Models

The model is the part of the application that manages the data. It is the data layer. In a MVC application, the model should be responsible for the following:

Managing the data
Ensuring that data is valid before it is saved
Communicating with the database The model should never contain any logic for the presentation layer.

The model should never contain any HTML code.

The Piko\ModelTrait can be used to represent a data structure (model’s attributes) that need to be validated and mass assigned. A typical usage is to represent form data inputs.

Model’s attributes are declared as public properties in the inherited class.

Model’s attributes can be mass assigned using bind method.

Model’s attributes can be exported as array using toArray method.

To check model validity, we can use the isValid public method. This method symply check if the errors model’s property is empty. The class using this trait has to implement the protected validate method to fill the errors model’s property in case of error.

Use case example of \Piko\ModelTrait to represent a contact form:

Module structure:

site
    controllers
        DefaultController.php
    models
        ContactForm.php
    views
        default
            contact.php

ContactForm.php:

<?php
namespace app\modules\site\models;

use Piko\ModelTrait;

class ContactForm
{
    use ModelTrait;

    public $email = '';
    public $subject = '';
    public $message = '';

    protected function validate(): void
    {
        if (!filter_var($this->email, FILTER_VALIDATE_EMAIL)) {
            $this->setError('email', 'Email is invalid');
        }

        if (empty($this->subject)) {
            $this->setError('subject', 'Subject is required');
        }

        if (empty($this->message)) {
            $this->setError('message', 'Message is required');
        }
    }
}

DefaultController.php:

namespace app\modules\site\controllers;

use app\modules\site\models\ContactForm;

class DefaultController extends \Piko\Controller
{
    public function contactAction()
    {
        $form = new ContactForm();

        if ($this->request->getMethod() == 'POST') {

            $post = $this->request->getParsedBody();
            $form->bind($post);

            if ($form->isValid()) {
                // Send an email, Save in database, etc.
            }
        }

        return $this->render('contact', [
            'form' => $form
        ]);
    }
}

contact.php:

<?php
/**
 * @var $this Piko\View
 * @var $form app\modules\site\models\ContactForm
 */

$errors = $form->getErrors();
?>

<?php if ($errors): ?>
<p><?= implode('<br>', $errors) ?></p>
<?php endif ?>

<form action="" method="post">
  <p>
    <input type="email"
           name="email"
           value="<?= $form->email ?>"
           placeholder="Email">
  </p>
  <p>
    <input type="text"
           name="subject"
           value="<?= $form->subject ?>"
           placeholder="Subject">
  </p>
  <p>
    <label for="message">Message</label><br>
    <textarea  name="message" id="message" rows="5">
    <?= $form->message ?>
    </textarea>
  </p>
  <p>
    <button type="submit" >Submit</button>
  </p>
</form>