apps_controllers_PostsController.php

<?php

use Phalcon\Forms\Elements\Text as TextElement;
use Phalcon\Forms\Elements\TextArea as TextAreaElement;

use Phalcon\Validation\StringLength;
use Phalcon\Validation\PresenceOf;

class PostsController extends \Phalcon\Mvc\Controller
{
    protected function getForm($post)
    {
      
      $title = new TextElement('title');
      
      $title
        ->addValidation(new StringLength([
          'minimum' => 5,
          'message' => 'The title is too short'
        ])        
        ->addValidation(new PresenceOf([          
          'message' => 'The title is required'
        ]);        
        
      $content = new TextAreaElement('content');  
        
      $content
        ->addValidation(new StringLength([
          'minimum' => 5,
          'message' => 'The content is too short'
        ]);
      
      return $this->forms->create($post)        
        ->add($title)
        ->add($content);
     }

    public function editAction($id)
    {        
      $post = Posts::findFirstById($id);
      $this->view->setVar("form", $this->getForm($post)); 
    }
    
    public function saveAction()
    {
      $form = $this->getForm();
      if ($form->isValid($_POST)) {
        
        $post = new Posts();
        $post->save($_POST);
        
        $this->flash->success("Post was created successfully");
        
        return $this->response->redirect("posts/index");
      }
    }

}

apps_views_posts_edit.phtml

<?php echo $form->outputMessages() ?>

<form method="post" action="<?php echo $this->url->get("posts/save") ?>">

  <p>
  <label for="title">Title</label> <?php echo $form->render("title"); ?>
  </p>

  <p>
  <label for="content">Content</label> <?php echo $form->render("content"); ?>
  </p>

  <input type="submit" value="Save"/>

</form>