What is VOLT macro for rendering a <form> tag?

In Phalcon one can create a custom form extending Phalcon\Form\Form. This class has method called setAction, but I cannot find any info on how to automatically render a <form> tag with action that I specified.

My form is called RegisterForm, and I am passing it to VOLT view like this:

$this->view->registerForm = new RegisterForm(new UserModel()); 

In my VOLT template I can use the registerForm.render('username') macro to automatically render input field registered in my form.

Is there any macro that will create the following?

<form action="/register" method="post">

assuming that I've used:

$this->setAction($this->url->get('index/register')); 

in the form definition.

After another day of research, and chatting at Phalcon's Slack channel, I've came to realization that, there is no built-in way of doing what I intended.

Simplest solution is to create a BaseForm class that extends Phalcon\Forms\Form. Here is an example:

<?php

namespace MyNamespace\Common\Form;

use Phalcon\Forms\Form;

class BaseForm extends Form {
    /**
     * Creates <form> tag in VOLT view.
     */
    public function startForm($method = 'post') {
        return '<form action="'.$this->getAction().'" method="'.$method.'">';
    }

    /**
     * Creates </form> tag in VOLT view.
     */
    public function endForm() {
        return '</form>';
    }

    /**
     * Pushes all errors to flash container.
     */
    public function error($name) {
        if($this->hasMessagesFor($name)) {
            foreach($this->getMessagesFor($name) as $message) {
                $this->flash->error($message);
            }

            return true;
        }

        return false;
    }
}

With this, after extending a custom form definition, I'm able to use:

# IndexController.php
public function index() {
    $this->view->registerForm = new RegisterForm();
}

# index.volt
{{ registerForm.startForm() }}
{{ registerForm.endForm() }}
{{ registerForm.error('username') }}