如何将数据从模型传递到视图（或控制器）

Question

The question is simple: How can i pass data from model to view(or back to the controller) to display errors like "your password is too short"

Here is the controller

class UsersController extends Controller {

    private $username;
    private $password;

    function register()
    {
        if($_POST)
        {
            $this->User->username = $_POST['username'];
            $this->User->password = $_POST['password'];
            $this->User->register();
        }
    }



}

the model

class User extends Model {

    public $username;
    public $password;

    function register()
    {
        $username = $this->username;
        $password = $this->password;

        if (!empty($username) && !empty($password))
        {
            // registration process
        }
        else
        {
            // "you must provide a username and password" or something like that
        }
    }

Answer 1

Just have your register function in your model return "PASSWORD"; to the controller and have your controller take the return from the model and return it to the view. Let the view interpret what the error output for "PASSWORD" is.

Example:

the controller

class UsersController extends Controller {

    private $username;
    private $password;

    function register()
    {
        if($_POST)
        {
            $this->User->username = $_POST['username'];
            $this->User->password = $_POST['password'];
            return $this->User->register();
        }
    }
}

the model

class User extends Model {

    public $username;
    public $password;

    function register()
    {
        $username = $this->username;
        $password = $this->password;

        if (!empty($username) && !empty($password))
        {
            // ...
            return "SUCCESS";
        }
        else
        {
            return "PASSWORD";
        }
    }
}

the view

$responses = array("SUCCESS" => "Registered Successfully!", "PASSWORD" => "You must provide a username and password!");

$result = $this->UsersController->register();
echo $responses[$result];

Answer 2

Simply have your model methods to return a value, or throw exceptions, like any normal method. Then handle it in the controller. The view shouldn't touch the data directly from the model, that's the controller's job.

Answer 3

public function addAction()
{
    $form = $this->_getForm();
    $this->view->form = $form;
    $this->render('add', null, true);
}

public function editAction()
{
    $id = $this->getRequest()->getParam(0);
    $Model = DI::get('yourclass_Model');
    $form = $this->_getForm();
    $data = $Model->getData();
    $form->populate($data);
    $this->view->flashMessages = $this->_helper->FlashMessenger->getMessages();
    $this->view->form = $form;
    $this->render('add', null, true);
}

public function saveAction()
{
    $form = $this->_getForm();
    $Model = DI::get('yourclass_Model');
    try{
    $saved = $Model->saveForm($form, $_POST);
    } catch (Exception $e) {
       echo "<pre>";
       print_r($e);
       exit;
    }
    if($saved)
    {
        $this->_helper->FlashMessenger('Record Saved!');
        $this->_redirect("edit".$form->id->getValue(), array('exit'=>true));
    } 
    $this->view->errorMessage = 'There were some errors';
    $this->view->form = $form;
    $this->render('add', null, true);
}

Answer 4

Create a class which implements Singleton pattern and ArrayAccess interface. Or create something similar with dependency injection.

The ultimate solution would be if you create some validation architecture. (The model validates its self and it's error state is available in the views.)