<?php



/*

 * This file is part of the Symfony package.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */



namespace Symfony\Bridge\Twig\Extension;



use Symfony\Bridge\Twig\TokenParser\FormThemeTokenParser;

use Symfony\Component\Form\FormView;

use Symfony\Component\Form\Exception\FormException;



/**

 * FormExtension extends Twig with form capabilities.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 * @author Bernhard Schussek <bernhard.schussek@symfony.com>

 */

class FormExtension extends \Twig_Extension

{

    protected $resources;

    protected $templates;

    protected $environment;

    protected $themes;

    protected $varStack;



    public function __construct(array $resources = array())

    {

        $this->themes = new \SplObjectStorage();

        $this->varStack = new \SplObjectStorage();

        $this->templates = new \SplObjectStorage();



        $this->resources = $resources;

    }



    /**

     * {@inheritdoc}

     */

    public function initRuntime(\Twig_Environment $environment)

    {

        $this->environment = $environment;

    }



    /**

     * Sets a theme for a given view.

     *

     * @param FormView $view      A FormView instance

     * @param array    $resources An array of resources

     */

    public function setTheme(FormView $view, array $resources)

    {

        $this->themes->attach($view, $resources);

        $this->templates->detach($view);

    }



    /**

     * Returns the token parser instance to add to the existing list.

     *

     * @return array An array of Twig_TokenParser instances

     */

    public function getTokenParsers()

    {

        return array(

            // {% form_theme form "SomeBungle::widgets.twig" %}

            new FormThemeTokenParser(),

        );

    }



    public function getFunctions()

    {

        return array(

            'form_enctype' => new \Twig_Function_Method($this, 'renderEnctype', array('is_safe' => array('html'))),

            'form_widget'  => new \Twig_Function_Method($this, 'renderWidget', array('is_safe' => array('html'))),

            'form_errors'  => new \Twig_Function_Method($this, 'renderErrors', array('is_safe' => array('html'))),

            'form_label'   => new \Twig_Function_Method($this, 'renderLabel', array('is_safe' => array('html'))),

            'form_row'     => new \Twig_Function_Method($this, 'renderRow', array('is_safe' => array('html'))),

            'form_rest'    => new \Twig_Function_Method($this, 'renderRest', array('is_safe' => array('html'))),

        );

    }



    /**

     * Renders the HTML enctype in the form tag, if necessary

     *

     * Example usage in Twig templates:

     *

     *     <form action="..." method="post" {{ form_enctype(form) }}>

     *

     * @param FormView $view  The view for which to render the encoding type

     */

    public function renderEnctype(FormView $view)

    {

        return $this->render($view, 'enctype');

    }



    /**

     * Renders a row for the view.

     *

     * @param FormView $view      The view to render as a row

     * @param array    $variables An array of variables

     */

    public function renderRow(FormView $view, array $variables = array())

    {

        return $this->render($view, 'row', $variables);

    }



    public function renderRest(FormView $view, array $variables = array())

    {

        return $this->render($view, 'rest', $variables);

    }



    /**

     * Renders the HTML for a given view

     *

     * Example usage in Twig:

     *

     *     {{ form_widget(view) }}

     *

     * You can pass attributes element during the call:

     *

     *     {{ form_widget(view, {'class': 'foo'}) }}

     *

     * Some fields also accept additional variables as parameters:

     *

     *     {{ form_widget(view, {}, {'separator': '+++++'}) }}

     *

     * @param FormView        $view       The view to render

     * @param array           $variables Additional variables passed to the template

     */

    public function renderWidget(FormView $view, array $variables = array())

    {

        return $this->render($view, 'widget', $variables);

    }



    /**

     * Renders the errors of the given view

     *

     * @param FormView $view The view to render the errors for

     */

    public function renderErrors(FormView $view)

    {

        return $this->render($view, 'errors');

    }



    /**

     * Renders the label of the given view

     *

     * @param FormView $view  The view to render the label for

     * @param string   $label Label name

     */

    public function renderLabel(FormView $view, $label = null)

    {

        return $this->render($view, 'label', null === $label ? array() : array('label' => $label));

    }



    protected function render(FormView $view, $section, array $variables = array())

    {

        $templates = $this->getTemplates($view);

        $blocks = $view->get('types');

        array_unshift($blocks, '_'.$view->get('id'));



        foreach ($blocks as &$block) {

            $block = $block.'_'.$section;



            if (isset($templates[$block])) {

                if ('widget' === $section || 'row' === $section) {

                    $view->setRendered();

                }



                $this->varStack[$view] = array_replace(

                    $view->all(),

                    isset($this->varStack[$view]) ? $this->varStack[$view] : array(),

                    $variables

                );



                $html = $templates[$block]->renderBlock($block, $this->varStack[$view]);



                return $html;

            }

        }



        throw new FormException(sprintf('Unable to render form as none of the following blocks exist: "%s".', implode('", "', $blocks)));

    }



    /**

     * Returns the templates used by the view.

     *

     * templates are looked for in the following resources:

     *   * resources from the themes (and its parents)

     *   * default resources

     *

     * @param FormView $view The view

     *

     * @return array An array of Twig_TemplateInterface instances

     */

    protected function getTemplates(FormView $view)

    {

        if (!$this->templates->contains($view)) {

            // defaults

            $all = $this->resources;



            // themes

            $parent = $view;

            do {

                if (isset($this->themes[$parent])) {

                    $all = array_merge($all, $this->themes[$parent]);

                }

            } while ($parent = $parent->getParent());



            $templates = array();

            foreach ($all as $resource) {

                if (!$resource instanceof \Twig_Template) {

                    $resource = $this->environment->loadTemplate($resource);

                }



                $blocks = array();

                foreach ($this->getBlockNames($resource) as $name) {

                    $blocks[$name] = $resource;

                }



                $templates = array_replace($templates, $blocks);

            }



            $this->templates->attach($view, $templates);

        } else {

            $templates = $this->templates[$view];

        }



        return $templates;

    }



    protected function getBlockNames($resource)

    {

        $names = $resource->getBlockNames();

        $parent = $resource;

        while (false !== $parent = $parent->getParent(array())) {

            $names = array_merge($names, $parent->getBlockNames());

        }



        return array_unique($names);

    }



    /**

     * Returns the name of the extension.

     *

     * @return string The extension name

     */

    public function getName()

    {

        return 'form';

    }

}