DateValidator, Configuration error: Incorrect formatting string

Question

Hi guys,
I am struggling with a DateValidator issue, I hope someone can help me
Here is the parts of code needed to check what's wrong:
public const DATE_FORMAT:String = "DD/MMMM/YYYY";
<mx:DateFormatter id="dateFormatter" formatString="{DATE_FORMAT}" />
<mx:DateValidator
id="firstDateValidator" inputFormat="{DATE_FORMAT}" required="true"
source="{firstDate}" property="text" />
<mx:DateFiel id="firstDate" labelFunction="doLabel" />
private function doLabel(item:Date):String
     return dateFormatter.format(item);
I need to format and validate the following example: 13/January/2011
When I use DATE_FORMAT = "DD/MM/YYYY", I have no problem to format and validate the Datefield, I have 13/01/2011.
But when I use DATE_FORMAT = "DD/MMMM/YYYY", I have the following error message with the validator (the formatter is working well):
Configuration error: Incorrect formatting string.
Thank you very much for your help.

Answer 1

Standard Flex validator out of the box is very fragile when it comes to validate "non-standard" date formats. You should extend this DateValidator with your own version like I do, that re-implements "format" function call and rewrites private function "validateFormatString" from the the scratch.
Here is the my implementation of this function:
private static function validateFormatString(validator : DateRangeValidator,
                                                     separatorSign : String,
                                                     formatPartsArray : Array,
                                                     baseField : String) : ValidationResult {
            var formatPartsValidationObject : Object = {dayValid : false,
                monthValid : false,
                yearValid : false};
            var formatsLength : int = formatPartsArray.length;
            var mask:String;           
            for (var i : int  = 0; i < formatsLength; i++) {
                mask = formatPartsArray[i];               
                switch (mask) {
                    case "M" :
                    case "MM" :
                    case "MMM" :                       
                    case "MMMM" :
                        formatPartsValidationObject.monthValid = true;
                        break;
                    case "YY" :
                    case "YYYY" :
                        formatPartsValidationObject.yearValid = true;
                        break;                   
                    case "D" :
                    case "DD" :                   
                        formatPartsValidationObject.dayValid = true;                       
                        break;                       
            if (formatPartsValidationObject.monthValid &&
                formatPartsValidationObject.dayValid &&
                formatPartsValidationObject.yearValid) {
                return null; // Passes format validation
            } else {
                return new ValidationResult(
                    true, baseField, "format",
                    validator.formatError);
formatPartsArray is calculated as follows:  
var formatPartsArray : Array = inputFormat.split("/");