Apache Flex 4.16.1 API Reference | All Packages | All Classes | Index | Frames No Frames |
StringValidator

Package | mx.validators
Class | public class StringValidator
Inheritance | StringValidator Validator flash.events.EventDispatcher

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

The StringValidator class validates that the length of a String is within a specified range.

MXML Syntax Show MXML Syntax
Hide MXML Syntax

The `<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."
      />

View the examples

Public Properties
Hide Inherited Public Properties
Show Inherited Public Properties

| Property | Defined By
--- | --- | ---
|  | 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 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
Hide Inherited Protected Properties
Show Inherited Protected Properties

| 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
Hide Inherited Public Methods
Show Inherited Public Methods

| Method | Defined By
--- | --- | ---
|  | StringValidator() Constructor. | StringValidator
|  | initialized(document:Object, id:String):void Called automatically by the MXML compiler when the Validator is created using an MXML tag. | Validator
|  | 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
|  | validateString(validator:StringValidator, value:Object, baseField:String = null):Array [static] Convenience method for calling a validator. | StringValidator

Protected Methods
Show Inherited Protected Methods
Show Inherited Protected Methods

| 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 String. | StringValidator
|  | 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
Hide Inherited Events
Show Inherited Events

| Event | Summary | Defined By
--- | --- | --- | ---
|  | invalid | Dispatched when validation fails. | Validator
|  | valid | Dispatched when validation succeeds. | Validator

Protected Constants
Hide Inherited Protected Constants
Show Inherited Protected Constants

| 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

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):void`

minLength | 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):void`

tooLongError | 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):void`

tooShortError | 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):void`
Constructor 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.

Returns

| `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`)`` — Text representation of the subfield specified in the `value` parameter. For example, if the `value` parameter specifies value.mystring, the `baseField` value is `"mystring"`.

Returns

| `Array` — An Array of ValidationResult objects, with one ValidationResult object for each field examined by the validator.

See also

mx.validators.ValidationResult
Examples
StringValidatorExample.mxml

    <?xml version="1.0" encoding="utf-8"?>
    <!--

      Licensed to the Apache Software Foundation (ASF) under one or more
      contributor license agreements.  See the NOTICE file distributed with
      this work for additional information regarding copyright ownership.
      The ASF licenses this file to You under the Apache License, Version 2.0
      (the "License"); you may not use this file except in compliance with
      the License.  You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.

    -->
    <!-- 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>

Wed Nov 15 2017, 09:50 AM +01:00