Propel ORM Version 1.6.4 -understanding validators - validation

Question

(reworded the question hours later to be more descriptive)
I need a little advice on understanding Propel setters/validators in a standalone (non-framework) development.
The documentation on validation states:
Validators help you to validate an input before persisting it to the database.
... and in validator messages we can provided coherent advice on where users can correct entries that don't pass Propel validation.
The sample usage of a validator reads:
$user = new User();
$user->setUsername("foo"); // only 3 in length, which is too short...
if ($objUser->validate()) {
...
The problem I have found with this is 'what if you cannot setXXX() in order to validate it?'
I have a column type DATE and I invite a visitor to enter a date in a web form. They mistype the date and submit 03/18/20q2
I would hope that one of my custom validators would be able to report a validator message and return the form once more to the user to be amended, however this occurs first:
Fatal error: Uncaught exception 'PropelException' with message 'Error parsing date/time value: '03/18/20q2' [wrapped: DateTime::__construct() [<a href='datetime.--construct'>datetime.--construct</a>]: Failed to parse time string (03/18/aaa) at position 5 (/):
In my tests I couldn't get any simple or CustomValidator to fire once I'd written (for example):
$event= new Event();
$event->setDateStart($form_value_for_date); // where values is "03/18/20q2"
I understand why this is so - it would not make sense to be able to create and try to manipulate a new object if you cannot rely on its fields, even before you save it.
The dilemma this gives me is:
If a fatal error can result from invalid entry preventing Propel validation from handling it for me (and therefore the user) and sending back a useful message, should I bother with Propel validation as well as my own security/courtesy validation ?
I cannot find any mention in the docs of what happens if you give Propel - for whatever reason - a value it doesn't anticipate for the field, or how to handle it.
I do hope this makes sense and that someone can point me at a method that will mean I only need to validate input in one place.

Answer 1

I've hacked together a rough ready solution that will allow me to:
Pre-validate a field against a CustomValidator without setting it in the new object
Retrieve the validator's message for return to the user
I take the form input, sanitise it of course, and then create an object:
$event = new Event();
With my user form in mind, I then pre-check the field I know will fatally fall over if the content's bad, and only set the field in my new object if it would validate:
if ($check = $event->flightCheckFail('StartingDate','DateValidator',$sanitisedFormVal))
echo $check;
else
$event->setStartingDate($sanitisedFormVal);
Method flightCheckFail() will return false if the data from the form would validate against the field, it returns the validator's error message if it would fail.
The method's added to my Event class as follows. Its arguments are the field name, the class of the CustomValidator (which simply runs an strtotime check), and the sanitised form value:
public function flightCheckFail($name,$validatorClass,$value) {
$colname = $this->getPeer()->getTableMap()->getColumnByPhpName($name)->getName();
$validators = $this->getPeer()->getTableMap()->getColumn($colname)->getValidators();
foreach($validators as $validatorMap)
if ($validatorMap->getClass() == $validatorClass) {
$validator = BasePeer::getValidator($validatorMap->getClass());
if ( $validator->isValid($validatorMap, $value) === false)
$failureMessage = $validatorMap->getMessage();
} // if $validatorMap->getClass() == $validatorClass
if($failureMessage)
return $failureMessage;
else
return false;
}
I should be able to use this to work around handling dates in forms, but I'll need to check what other types in Propel might require this sort of handling.
I can stop the form handling wherever this reports a validator error message and send it back. When the user enters valid data, Propel (and normal Propel Validation) gets to continue as normal.
If anyone can improve on this I'd love to see your results.

Answer 2

You could also use a MatchValidator, with a date RegExp, no need for extra functions