| Package | mx.collections |
| Class | public class SortField |
| Inheritance | SortField  EventDispatcher Object |
| Implements | ISortField |
| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
 | Starting with Flex 4.5, Adobe recommends that you use the spark.collections.SortField class as an alternative to this class. |
Provides the sorting information required to establish a sort on a field or property in a collection view. The SortField class is meant to be used with the Sort class. 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;
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;
By default the comparison provided by the SortField class does
not provide correct language specific
sorting for strings. For this type of sorting please see the
spark.collections.Sort and
spark.collections.SortField classes.
Show MXML Syntax
Hide MXML SyntaxThe <mx:SortField> tag has the following attributes:
<mx:SortField Properties caseInsensitive="false" compareFunction="Internal compare function" descending="false" name="null" numeric="null" />
Related API Elements
| Property | Defined By | ||
|---|---|---|---|
| arraySortOnOptions : int [read-only]
This helper property is used internally by the findItem()
and sort() methods. | SortField | ||
| 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 | ||
 | constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | |
| descending : Boolean
Specifies whether 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 comparator use a numeric comparison. | SortField | ||
| usingCustomCompareFunction : Boolean [read-only]
True if this ISortField uses a custom comparator function. | SortField | ||
| Method | Defined By | ||
|---|---|---|---|
SortField(name:String = null, caseInsensitive:Boolean = false, descending:Boolean = false, numeric:Object = null)
Constructor. | SortField | ||
| addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener
receives notification of an event. | EventDispatcher | |
|
Dispatches an event into the event flow. | EventDispatcher | |
|
Checks whether the EventDispatcher object has any listeners registered for a specific type
of event. | EventDispatcher | |
|
Indicates whether an object has a specified property defined. | Object | |
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. | SortField | ||
|
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
|
Indicates whether the specified property exists and is enumerable. | Object | |
|
Removes a listener from the EventDispatcher object. | EventDispatcher | |
Reverse the criteria for this sort field. | SortField | ||
|
Sets the availability of a dynamic property for loop operations. | Object | |
|
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
|
Returns the string representation of the specified object. | Object | |
|
Returns the primitive value of the specified object. | Object | |
|
Checks whether an event listener is registered with this EventDispatcher object or any of
its ancestors for the specified event type. | EventDispatcher | |
arraySortOnOptions | property |
arraySortOnOptions:int [read-only] | Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| 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():intcaseInsensitive | property |
caseInsensitive:Boolean| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
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. When this property is modified, it dispatches the caseInsensitiveChanged event.
Implementation
public function get caseInsensitive():Boolean public function set caseInsensitive(value:Boolean):voidcompareFunction | property |
compareFunction:Function| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| 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 SortField
objects.
The compare function must have the following signature:
function myCompare(a:Object, b:Object):int
This function must return the following values:
- -1, if
ashould appear beforebin the sorted sequence - 0, if
aequalsb - 1, if
ashould appear afterbin the sorted sequence
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.
Note if you need, language specific sorting then consider using thespark.collections.SortField class.
Implementation
public function get compareFunction():Function public function set compareFunction(value:Function):voidRelated API Elements
descending | property |
descending:Boolean| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Specifies whether 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. When this property is modified, it dispatches the descendingChanged event.
Implementation
public function get descending():Boolean public function set descending(value:Boolean):voidname | property |
name:String| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
The name of the field to be sorted.
The default value is null.
This property can be used as the source for data binding. When this property is modified, it dispatches the nameChanged event.
Implementation
public function get name():String public function set name(value:String):voidnumeric | property |
numeric:Object| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| 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.
This property can be used as the source for data binding. When this property is modified, it dispatches the numericChanged event.
Implementation
public function get numeric():Object public function set numeric(value:Object):voidusingCustomCompareFunction | property |
SortField | () | Constructor |
public function SortField(name:String = null, caseInsensitive:Boolean = false, descending:Boolean = false, numeric:Object = null)| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Constructor.
Parametersname:String (default = null)null.
| |
caseInsensitive:Boolean (default = false) | |
descending:Boolean (default = false) | |
numeric:Object (default = null) |
initializeDefaultCompareFunction | () | method |
public function initializeDefaultCompareFunction(obj:Object):void| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| 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 3 |
| 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.
Wed Nov 21 2018, 06:34 AM -08:00