| Package | mx.validators |
| Class | public class StringValidator |
| Inheritance | StringValidator  Validator EventDispatcher Object |
| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Show MXML Syntax
Hide MXML SyntaxThe <mx:StringValidator> tag
inherits all of the tag attributes of its superclass,
and add the following tag attributes:
<mx:StringValidator
maxLength="NaN"
minLength="NaN"
tooLongError="This string is longer than the maximum allowed length. This must be less than {0} characters long."
tooShortError="This string is shorter than the minimum allowed length. This must be at least {0} characters long."
/>
More examples
Learn more
Validating data
About the source and property properties
About triggering validation
Triggering validation by using events
Triggering validation programmatically
Validating required fields
General guidelines for validation
Working with validation errors
Working with validation events
About the source and property properties
About triggering validation
Triggering validation by using events
Triggering validation programmatically
Validating required fields
General guidelines for validation
Working with validation errors
Working with validation events
Public Properties
| 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 | |
| listener : Object
Specifies the validation listener. | Validator | |
| maxLength : Object
Maximum length for a valid String. | StringValidator | ||
| minLength : Object
Minimum length for a valid String. | StringValidator | ||
| property : String
A String specifying the name of the property
of the source object that contains
the value to validate. | Validator | |
| 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 | |
| tooLongError : String
Error message when the String is longer
than the maxLength property. | StringValidator | ||
| tooShortError : String
Error message when the string is shorter
than the minLength property. | StringValidator | ||
| 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
Public Methods
| Method | Defined By | ||
|---|---|---|---|
Constructor. | StringValidator | ||
| 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 | |
|
Called automatically by the MXML compiler when the Validator
is created using an MXML tag. | Validator | |
|
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 | |
|
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 | |
|
Performs validation and optionally notifies
the listeners of the result. | Validator | |
| [static]
Invokes all the validators in the validators Array. | Validator | |
[static]
Convenience method for calling a validator. | StringValidator | ||
|
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 | |
Protected Methods
| Method | Defined By | ||
|---|---|---|---|
|
Sets up all of the listeners for the
valid and invalid
events dispatched from the validator. | Validator | |
[override]
Override of the base class doValidation() method
to validate a String. | StringValidator | ||
|
Returns the Object to validate. | Validator | |
|
Returns a ValidationResultEvent from the Array of error results. | Validator | |
|
Returns true if value is not null. | Validator | |
|
Disconnects all of the listeners for the
valid and invalid
events dispatched from the validator. | Validator | |
|
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 | |
Protected Constants
Property Detail
maxLength | property |
maxLength:Object| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Maximum length for a valid String. A value of NaN means this property is ignored.
The default value is NaN.
Implementation
public function get maxLength():Object public function set maxLength(value:Object):voidminLength | property |
minLength:Object| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Minimum length for a valid String. A value of NaN means this property is ignored.
The default value is NaN.
Implementation
public function get minLength():Object public function set minLength(value:Object):voidtooLongError | property |
tooLongError:String| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Error message when the String is longer
than the maxLength property.
The default value is "This string is longer than the maximum allowed length. This must be less than {0} characters long.".
Implementation
public function get tooLongError():String public function set tooLongError(value:String):voidtooShortError | property |
tooShortError:String| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Error message when the string is shorter
than the minLength property.
The default value is "This string is shorter than the minimum allowed length. This must be at least {0} characters long.".
Implementation
public function get tooShortError():String public function set tooShortError(value:String):voidConstructor Detail
StringValidator | () | Constructor |
public function StringValidator()| 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 String.
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.
|
Array — An Array of ValidationResult objects, with one ValidationResult
object for each field examined by the validator.
|
validateString | () | method |
public static function validateString(validator:StringValidator, value:Object, baseField:String = null):Array| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Convenience method for calling a validator. Each of the standard Flex validators has a similar convenience method.
Parameters
validator:StringValidator — The StringValidator instance.
| |
value:Object — A field to validate.
| |
baseField:String (default = null)value parameter.
For example, if the value parameter specifies
value.mystring, the baseField value
is "mystring".
|
Array — An Array of ValidationResult objects, with one
ValidationResult object for each field examined by the validator.
|
Related API Elements
Examples How to use this example
StringValidatorExample.mxml
<?xml version="1.0" encoding="utf-8"?>
<!-- Simple example to demonstrate StringValidator. -->
<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>
import mx.controls.Alert;
</fx:Script>
<fx:Declarations>
<mx:StringValidator source="{fname}" property="text"
tooShortError="This string is shorter than the minimum allowed length of 4. "
tooLongError="This string is longer than the maximum allowed length of 20."
minLength="4" maxLength="20"
trigger="{myButton}" triggerEvent="click"
valid="Alert.show('Validation Succeeded!');"
invalid="Alert.show('Validation Failed!');"/>
</fx:Declarations>
<s:Panel title="StringValidator Example"
width="75%" height="75%"
horizontalCenter="0" verticalCenter="0">
<mx:Form left="10" right="10" top="10" bottom="10">
<mx:FormItem label="Enter a name between 4 and 20 characters: ">
<s:TextInput id="fname" width="100%"/>
</mx:FormItem>
<mx:FormItem >
<s:Button id="myButton" label="Validate" />
</mx:FormItem>
</mx:Form>
</s:Panel>
</s:Application>
Thu Dec 6 2018, 01:12 PM -08:00