Creating a Zend_Validate object from an array - zend-framework

Question

I have this in a Zend_Form's init method:
$username_validators = array(
'Alpha',
array('StringLength', false, array(3, 20)),
);
$some_form->addElement('text', 'username', array(
'filters' => array('StringTrim', 'StringToLower'),
'validators' => $username_validators,
'required' => true,
'label' => 'Username:',
));
Is it possible to create a Zend_Validate object that loads the same validators array that I'm passing addElement? It would be something like:
$v = new Zend_Validate();
//this is the part I'm unsure. Zend_Validate doesn't have an addValidators method.
$v->addValidators($username_validators);
echo $v->isValid('testuser1');

Answer 1

Sure you can add a collection of validators from a member variable, as long as they don't require any dynamic options that need to be specified at instantiation.
Edit
It appears to me that, out of the box, you cannot do something similar. Zend_Form has a plugin loader/registry that enables you to use "short forms" for validators. The plugin loader is configured with paths and class prefixes that allow it to actually create true validator instances from the short forms and any provided validator options.
In contrast, the code of Zend_Validate::addValidator() appears to actually require an actual validator instance.
But it looks like you could kind of piggyback on this form/element registry as follows: create a form element, assign short form validators to the element, call getValidators() on the element (Zend_Form_Element::getValidators() seems to convert each short form validator into a real instance), and then feed these validators one at a time into Zend_Validate. Seems to be a long way around, but it should work.

Answer 2

Yes, you can do what you want as long as $username_validators has been declared and is accessible in the scope of the function / class. If you are using a class, you will declare a private variable:
private $userVariables;
Then in the constructor populate it:
public function __construct()
{
$this->userVariables = array(
//validator options here
);
}
You can now assign this single validator as many times as you like by calling $this->userVariables:
$v = new Zend_Validate();
$v->addValidators($this->userVariables); //this is the part I'm unsure
echo $v->isValid('testuser1');