ORM models are tightly integrated with the Validation library and the module comes with a very flexible ORM_Validation_Exception that helps you quickly handle validation errors from basic CRUD operations.
Validation rules are defined in the ORM::rules() method. This method returns the array of rules to be added to the Validation object like so:
public function rules()
{
return array(
'username' => array(
// Uses Valid::not_empty($value);
array('not_empty'),
// Calls Some_Class::some_method('param1', 'param2');
array('Some_Class::some_method', array('param1', 'param2')),
// Calls A_Class::a_method($value);
array(array('A_Class', 'a_method')),
// Calls the lambda function and passes the field value and the validation object
array(function($value, Validation $object)
{
$object->error('some_field', 'some_error');
}, array(':value', ':validation')),
),
);
}
ORM will automatically bind the following values with Validation::bind():
All models automatically validate their own data when ORM::save(), ORM::update(), or ORM::create() is called. Because of this, you should always expect these methods to throw an ORM_Validation_Exception when the model's data is invalid.
public function action_create()
{
try
{
$user = ORM::factory('User');
$user->username = 'invalid username';
$user->save();
}
catch (ORM_Validation_Exception $e)
{
$errors = $e->errors();
}
}
The ORM_Validation_Exception will give you access to the validation errors that were encountered while trying to save a model's information. The ORM_Validation_Exception::errors() method works very similarly to Validation::errors(). Not passing a first parameter will return the name of the rules that failed. But unlike Validate::errors(), the first parameter of ORM_Validation_Exception::errors() is a directory path. The model's ORM::$_object_name will be appended to the directory in order to form the message file for Validation::errors() to use. The second parameter is identical to that of Validation::errors().
In the below example, the error messages will be defined in application/messages/models/user.php
public function action_create()
{
try
{
$user = ORM::factory('User');
$user->username = 'invalid username';
$user->save();
}
catch (ORM_Validation_Exception $e)
{
$errors = $e->errors('models');
}
}
Certain forms contain information that should not be validated by the model, but by the controller. Information such as a CSRF token, password verification, or a CAPTCHA should never be validated by a model. However, validating information in multiple places and combining the errors to provide the user with a good experience is often quite tedius. For this reason, the ORM_Validation_Exception is built to handle multiple Validation objects and namespaces the array of errors automatically for you. ORM::save(), ORM::update(), and ORM::create() all take an optional first parameter which is a Validation object to validate along with the model.
public function action_create()
{
try
{
$user = ORM::factory('User');
$user->username = $_POST['username'];
$user->password = $_POST['password'];
$extra_rules = Validation::factory($_POST)
->rule('password_confirm', 'matches', array(
':validation', ':field', 'password'
));
// Pass the extra rules to be validated with the model
$user->save($extra_rules);
}
catch (ORM_Validation_Exception $e)
{
$errors = $e->errors('models');
}
}
Because the validation object was passed as a parameter to the model, any errors found in that check will be namespaced into a sub-array called _external. The array of errors would look something like this:
array(
'username' => 'This field cannot be empty.',
'_external' => array(
'password_confirm' => 'The values you entered in the password fields did not match.',
),
);
This ensures that errors from multiple validation objects and models will never overwrite each other.
The power of the ORM_Validation_Exception can be leveraged in many different ways to merge errors from related models. Take a look at the list of Examples for some great use cases.