric:Object = null)
Constructor.
SortField
  
reverse():void
Reverse the criteria for this sort field.
SortField
Property detail
caseInsensitiveproperty
caseInsensitive:Boolean  [read-write]

Specifies whether the sort for this field should be case insensitive.

The default value is false.

This property can be used as the source for data binding.

Implementation
    public function get caseInsensitive():Boolean
    public function set caseInsensitive(value:Boolean):void
compareFunctionproperty 
compareFunction:Function  [read-write]

The function that compares two items during a sort of items for the associated collection. If you specify a compareFunction property in a Sort object, Flex ignores any compareFunction properties of the Sort's SortField objects.

The compare function must have the following signature:

function myCompare(a:Object, b:Object):int

This function must return the following values:

The default value is an internal compare function that can perform a string, numeric, or date comparison in ascending or descending order, with case-sensitive or case-insensitive string comparisons. Specify your own function only if you need a need a custom comparison algorithm. This is normally only the case if a calculated field is used in a display.

Implementation
    public function get compareFunction():Function
    public function set compareFunction(value:Function):void
descendingproperty 
descending:Boolean  [read-write]

Specifies whether the this field should be sorted in descending order.

The default value is false (ascending).

This property can be used as the source for data binding.

Implementation
    public function get descending():Boolean
    public function set descending(value:Boolean):void
nameproperty 
name:String  [read-write]

The name of the field to be sorted.

The default value is null.

This property can be used as the source for data binding.

Implementation
    public function get name():String
    public function set name(value:String):void
numericproperty 
numeric:Object  [read-write]

Specifies that if the field being sorted contains numeric (number/int/uint) values, or string representations of numeric values, the comparitor use a numeric comparison. If this property is false, fields with string representations of numbers are sorted using strings comparison, so 100 precedes 99, because "1" is a lower string value than "9". If this property is null, the first data item is introspected to see if it is a number or string and the sort proceeds based on that introspection

The default value is false.

This property can be used as the source for data binding.

Implementation
    public function get numeric():Object
    public function set numeric(value:Object):void
Constructor detail
SortField()constructor
public function SortField(name:String = null, caseInsensitive:Boolean = false, descending:Boolean = false, numeric:Object = null)

Constructor.

Parameters
name:String (default = null) — The name of the property that this field uses for comparison. If the object is a simple type, pass null.
 
caseInsensitive:Boolean (default = false) — When sorting strings, tells the comparitor whether to ignore the case of the values.
 
descending:Boolean (default = false) — Tells the comparator whether to arrange items in descending order.
 
numeric:Object (default = null) — Tells the comparitor whether to compare sort items as numbers, instead of alphabetically.
Method detail
reverse()method
public function reverse():void

Reverse the criteria for this sort field. If the field was sorted in descending order, for example, sort it in ascending order.

Note: an ICollectionView does not automatically update when the SortFields are modified; call its refresh() method to update the view.




(c) Copyright 2010 DWUser.com - http://www.dwuser.com/flashslideshow/