RegExpValidator never matches - regex

Question

I've got a class that's meant to validate input fields to make sure the value is always a decimal. I've tested the regex here: http://livedocs.adobe.com/flex/3/html/help.html?content=validators_7.html, and it looks like it does the right thing, but in my app, I can't seem to get it to match to a number format.
Class Definition:
public class DecimalValidator {
//------------------------------- ATTRIBUTES
public var isDecimalValidator:RegExpValidator;
//------------------------------- CONSTRUCTORS
public function DecimalValidator() {
isDecimalValidator = new RegExpValidator();
isDecimalValidator.expression = "^-?(\d+\.\d*|\.\d+)$";
isDecimalValidator.flags = "g";
isDecimalValidator.required = true;
isDecimalValidator.property = "text";
isDecimalValidator.triggerEvent = FocusEvent.FOCUS_OUT;
isDecimalValidator.noMatchError = "Float Expected";
}
}
Setting the source here:
public function registerDecimalInputValidator(inputBox:TextInput, valArr:Array):void {
// Add Validators
var dValidator:DecimalValidator = new DecimalValidator();
dValidator.isDecimalValidator.source = inputBox;
dValidator.isDecimalValidator.trigger = inputBox;
inputBox.restrict = "[0-9].\\.\\-";
inputBox.maxChars = 10;
valArr.push(dValidator.isDecimalValidator);
}
And Calling it here:
registerDecimalInputValidator(textInput, validatorArr);
Where textInput is an input box created earlier.
Clearly I'm missing something simple yet important, but I'm not entirely sure what! Any help would be much appreciated.

Answer 1

I don't know ActionScript, but as far as I know it's an ECMAScript language, so I expect you need to escape the backslashes if you use a string to define a regex:
isDecimalValidator.expression = "^-?(\\d+\\.\\d*|\\.\\d+)$";

Answer 2

This strikes me as wrong; but I can't quite put my finger on it. For your DecimalValidator instead of composing a RegExpValidator; why not extend it?
public class DecimalValidator extend RegExpValidator{
//------------------------------- CONSTRUCTORS
public function DecimalValidator() {
super()
this.expression = "^-?(\d+\.\d*|\.\d+)$";
this.flags = "g";
this.required = true;
this.property = "text";
this.triggerEvent = FocusEvent.FOCUS_OUT;
this.noMatchError = "Float Expected";
}
}
How when is the registerdecimalInputValidator called? I have a slight worry about the Validator instance is a local variable to a method instead of 'global' property to the function.
protected var dValidator:DecimalValidator = new DecimalValidator();
public function registerDecimalInputValidator(inputBox:TextInput):void {
dValidator.isDecimalValidator.source = inputBox;
dValidator.isDecimalValidator.trigger = inputBox;
}
I'm not sure why you are setting restrictions on the TextInput in the registerDecimalInputValidator method; that should be done when you create the method (in createChildren() or possibly in response to public properties changing, in commitProperties . It is also not obvious to me what the validatorArr does. If you're expecting to access values inside the validatorArrray outside of the method; it would often be a common practice to return that value from the method. Without looking it up; I'm not sure if Arrays are passed by value or reference in Flex.