mx.validators.RegExpValidator - Adobe® Flex® 4 Language Reference (Flex 4)

Package	mx.validators
Class	public class RegExpValidator
Inheritance	RegExpValidator Validator EventDispatcher Object

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The RegExpValidator class lets you use a regular expression to validate a field. You pass a regular expression to the validator using the expression property, and additional flags to control the regular expression pattern matching using the flags property.

The validation is successful if the validator can find a match of the regular expression in the field to validate. A validation error occurs when the validator finds no match.

The RegExpValidator class dispatches the valid and invalid events. For an invalid event, the event object is an instance of the ValidationResultEvent class, and it contains an Array of ValidationResult objects.

However, for a valid event, the ValidationResultEvent object contains an Array of RegExpValidationResult objects. The RegExpValidationResult class is a child class of the ValidationResult class, and contains additional properties used with regular expressions, including the following:

matchedIndex An integer that contains the starting index in the input String of the match.
matchedString A String that contains the substring of the input String that matches the regular expression.
matchedSubStrings An Array of Strings that contains parenthesized substring matches, if any. If no substring matches are found, this Array is of length 0. Use matchedSubStrings[0] to access the first substring match.

MXML Syntax expanded

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The <mx:RegExpValidator> tag inherits all of the tag attributes of its superclass, and adds the following tag attributes:

  <mx:RegExpValidator
    expression="No default" 
    flags="No default" 
    noExpressionError="The expression is missing." 
    noMatchError="The field is invalid." 
  />

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Public Properties

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	Property		Defined By
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		enabled : Boolean Setting this value to false will stop the validator from performing validation.	Validator
		expression : String The regular expression to use for validation.	RegExpValidator
		flags : String The regular expression flags to use when matching.	RegExpValidator
		listener : Object Specifies the validation listener.	Validator
		noExpressionError : String Error message when there is no regular expression specifed.	RegExpValidator
		noMatchError : String Error message when there are no matches to the regular expression.	RegExpValidator
		property : String A String specifying the name of the property of the source object that contains the value to validate.	Validator
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		required : Boolean = true If true, specifies that a missing or empty value causes a validation error.	Validator
		requiredFieldError : String Error message when a value is missing and the required property is true.	Validator
		source : Object Specifies the object containing the property to validate.	Validator
		trigger : IEventDispatcher Specifies the component generating the event that triggers the validator.	Validator
		triggerEvent : String Specifies the event that triggers the validation.	Validator

Protected Properties

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	Property		Defined By
		actualListeners : Array [read-only] Contains an Array of listener objects, if any, or the source object.	Validator
		actualTrigger : IEventDispatcher [read-only] Contains the trigger object, if any, or the source object.	Validator
		resourceManager : IResourceManager [read-only] A reference to the object which manages all of the application's localized resources.	Validator
		subFields : Array An Array of Strings containing the names for the properties contained in the value Object passed to the validate() method.	Validator

Public Methods

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	Method		Defined By
		RegExpValidator() Constructor	RegExpValidator
		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
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	EventDispatcher
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		initialized(document:Object, id:String):void Called automatically by the MXML compiler when the Validator is created using an MXML tag.	Validator
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	EventDispatcher
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		validate(value:Object = null, suppressEvents:Boolean = false):ValidationResultEvent Performs validation and optionally notifies the listeners of the result.	Validator
		validateAll(validators:Array):Array [static] Invokes all the validators in the validators Array.	Validator
		valueOf():Object Returns the primitive value of the specified object.	Object
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	EventDispatcher

Protected Methods

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	Method		Defined By
		addListenerHandler():void Sets up all of the listeners for the valid and invalid events dispatched from the validator.	Validator
		doValidation(value:Object):Array [override] Override of the base class doValidation() method to validate a regular expression.	RegExpValidator
		getValueFromSource():Object Returns the Object to validate.	Validator
		handleResults(errorResults:Array):ValidationResultEvent Returns a ValidationResultEvent from the Array of error results.	Validator
		isRealValue(value:Object):Boolean Returns true if value is not null.	Validator
		removeListenerHandler():void Disconnects all of the listeners for the valid and invalid events dispatched from the validator.	Validator
		resourcesChanged():void This method is called when a Validator is constructed, and again whenever the ResourceManager dispatches a "change" Event to indicate that the localized resources have changed in some way.	Validator

Events

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	Summary	Defined By
activate	[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.	EventDispatcher
deactivate	[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.	EventDispatcher
invalid	Dispatched when validation fails.	Validator
valid	Dispatched when validation succeeds.	Validator

Protected Constants

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	Constant		Defined By
		DECIMAL_DIGITS : String = "0123456789" [static] A String containing the decimal digits 0 through 9.	Validator
		ROMAN_LETTERS : String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" [static] A string containing the upper- and lower-case letters of the Roman alphabet ("A" through "Z" and "a" through "z").	Validator

Property Detail

expression

property

expression:String

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The regular expression to use for validation.

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

flags

property

flags:String

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The regular expression flags to use when matching.

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

noExpressionError

property

noExpressionError:String

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Error message when there is no regular expression specifed. The default value is "The expression is missing."

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

noMatchError

property

noMatchError:String

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Error message when there are no matches to the regular expression. The default value is "The field is invalid."

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

Constructor Detail

RegExpValidator

()

Constructor

public function RegExpValidator()

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constructor

Method Detail

doValidation

()

method

override protected function doValidation(value:Object):Array

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Override of the base class doValidation() method to validate a regular expression.

You do not call this method directly; Flex calls it as part of performing a validation. If you create a custom Validator class, you must implement this method.

Parameters

value:Object — Object to validate.

Returns

Array — For an invalid result, an Array of ValidationResult objects, with one ValidationResult object for each field examined by the validator.

Examples ( How to use this example )

RegExValidatorExample.mxml

<?xml version="1.0" encoding="utf-8"?>
<!-- Simple example to demonstrate the RegExpValidator. -->
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">

    <fx:Script>
        <![CDATA[
            import mx.events.ValidationResultEvent;
            import mx.validators.*;

            // Write the results to the 
            private function handleResult(eventObj:ValidationResultEvent):void {
                if (eventObj.type == ValidationResultEvent.VALID) {
                    // For valid events, the results Array contains
                    // RegExpValidationResult objects.
                    var xResult:RegExpValidationResult;
                    reResults.text = "";
                    for (var i:uint = 0; i < eventObj.results.length; i++) {
                        xResult = eventObj.results[i];
                        reResults.text=reResults.text + xResult.matchedIndex + " " + xResult.matchedString + "\n";
                    }
                } else {
                    reResults.text = "";
                }
            }
        ]]>
    </fx:Script>

    <fx:Declarations>
        <mx:RegExpValidator id="regExpV" 
                source="{regex_text}" property="text" 
                flags="g" expression="{regex.text}" 
                valid="handleResult(event)"
                invalid="handleResult(event)"
                trigger="{myButton}"
                triggerEvent="click"/>
    </fx:Declarations>

    <s:Panel title="RegExpValidator Example"
            width="75%" height="75%"
            horizontalCenter="0" verticalCenter="0">
        <s:VGroup left="10" right="10" top="10" bottom="10">
            <s:Label width="100%" text="Instructions:"/>
            <s:Label width="100%" text="1. Enter text to search. By default, enter  a string containing the letters ABC in sequence followed by any digit."/>
            <s:Label width="100%" text="2. Enter the regular expression. By default, enter ABC\d."/>
            <s:Label width="100%" text="3. Click the Button control to trigger the validation."/>
            <s:Label width="100%" text="4. The results show the index in the text where the matching pattern begins, and the matching pattern. "/>
            <mx:Form>
                <mx:FormItem label="Enter text:">
                    <s:TextInput id="regex_text" text="xxxxABC4xxx" width="100%"/>
                </mx:FormItem>
                <mx:FormItem label="Enter regular expression:">
                    <s:TextInput id="regex" text="ABC\d" width="100%"/>
                </mx:FormItem>
                <mx:FormItem label="Results:">
                    <s:TextInput id="reResults" width="100%"/>
                </mx:FormItem>
                <mx:FormItem >
                    <s:Button id="myButton" label="Validate"/>
                </mx:FormItem>
            </mx:Form>
        </s:VGroup>
    </s:Panel>

</s:Application>