<?php

/**

 * WordPress API for creating bbcode like tags or what WordPress calls

 * "shortcodes." The tag and attribute parsing or regular expression code is

 * based on the Textpattern tag parser.

 *

 * A few examples are below:

 *

 * [shortcode /]

 * [shortcode foo="bar" baz="bing" /]

 * [shortcode foo="bar"]content[/shortcode]

 *

 * Shortcode tags support attributes and enclosed content, but does not entirely

 * support inline shortcodes in other shortcodes. You will have to call the

 * shortcode parser in your function to account for that.

 *

 * {@internal

 * Please be aware that the above note was made during the beta of WordPress 2.6

 * and in the future may not be accurate. Please update the note when it is no

 * longer the case.}}

 *

 * To apply shortcode tags to content:

 *

 * <code>

 * $out = do_shortcode($content);

 * </code>

 *

 * @link http://codex.wordpress.org/Shortcode_API

 *

 * @package WordPress

 * @subpackage Shortcodes

 * @since 2.5

 */

/**

 * Container for storing shortcode tags and their hook to call for the shortcode

 *

 * @since 2.5

 * @name $shortcode_tags

 * @var array

 * @global array $shortcode_tags

 */

$shortcode_tags = array();

/**

 * Add hook for shortcode tag.

 *

 * There can only be one hook for each shortcode. Which means that if another

 * plugin has a similar shortcode, it will override yours or yours will override

 * theirs depending on which order the plugins are included and/or ran.

 *

 * Simplest example of a shortcode tag using the API:

 *

 * <code>

 * // [footag foo="bar"]

 * function footag_func($atts) {

 * 	return "foo = {$atts[foo]}";

 * }

 * add_shortcode('footag', 'footag_func');

 * </code>

 *

 * Example with nice attribute defaults:

 *

 * <code>

 * // [bartag foo="bar"]

 * function bartag_func($atts) {

 * 	extract(shortcode_atts(array(

 * 		'foo' => 'no foo',

 * 		'baz' => 'default baz',

 * 	), $atts));

 *

 * 	return "foo = {$foo}";

 * }

 * add_shortcode('bartag', 'bartag_func');

 * </code>

 *

 * Example with enclosed content:

 *

 * <code>

 * // [baztag]content[/baztag]

 * function baztag_func($atts, $content='') {

 * 	return "content = $content";

 * }

 * add_shortcode('baztag', 'baztag_func');

 * </code>

 *

 * @since 2.5

 * @uses $shortcode_tags

 *

 * @param string $tag Shortcode tag to be searched in post content.

 * @param callable $func Hook to run when shortcode is found.

 */

function add_shortcode($tag, $func) {

	global $shortcode_tags;

	if ( is_callable($func) )

		$shortcode_tags[$tag] = $func;

}

/**

 * Removes hook for shortcode.

 *

 * @since 2.5

 * @uses $shortcode_tags

 *

 * @param string $tag shortcode tag to remove hook for.

 */

function remove_shortcode($tag) {

	global $shortcode_tags;

	unset($shortcode_tags[$tag]);

}

/**

 * Clear all shortcodes.

 *

 * This function is simple, it clears all of the shortcode tags by replacing the

 * shortcodes global by a empty array. This is actually a very efficient method

 * for removing all shortcodes.

 *

 * @since 2.5

 * @uses $shortcode_tags

 */

function remove_all_shortcodes() {

	global $shortcode_tags;

	$shortcode_tags = array();

}

/**

 * Search content for shortcodes and filter shortcodes through their hooks.

 *

 * If there are no shortcode tags defined, then the content will be returned

 * without any filtering. This might cause issues when plugins are disabled but

 * the shortcode will still show up in the post or content.

 *

 * @since 2.5

 * @uses $shortcode_tags

 * @uses get_shortcode_regex() Gets the search pattern for searching shortcodes.

 *

 * @param string $content Content to search for shortcodes

 * @return string Content with shortcodes filtered out.

 */

function do_shortcode($content) {

	global $shortcode_tags;

	if (empty($shortcode_tags) || !is_array($shortcode_tags))

		return $content;

	$pattern = get_shortcode_regex();

	return preg_replace_callback('/'.$pattern.'/s', 'do_shortcode_tag', $content);

}

/**

 * Retrieve the shortcode regular expression for searching.

 *

 * The regular expression combines the shortcode tags in the regular expression

 * in a regex class.

 *

 * The regular expresion contains 6 different sub matches to help with parsing.

 *

 * 1/6 - An extra [ or ] to allow for escaping shortcodes with double [[]]

 * 2 - The shortcode name

 * 3 - The shortcode argument list

 * 4 - The self closing /

 * 5 - The content of a shortcode when it wraps some content.

 *

 * @since 2.5

 * @uses $shortcode_tags

 *

 * @return string The shortcode search regular expression

 */

function get_shortcode_regex() {

	global $shortcode_tags;

	$tagnames = array_keys($shortcode_tags);

	$tagregexp = join( '|', array_map('preg_quote', $tagnames) );

	return '(.?)\[('.$tagregexp.')\b(.*?)(?:(\/))?\](?:(.+?)\[\/\2\])?(.?)';

}

/**

 * Regular Expression callable for do_shortcode() for calling shortcode hook.

 * @see get_shortcode_regex for details of the match array contents.

 *

 * @since 2.5

 * @access private

 * @uses $shortcode_tags

 *

 * @param array $m Regular expression match array

 * @return mixed False on failure.

 */

function do_shortcode_tag($m) {

	global $shortcode_tags;

	// allow [[foo]] syntax for escaping a tag

	if ($m[1] == '[' && $m[6] == ']') {

		return substr($m[0], 1, -1);

	}

	$tag = $m[2];

	$attr = shortcode_parse_atts($m[3]);

	if ( isset($m[5]) ) {

		// enclosing tag - extra parameter

		return $m[1] . call_user_func($shortcode_tags[$tag], $attr, $m[5], $m[2]) . $m[6];

	} else {

		// self-closing tag

		return $m[1] . call_user_func($shortcode_tags[$tag], $attr, NULL, $m[2]) . $m[6];

	}

}

/**

 * Retrieve all attributes from the shortcodes tag.

 *

 * The attributes list has the attribute name as the key and the value of the

 * attribute as the value in the key/value pair. This allows for easier

 * retrieval of the attributes, since all attributes have to be known.

 *

 * @since 2.5

 *

 * @param string $text

 * @return array List of attributes and their value.

 */

function shortcode_parse_atts($text) {

	$atts = array();

	$pattern = '/(\w+)\s*=\s*"([^"]*)"(?:\s|$)|(\w+)\s*=\s*\'([^\']*)\'(?:\s|$)|(\w+)\s*=\s*([^\s\'"]+)(?:\s|$)|"([^"]*)"(?:\s|$)|(\S+)(?:\s|$)/';

	$text = preg_replace("/[\x{00a0}\x{200b}]+/u", " ", $text);

	if ( preg_match_all($pattern, $text, $match, PREG_SET_ORDER) ) {

		foreach ($match as $m) {

			if (!empty($m[1]))

				$atts[strtolower($m[1])] = stripcslashes($m[2]);

			elseif (!empty($m[3]))

				$atts[strtolower($m[3])] = stripcslashes($m[4]);

			elseif (!empty($m[5]))

				$atts[strtolower($m[5])] = stripcslashes($m[6]);

			elseif (isset($m[7]) and strlen($m[7]))

				$atts[] = stripcslashes($m[7]);

			elseif (isset($m[8]))

				$atts[] = stripcslashes($m[8]);

		}

	} else {

		$atts = ltrim($text);

	}

	return $atts;

}

/**

 * Combine user attributes with known attributes and fill in defaults when needed.

 *

 * The pairs should be considered to be all of the attributes which are

 * supported by the caller and given as a list. The returned attributes will

 * only contain the attributes in the $pairs list.

 *

 * If the $atts list has unsupported attributes, then they will be ignored and

 * removed from the final returned list.

 *

 * @since 2.5

 *

 * @param array $pairs Entire list of supported attributes and their defaults.

 * @param array $atts User defined attributes in shortcode tag.

 * @return array Combined and filtered attribute list.

 */

function shortcode_atts($pairs, $atts) {

	$atts = (array)$atts;

	$out = array();

	foreach($pairs as $name => $default) {

		if ( array_key_exists($name, $atts) )

			$out[$name] = $atts[$name];

		else

			$out[$name] = $default;

	}

	return $out;

}

/**

 * Remove all shortcode tags from the given content.

 *

 * @since 2.5

 * @uses $shortcode_tags

 *

 * @param string $content Content to remove shortcode tags.

 * @return string Content without shortcode tags.

 */

function strip_shortcodes( $content ) {

	global $shortcode_tags;

	if (empty($shortcode_tags) || !is_array($shortcode_tags))

		return $content;

	$pattern = get_shortcode_regex();

	return preg_replace('/'.$pattern.'/s', '', $content);

}

add_filter('the_content', 'do_shortcode', 11); // AFTER wpautop()

?>