EXPLANATION:
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.
CODING:
<?xml version=”1.0″?>
<!– Simple example to demonstrate the RegExpValidator. –>
<mx:Application xmlns:mx=”http://www.adobe.com/2006/mxml”>
<mx: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=”";
}
}
]]>
</mx:Script>
<mx:RegExpValidator id=”regExpV”
source=”{regex_text}” property=”text”
flags=”g” expression=”{regex.text}”
valid=”handleResult(event)” invalid=”handleResult(event)”
trigger=”{myButton}” triggerEvent=”click”/>
<mx:Panel title=”RegExpValidator Example” width=”95%” height=”95%”
paddingTop=”5″ paddingLeft=”5″ paddingRight=”5″ paddingBottom=”5″>
<mx:Text width=”100%” text=”Instructions:”/>
<mx:Text width=”100%” text=”1. Enter text to search. By default, enter a string containing the letters ABC in sequence followed by any digit.”/>
<mx:Text width=”100%” text=”2. Enter the regular expression. By default, enter ABC\d.”/>
<mx:Text width=”100%” text=”3. Click the Button control to trigger the validation.”/>
<mx:Text 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: “>
<mx:TextInput id=”regex_text” text=”xxxxABC4xxx” width=”100%”/>
</mx:FormItem>
<mx:FormItem label=”Enter regular expression: “>
<mx:TextInput id=”regex” text=”ABC\d” width=”100%”/>
</mx:FormItem>
<mx:FormItem label=”Results: “>
<mx:TextInput id=”reResults” width=”100%”/>
</mx:FormItem>
<mx:FormItem >
<mx:Button id=”myButton” label=”Validate”/>
</mx:FormItem>
</mx:Form>
</mx:Panel>
</mx:Application>
