zend form validation - php

Question

I wonder how Zend_Form validates inputs, I mean how does it know which input fields to validate. I looked to php globals($_POST, $_GET) and I didn't see anything set as an identifier(for example ) in order to know how validate. Can anyone suggest me any guide for this stuff?

Answer 1

Well, the best option to find out is to look at the code of Zend_Form:
/**
* Validate the form
*
* #param array $data
* #return boolean
*/
public function isValid($data)
{
if (!is_array($data)) {
require_once 'Zend/Form/Exception.php';
throw new Zend_Form_Exception(__METHOD__ . ' expects an array');
}
$translator = $this->getTranslator();
$valid = true;
$eBelongTo = null;
if ($this->isArray()) {
$eBelongTo = $this->getElementsBelongTo();
$data = $this->_dissolveArrayValue($data, $eBelongTo);
}
$context = $data;
foreach ($this->getElements() as $key => $element) {
if (null !== $translator && $this->hasTranslator()
&& !$element->hasTranslator()) {
$element->setTranslator($translator);
}
$check = $data;
if (($belongsTo = $element->getBelongsTo()) !== $eBelongTo) {
$check = $this->_dissolveArrayValue($data, $belongsTo);
}
if (!isset($check[$key])) {
$valid = $element->isValid(null, $context) && $valid;
} else {
$valid = $element->isValid($check[$key], $context) && $valid;
$data = $this->_dissolveArrayUnsetKey($data, $belongsTo, $key);
}
}
foreach ($this->getSubForms() as $key => $form) {
if (null !== $translator && !$form->hasTranslator()) {
$form->setTranslator($translator);
}
if (isset($data[$key]) && !$form->isArray()) {
$valid = $form->isValid($data[$key]) && $valid;
} else {
$valid = $form->isValid($data) && $valid;
}
}
$this->_errorsExist = !$valid;
// If manually flagged as an error, return invalid status
if ($this->_errorsForced) {
return false;
}
return $valid;
}
which means in a nutshell, Zend_Form will iterate over all the configured elements in the form and compare them against the values in the array you passed to it. If there is a match, it will validate that individual value against the configured validators.

Answer 2

So, you create form in action and then check is there post|get data. You can check is_valid form right here. You need pass $_POST or $_GET data to isValid() function. Example:
if ($request->isPost() && $form->isValid($request->getPost())) {
isValid() is function Zend_Form class. Form runs all validations for each element (just if you dont set to stop in first validation fail) and then for subforms too.

Answer 3

Look at Zend_Form quickstart, it's a very bright example on how to start dealing with forms in Zend.
Validating a text input looks like this:
$username = new Zend_Form_Element_Text('username');
// Passing a Zend_Validate_* object:
$username->addValidator(new Zend_Validate_Alnum());
// Passing a validator name:
$username->addValidator('alnum');

Answer 4

Or you can use:
$username_stringlength_validate = new Zend_Validate_StringLength(6, 20);
$username = new Zend_Form_Element_Text('username');
$username->setLabel('Username: ')
->addFilters(array('StringTrim', 'HtmlEntities'))
->setAttrib('minlength', '6')
->setAttrib('class', 'required')
->removeDecorator('label')
->removeDecorator('HtmlTag')
->removeDecorator('DtDdWrapper')
->setDecorators(array(array('ViewHelper'), array('Errors')))
->addValidator($username_stringlength_validate);