Validation

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.

Defining Rules

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')),
        ),
    );
}

Bound Values

ORM will automatically bind the following values with Validation::bind():

  • :field - The name of the field the rule is being applied to.
  • :value - The value of the field the rule is being applied to.
  • :model - The instance of the model that is being validated.

Automatic Validation

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();
    }
}

Handling Validation Exceptions

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');
    }
}

External Validation

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.