I recently started porting some traditional html based forms over to an API... I copied over my Form classes and started converting them into Validation classes since I didnt need a lot of the Form functionality any longer... But i encountered a problem and some unexpected behavior. Traditionally when validating through a Form for an entity that already exists, I use the constructor like so:

$form = new UserForm($_POST, $existingUser);

This allows me to do some conditional checks in the forms initialize() method. IE:

if ($this->getEntity()){
    // do something different

The Validation class doesnt have an entity argument in its constructor... It does however have an entity argument in its validate() method. So I tried this:

$userValidation = new UserValidation();
$messages = $userValidation->validate($_POST, $existingUser);

I THOUGHT this was working, as i had access to $this->getEntity() in my initialize() method. However it seems the validation isnt working as expected. The validators (such as EmailValidator, etc...) are validating against the entities properties, not $_POST. The source code in validation.zep indeed shows thats whats going on. My question is why? Whats the use case for using the validation class with an entity? Should I just stick to Forms or am I doing something wrong?

The above code examples are contrived.