Zend Framework 2 - Output form element, objects as HTML fields

Question

Introduction

I'm working through a re-usable Admin module; responsible for handling Authentication, and ACL. This module comes with a base controller that any other module implemented can inherit. So this controller is the Cp\AdminController and isn't accessible, but inherited by all other controllers.

The problem

I have a default/home controller Cp\HomeController that has several actions; login, logout and forgotten/reset password. Currently i'm working on the Cp\HomeController::indexAction. Within this method I simply do the following:

// ... controller logic ...
public function indexAction()
{
    if ($this->getAuth()->hasIdentity()) {
        # XXX: This is the authorised view/dashboard.
    } else {
        # XXX: This is the unauthorised view; login page.

        $loginForm = new Form\Login();

        # XXX: validation, and login form handling here.

        return array(
            'form' => $loginForm
        );
    }
}
// ... controller logic ...

The issue here is, the Cp\HomeController by default, uses the ./module/Cp/view/cp/home/index.phtml template; and looks like:

<h1>Authorisation Required</h1>

<section id="admin-login">
    <?= $form ?>
</section>

I have extended Zend\Form with my own form class ./module/Cp/src/Cp/Form.php, this is then extended by any form classes. _Bare in mind, I will move this class into the App so that it's entirely decoupled and completely reusable.

<?php
// @file: ./module/Cp/src/Cp/Form.php

namespace Cp;

use Zend\Form\Form as ZendForm;
use Zend\Form\Fieldset;
use Zend\InputFilter\Input;
use Zend\InputFilter\InputFilter;
use Zend\View\Model\ViewModel;
use Zend\View\Renderer\PhpRenderer;
use Zend\View\Resolver;

class Form extends ZendForm
{
    /**
     * Define the form template path.
     * @var String
     */

    protected $__templatePath;

    /**
     * Define the view variables.
     * @var Array
     */

    protected $__viewVariables = array();

    /**
     * Set the view variable.
     * @param String $key The index for the variable.
     * @param Mixed $value The value for the view variable.
     * @return Cp\Form
     */

    public function set($key, $value)
    {
        $this->__viewVariables[$key] = $value;
        return $this;
    }

    /**
     * Set the template path.
     * @param String $path The path for the template file.
     * @return Cp\Form
     */

    public function setTemplatePath($path)
    {
        $this->__templatePath = $path;
        return $this;
    }

    /**
     * When the object is buffered in output, we're going to generate the view
     * and render it.
     * @return String
     */

    public function __toString()
    {
        // Define our template file as form for resolver to map.
        $map = new Resolver\TemplateMapResolver(array(
            'form' => $this->__templatePath
        ));

        // Define the render instance responsible for rendering the form.
        $renderer = new PhpRenderer();
        $renderer->setResolver(new Resolver\TemplateMapResolver($map));

        // The form view model will generate the form; parsing the vars to it.
        $view = new ViewModel();
        $view->setVariable('form', $this);
        $view->setTemplate('form');

        foreach ($this->__viewVariables as $key => $value) {
            if (! property_exists($view, $key)) {
                $view->setVariable($key, $value);
            }
        }

        return $renderer->render($view);
    }
}

I inherit this form class in order to create my Login form, a standard e-mail address and password field, something which can be re-used anywhere authentication may occur.

<?php

namespace Cp\Form;

use Zend\Form\Element;

class Login extends \Cp\Form
{
    public function __construct($name = 'Login', $action)
    {
        // Parse the form name to our parent constructor.
        parent::__construct($name);

        // Override default template, defining our form view.
        $this->setTemplatePath(MODULE_DIR . 'Cp/view/cp/form/login.phtml');

        // Create our form elements, and validation requirements.
        $email = new Element\Email('email');
        $email->setLabel('E-mail Address');

        $password = new Element\Password('password');
        $password->setLabel('Password');

        $submit = new Element\Submit('login');

        $this->setAttribute('action', $action)
            ->setAttribute('method', 'post')
            ->setAttribute('autocomplete', 'autocomplete')
            ->add($email)
            ->add($password)
            ->add($submit);
    }
}

Which the inherited __toString method will take the defined form view, and render it. This is where my problem is, and my question occurs. Within the view (see below) I am trying to create the form, by using the framework, without hard-coding the HTML elements. Since the Cp\Form\Login class could be extended and modified, with a different field, or additional fields, optional or mandatory, or conditionally either.

Is there a way to quickly, get Zend to generate the following HTML? Without using partial views or physically writing <input type="<?= ... ?>" name="<?= ... ?>" />. This is because the attributes can be defined or overwritten inside the controllers, thus, the attributes are unknown at this point; and should be open to flexibility.

<section class="authentication-form">
    <h2>Authentication Required</h2>

    <!-- How-to:  Generate the <form> tag and all it's attributes. -->
    <?= $form->openTag() ?>

    <? if ($ipAllowed): ?>
        <p>Please choose an account to log in through.</p>

        <fieldset>
            <?= $form->get('email') ?>
        </fieldset>
    <? else: ?>
        <p>Please log in using your e-mail address and password.</p>

        <fieldset>
            <?= $form->get('email') ?>
            <?= $form->get('password') ?>
        </fieldset>
    <? endif ?>

    <div class="action">
        <!-- How-To:  Generate the <input type="submit" name="" ... attributes ... />
        <?= $form->get('login') ?>
    </div>

    <!-- How-To: Generate the form close tag.
    <?= $form->closeTag() ?>
</section>

Hopefully this is more clearer, than previously.

Answer 1

I'm unsure what your actual question is. Could you specify it explicitly please?

Zend\Form is designed so that it doesn't render itself, but is rendered by view helpers:

<?php
echo $this->form()->openTag($this->form);
echo $this->formCollection($this->form);
echo $this->form()->closeTag($this->form);

You could of course write a view helper that does this for you.

Alternatively, you could write a view helper that takes a list of elements to render and write a view helper that does something like this:

<?php
namespace MyModule\View\Helper;

use Zend\View\Helper\AbstractHelper;


class RenderForm extends AbstractHelper
{
    public function __invoke($fieldsToRender, $form)
    {
        $html = $this->view->form()->openTag($form) . PHP_EOL;

        foreach ($fieldsToRender as $fieldName) {
            $element = $form->get($fieldName);
            $html .= $this->view->formRow($element) . PHP_EOL;
        }

        $html .= $this->view->form()->closeTag($form) . PHP_EOL;

        return $html;
    }
}

Then all you need in your view script is to call renderForm().