<?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\Component\Templating\Helper;

/**

 * SlotsHelper manages template slots.

 *

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

 *

 * @api

 */

class SlotsHelper extends Helper

{

    protected $slots = array();

    protected $openSlots = array();

    /**

     * Starts a new slot.

     *

     * This method starts an output buffer that will be

     * closed when the stop() method is called.

     *

     * @param string $name  The slot name

     *

     * @throws \InvalidArgumentException if a slot with the same name is already started

     *

     * @api

     */

    public function start($name)

    {

        if (in_array($name, $this->openSlots)) {

            throw new \InvalidArgumentException(sprintf('A slot named "%s" is already started.', $name));

        }

        $this->openSlots[] = $name;

        $this->slots[$name] = '';

        ob_start();

        ob_implicit_flush(0);

    }

    /**

     * Stops a slot.

     *

     * @throws \LogicException if no slot has been started

     *

     * @api

     */

    public function stop()

    {

        if (!$this->openSlots) {

            throw new \LogicException('No slot started.');

        }

        $name = array_pop($this->openSlots);

        $this->slots[$name] = ob_get_clean();

    }

    /**

     * Returns true if the slot exists.

     *

     * @param string $name The slot name

     *

     * @api

     */

    public function has($name)

    {

        return isset($this->slots[$name]);

    }

    /**

     * Gets the slot value.

     *

     * @param string $name    The slot name

     * @param string $default The default slot content

     *

     * @return string The slot content

     *

     * @api

     */

    public function get($name, $default = false)

    {

        return isset($this->slots[$name]) ? $this->slots[$name] : $default;

    }

    /**

     * Sets a slot value.

     *

     * @param string $name    The slot name

     * @param string $content The slot content

     *

     * @api

     */

    public function set($name, $content)

    {

        $this->slots[$name] = $content;

    }

    /**

     * Outputs a slot.

     *

     * @param string $name    The slot name

     * @param string $default The default slot content

     *

     * @return Boolean true if the slot is defined or if a default content has been provided, false otherwise

     *

     * @api

     */

    public function output($name, $default = false)

    {

        if (!isset($this->slots[$name])) {

            if (false !== $default) {

                echo $default;

                return true;

            }

            return false;

        }

        echo $this->slots[$name];

        return true;

    }

    /**

     * Returns the canonical name of this helper.

     *

     * @return string The canonical name

     *

     * @api

     */

    public function getName()

    {

        return 'slots';

    }

}