The Bakery Everything CakePHP

This is an article ported from the wiki. The original author is evansagge.

Introduction

The built-in functions for validating model data are fine for simple validation techniques, but quite often you will find yourself needed to perform several validations on the same field.

The method of validation below will allow you to perform complex validation of your data with almost no extra work beyond describing the validation.

AppModel Additions

To begin with, the following code should be added to your AppModel.

Model Class:

Download code <?php 
// file: /app/app_model.php
define('VALID_WORD', '/^\\w+$/');
define('VALID_UNIQUE', 'isUnique');
define('VALID_LENGTH_WITHIN', 'isLengthWithin');
define('VALID_CONFIRMED', 'isConfirmed');
 
class AppModel extends Model {
 
  // If you need to disable validation for particular columns, you may populate this variable like so:
  // $this->User->disabledValidate = array('email', 'password'); // disables validation on email and password columns
  // $this->User->disabledValidate = array(
  //   'email',
  //   'password' => array('confirmed', 'required')
  // ); // disables validation on email column, and password['confirmed'] && password['required']
  var $disabledValidate;
  
  function loadValidation() {
    // placeholder for overloading
  }
     
  function invalidFields($data = array()) {
    $this->loadValidation();

    if (!$this->beforeValidate()) {
        return false;
    }

    if (is_array($this->disabledValidate)) {
      foreach($this->disabledValidate as $field => $params) {
        if (is_string($field) && is_array($params)) {
          foreach($params as $param) {
            if (is_string($param)) {
              $this->validate[$field][$param] = false;
            }
          }
        } else if (is_int($field) && is_string($params)) {
          $this->validate[$params] = false;
        }
      }
    }
    
    //debug($this->validate);
    
    if (!isset($this->validate) || !empty($this->validationErrors)) {
      if (!isset($this->validate)) {
        return true;
      } else {
        return $this->validationErrors;
      }
    }
 
    if (isset($this->data)) {
      $data = array_merge($data, $this->data);
    }
 
    $errors = array();
    $this->set($data);
 
    foreach ($data as $table => $field) {
      foreach ($this->validate as $field_name => $validators) {
        if ($validators) {      
          foreach($validators as $validator) {
            if (isset($validator['method'])) {
              if (method_exists($this, $validator['method'])) {
                $parameters = (isset($validator['parameters'])) ? $validator['parameters'] : array();
                $parameters['var'] = $field_name;
                if (isset($data[$table][$field_name]) &&
                  !call_user_func_array(array(&$this, $validator['method']),array($parameters))) {
                  if (!isset($errors[$field_name])) {
                    $errors[$field_name] = isset($validator['message']) ? $validator['message'] : 1;
                  }
                }
              } else {
                if (isset($data[$table][$field_name]) &&
                  !preg_match($validator['method'], $data[$table][$field_name])) {
                  if (!isset($errors[$field_name])) {
                    $errors[$field_name] = isset($validator['message']) ? $validator['message'] : 1;
                  }
                }
              }
            }
          }
        }
      }
    }
    $this->validationErrors = $errors;
    return $errors;
  }
  
  // validation methods
    
  function isUnique($params) {
    $val = $this->data[$this->name][$params['var']];
    $db = $this->name . '.' . $params['var'];
    $id = $this->name . '.id';
    if($this->id == null ) {
      return(!$this->hasAny(array($db => $val ) ));
    } else {
      return(!$this->hasAny(array($db => $val, $id => '!='.$this->data[$this->name]['id'] ) ) );
    }
  }
 
  function isLengthWithin($params) {
    $val = $this->data[$this->name][$params['var']];
    $length = strlen($val);
 
    if (array_key_exists('min', $params) && array_key_exists('max', $params)) {
      return $length >= $params['min'] && $length <= $params['max'];
    } else if (array_key_exists('min', $params)) {
      return $length >= $params['min'];
    } else if (array_key_exists('max', $params)) {
      return $length <= $params['max'];
    }
  }
 
  function isConfirmed($params) {
    $val = $this->data[$this->name][$params['var']];
    $val_confirmation = array_key_exists('confirm_var', $params) ?
      $this->data[$this->name][$params['confirm_var']] :
      $this->data[$this->name][$params['var'].'_confirmation'];
    return $val == $val_confirmation;
  }
}
?>

You will notice that all the validation routines are DEFINE()d before the class is declared. This helps keep the appearance of the validation system uniform and does not differentiate between regex and method calls in the constant names.

The loadValidation() method is declared as empty, as it will be overloaded by our individual model classes later. It will be called by the invalidFields() method.

If you need to disable validation on certain columns or column validation routines, you can populate the disabledValidate array on the controller before calling save().

Usage

An example of how to use these complex validation routines is shown below, using the example of a Users model. Simply create a nested array containing the validation methods (and their parameters) to apply multiple validators to each field. A message can be defined which may be displayed to the user on triggering the error.

Model Class:

Download code <?php 
class User extends AppModel {
  var $name = 'User';
  var $validate;
 
  function loadValidation(){
    $this->validate = array(
      'username' => array(
        'required' => array(
          'method' => VALID_NOT_EMPTY,
          'message' => 'You have not entered a username.',
        ),
        'word' => array(
          'method' => VALID_WORD,
          'message' => 'The username you entered contains invalid characters.'
        ),          
        'unique' => array(
          'method' => VALID_UNIQUE,
          'message' => 'The username you entered is already in use.'
        ),
        'length_within' => array(
          'method' => VALID_LENGTH_WITHIN,
          'message' => 'Username should be between 6 to 50 characters long.',
          'parameters' => array('min' => 6, 'max' => 50)
        ),   
      ),
      'email' => array(
        'required' => array(
          'method' => VALID_NOT_EMPTY,
          'message' => 'You have not entered an e-mail address.',
        ),
        'email' => array(
          'method' => VALID_EMAIL,
          'message' => 'The e-mail address you entered is not in proper format.'
        ),          
        'unique' => array(
          'method' => VALID_UNIQUE,
          'message' => 'The e-mail address you entered is already in use.'
        ),
        'confirmed' => array(
          'method' => VALID_CONFIRMED,
          'message' => 'The e-mail addresses you entered does not match its confirmation.'
        ),
      ),
      'password' => array(
        'required' => array(
          'method' => VALID_NOT_EMPTY,
          'message' => 'You have not entered a password.',
        ),
        'length_within' => array(
          'method' => VALID_LENGTH_WITHIN,
          'message' => 'Password should be between 8 to 50 characters long.',
          'parameters' => array('min' => 8, 'max' => 50)
        ),           
        'confirmed' => array(
          'method' => VALID_CONFIRMED,
          'message' => 'The password you entered does not match its confirmation.'
        ),
      ),               
    );
  }
}
?>
When using VALID_LENGTH_WITHIN, you can either specify min parameter (only validates minimum length requirement), max parameter (only validates maximum length requirement), or both.



When using these routines, there is no difference as far as the controller is concerned:

Controller Class:

Download code <?php 
class UsersController extends AppController {
  var $name = 'Users';
 
  var $helpers = array('Html', 'Error', 'Javascript', 'Ajax');
 
  function register() {
    if (!empty($this->data)) {
      if ($this->User->save($this->data)) {
        $this->flash('You have successfully registered your account.', '/users');
      }
    }
  }
}
?>

Displaying errors

The following error helper can be used from a view to display the error messages defined within the model.

Helper Class:

Download code <?php 
class ErrorHelper extends Helper {
 
  function messageFor($target) {
      list($model, $field) = explode('/', $target);
 
      if (isset($this->validationErrors[$model][$field])) {
          return '<span class="form_error_message">'.$this->validationErrors[$model][$field].'</span>';
      } else {
          return null;
      }
  }
  
  function allMessagesFor($model) {
    $html =& new HtmlHelper;
    
    if (isset($this->validationErrors[$model])) {
      $list = '';
      foreach (array_keys($this->validationErrors[$model]) as $field) {
        $list .= $html->contentTag('li', $this->validationErrors[$model][$field]);
      }
      return $html->contentTag('div', 
        $html->contentTag('h4', 'The following errors need to be corrected: ') . 
        $html->contentTag('ul', $list), array('class'=>'error_messages'));
    }
  }
}
?>

And finally, an example of the helper as used from the view:

View Template:

Download code
<?php echo $error->allMessagesFor('User'); // This line is for displaying the error messages from our form all at once. ?>
 
<form id="register" name="register" method="POST" action="<?php echo $html->url('/users/register')?>">
  <label>Username</label>
  <?php echo $html->input('User/username')?>
  <?php echo $error->messageFor('User/username')?>
  <br />
 
  <label>Email</label>
  <?php echo $html->input('User/email')?>
  <?php echo $error->messageFor('User/email')?>
  <br />
 
  <label>Confirm Email</label>
  <?php echo $html->input('User/email_confirmation')?>
  <?php echo $error->messageFor('User/email_confirmation')?>
  <br />
 
  <label>Password</label>
  <?php echo $html->password('User/password')?>
  <?php echo $error->messageFor('User/password')?>
  <br />
 
  <label>Confirm Password</label>
  <?php echo $html->password('User/password_confirmation')?>
  <?php echo $error->messageFor('User/password_confirmation')?>
  <br />
 
  <?php echo $html->submit('Register')?>
</form>


Note:

Don't forget that you can add your own validation routines by adding a regular expression/method to the AppController class.