ActionScript® 3.0 Reference for the Adobe® Flash® Platform
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mx.collections 

ISortField  - AS3 Flex

Packagemx.collections
Interfacepublic interface ISortField
Implementors SortField, SortField

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

The ISortField interface defines the interface for classes that are used with ISort classes, to provide the sorting information required to sort the specific fields or property in a collection view.



Public Properties
 PropertyDefined By
  arraySortOnOptions : int
[read-only] This helper property is used internally by the findItem() and sort() methods.
ISortField
  compareFunction : Function
The function that compares two items during a sort of items for the associated collection.
ISortField
  descending : Boolean
Specifies whether this field should be sorted in descending order.
ISortField
  name : String
The name of the field to be sorted.
ISortField
  numeric : Object
Specifies that if the field being sorted contains numeric (number/int/uint) values, or string representations of numeric values, the comparator use a numeric comparison.
ISortField
  usingCustomCompareFunction : Boolean
[read-only] True if this ISortField uses a custom comparator function.
ISortField
Public Methods
 MethodDefined By
  
A helper function called by the Sort class to set the default comparison function to perform a comparison based on one of three things: whether or not a custom compare function has been set, the data type for the specified field or the the value of the numeric property.
ISortField
  
Reverse the criteria for this sort field.
ISortField
Property Detail

arraySortOnOptions

property
arraySortOnOptions:int  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

This helper property is used internally by the findItem() and sort() methods. Other uses of this property are not supported. Returns -1 if this ISortField shouldn't be used by the Sort class to sort the field (there is no compareFunction or no name). Otherwise, returns a bitmask of sort options..



Implementation
    public function get arraySortOnOptions():int

compareFunction

property 
compareFunction:Function

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

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

The compare function must have the following signature:

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

This function returns the following values:

  • -1, if a should appear before b in the sorted sequence
  • 0, if a equals b
  • 1, if a should appear after b in the sorted sequence


Implementation
    public function get compareFunction():Function
    public function set compareFunction(value:Function):void

descending

property 
descending:Boolean

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

Specifies whether this field should be sorted in descending order.

The default value is false (ascending).



Implementation
    public function get descending():Boolean
    public function set descending(value:Boolean):void

name

property 
name:String

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

The name of the field to be sorted.



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

numeric

property 
numeric:Object

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

Specifies that if the field being sorted contains numeric (number/int/uint) values, or string representations of numeric values, the comparator use a numeric comparison.

This property is used by SortField class in case custom compare function is not provided.

If this property is true, the built-in numeric compare function is used. Each of data items is cast to a Number() function before the comparison.

If this property is false, the built-in string compare function is used. Each of data items is cast to a String() function before the comparison.

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 null.



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

usingCustomCompareFunction

property 
usingCustomCompareFunction:Boolean  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

True if this ISortField uses a custom comparator function.



Implementation
    public function get usingCustomCompareFunction():Boolean
Method Detail

initializeDefaultCompareFunction

()method
public function initializeDefaultCompareFunction(obj:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

A helper function called by the Sort class to set the default comparison function to perform a comparison based on one of three things: whether or not a custom compare function has been set, the data type for the specified field or the the value of the numeric property. If the the numeric property is true, then a numeric comparison will be performed when sorting.

Parameters

obj:Object — The object that contains the data. If the field name has been set with the name property, then the name will be used to access the data value from this object. Otherwise the object itself will be used as the data value.

reverse

()method 
public function reverse():void

Language Version: ActionScript 3.0
Product Version: Flex 4.5
Runtime Versions: Flash Player 9, AIR 1.1

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 ISortFields are modified; call its refresh() method to update the view.