mx.collections

# ISortField - AS3 Flex

Package | mx.collections
Interface | public 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

| Property | Defined 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

| Method | Defined By
--- | --- | ---
|  | initializeDefaultCompareFunction(obj:Object):void 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():void 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.

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Mon Apr 10 2017, 12:28 PM -07:00