The following example shows you how to use the StringUtil.trim() method in Flex to remove leading and trailing whitespace from form fields before validating user input.It automatically removes the whitespace when the focus is out from the form field.
<?xml version=”1.0″ encoding=”utf-8″?>
<mx:Application xmlns:mx=”http://www.adobe.com/2006/mxml” layout=”absolute”>
<mx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.controls.TextInput;
import mx.utils.StringUtil;
import mx.validators.Validator;
private function trimStr(evt:FocusEvent):void {
var ti:TextInput = TextInput(evt.currentTarget);
ti.text = StringUtil.trim(ti.text);
}
private function validateForm():void {
var errors:Array = Validator.validateAll(validatorArray);
if (errors.length) {
Alert.show("Form is somehow invalid.", "INVALID");
} else {
Alert.show("Form is valid.", "VALID");
}
}
]]>
</mx:Script>
<mx:Array id=”validatorArray”>
<mx:StringValidator id=”firstNameValidator”
source=”{firstName}”
property=”text”
required=”true” />
<mx:StringValidator id=”lastNameValidator”
source=”{lastName}”
property=”text”
required=”true” />
<mx:EmailValidator id=”emailValidator”
source=”{email}”
property=”text”
required=”true” />
</mx:Array>
<mx:Panel x=”10″ y=”10″ width=”416″ height=”291″ layout=”absolute”>
<mx:Form x=”20″ y=”31″>
<mx:FormItem label=”First name:” required=”true”>
<mx:TextInput id=”firstName” focusOut=”trimStr(event)” />
</mx:FormItem>
<mx:FormItem label=”Last name:” required=”true”>
<mx:TextInput id=”lastName” focusOut=”trimStr(event)” />
</mx:FormItem>
<mx:FormItem label=”Email:” required=”true”>
<mx:TextInput id=”email” focusOut=”trimStr(event)” />
</mx:FormItem>
<mx:FormItem>
<mx:Button label=”Submit” click=”validateForm()” />
</mx:FormItem>
</mx:Form>
</mx:Panel>
</mx:Application>
