Core Improvements: Next Round #79 #80

engine/Shortcode.php

@@ -0,0 +1,180 @@
+<?php defined('MONSTRA_ACCESS') or die('No direct script access.');
+
+/**
+ *	Monstra Shortcodes API
+ *
+ *  The Shortcode API s a simple regex based parser that allows you to replace simple bbcode-like tags
+ *  within a HTMLText or HTMLVarchar field when rendered into a content.
+ *
+ *  Examples of shortcode tags:
+ *
+ *     {shortcode}
+ *     {shortcode parameter="value"}
+ *     {shortcode parameter="value"}Enclosed Content{/shortcode}
+ *
+ *
+ *  Example of escaping shortcodes:
+ *
+ *     {{shortcode}}
+ *
+ *
+ *  @package Monstra
+ *  @subpackage Engine
+ *  @author Romanenko Sergey / Awilum
+ *  @copyright 2012 Romanenko Sergey / Awilum
+ *  @version $Id$
+ *  @since 1.0.0
+ *  @license http://opensource.org/licenses/gpl-license.php GNU Public License
+ *  Monstra is free software. This version may have been modified pursuant
+ *  to the GNU General Public License, and as distributed it includes or
+ *  is derivative of works licensed under the GNU General Public License or
+ *  other free or open source software licenses.
+ *  See COPYING.txt for copyright notices and details.
+ *  @filesource
+ */
+
+class Shortcode
+{
+    /**
+     * Shortcode tags array
+     *
+     * @var shortcode_tags
+     */
+    protected static $shortcode_tags = array();
+
+    /**
+     * Protected constructor since this is a static class.
+     *
+     * @access  protected
+     */
+    protected function __construct()
+    {
+        // Nothing here
+    }
+
+    /**
+     * Add new shortcode
+     *
+     *  <code>
+     *      function returnSiteUrl() {
+     *          return Option::get('siteurl');
+     *      }
+     *
+     *      // Add shortcode {siteurl}
+     *      Shortcode::add('siteurl', 'returnSiteUrl');
+     *  </code>
+     *
+     * @param string $shortcode         Shortcode tag to be searched in content.
+     * @param string $callback_function The callback function to replace the shortcode with.
+     */
+    public static function add($shortcode, $callback_function)
+    {
+        // Redefine vars
+        $shortcode = (string) $shortcode;
+
+        // Add new shortcode
+        if (is_callable($callback_function)) Shortcode::$shortcode_tags[$shortcode] = $callback_function;
+    }
+
+    /**
+     * Remove a specific registered shortcode.
+     *
+     *  <code>
+     *      Shortcode::delete('shortcode_name');
+     *  </code>
+     *
+     * @param string $shortcode Shortcode tag.
+     */
+    public static function delete($shortcode)
+    {
+        // Redefine vars
+        $shortcode = (string) $shortcode;
+
+        // Delete shortcode
+        if (Shortcode::exists($shortcode)) unset(Shortcode::$shortcode_tags[$shortcode]);
+    }
+
+    /**
+     * Remove all registered shortcodes.
+     *
+     *  <code>
+     *      Shortcode::clear();
+     *  </code>
+     *
+     */
+    public static function clear()
+    {
+        Shortcode::$shortcode_tags = array();
+    }
+
+    /**
+     * Check if a shortcode has been registered.
+     *
+     *  <code>
+     *      if (Shortcode::exists('shortcode_name')) {
+     *          // do something...
+     *      }
+     *  </code>
+     *
+     * @param string $shortcode Shortcode tag.
+     */
+    public static function exists($shortcode)
+    {
+        // Redefine vars
+        $shortcode = (string) $shortcode;
+
+        // Check shortcode
+        return array_key_exists($shortcode, Shortcode::$shortcode_tags);
+    }
+
+    /**
+     * Parse a string, and replace any registered shortcodes within it with the result of the mapped callback.
+     *
+     *  <code>
+     *      $content = Shortcode::parse($content);
+     *  </code>
+     *
+     * @param  string $content Content
+     * @return string
+     */
+    public static function parse($content)
+    {
+        if ( ! Shortcode::$shortcode_tags) return $content;
+
+        $shortcodes = implode('|', array_map('preg_quote', array_keys(Shortcode::$shortcode_tags)));
+        $pattern    = "/(.?)\{([$shortcodes]+)(.*?)(\/)?\}(?(4)|(?:(.+?)\{\/\s*\\2\s*\}))?(.?)/s";
+
+        return preg_replace_callback($pattern, 'Shortcode::_handle', $content);
+    }
+
+    /**
+     * _handle()
+     */
+    protected static function _handle($matches)
+    {
+        $prefix    = $matches[1];
+        $suffix    = $matches[6];
+        $shortcode = $matches[2];
+
+        // Allow for escaping shortcodes by enclosing them in {{shortcode}}
+        if ($prefix == '{' && $suffix == '}') {
+            return substr($matches[0], 1, -1);
+        }
+
+        $attributes = array(); // Parse attributes into into this array.
+
+        if (preg_match_all('/(\w+) *= *(?:([\'"])(.*?)\\2|([^ "\'>]+))/', $matches[3], $match, PREG_SET_ORDER)) {
+            foreach ($match as $attribute) {
+                if ( ! empty($attribute[4])) {
+                    $attributes[strtolower($attribute[1])] = $attribute[4];
+                } elseif ( ! empty($attribute[3])) {
+                    $attributes[strtolower($attribute[1])] = $attribute[3];
+                }
+            }
+        }
+
+        // Check if this shortcode realy exists then call user function else return empty string
+        return (isset(Shortcode::$shortcode_tags[$shortcode])) ? $prefix . call_user_func(Shortcode::$shortcode_tags[$shortcode], $attributes, $matches[5], $shortcode) . $suffix : '';
+    }
+
+}