source: trunk/www.guidonia.net/wp/wp-content/plugins/contact-form-7/includes/shortcodes.php@ 44

<?php

class WPCF7_ShortcodeManager {

        var $shortcode_tags = array();

        // Taggs scanned at the last time of do_shortcode()
        var $scanned_tags = null;

        // Executing shortcodes (true) or just scanning (false)
        var $exec = true;

        function add_shortcode( $tag, $func, $has_name = false ) {
                if ( is_callable( $func ) )
                        $this->shortcode_tags[$tag] = array(
                                'function' => $func,
                                'has_name' => (boolean) $has_name );
        }

        function remove_shortcode( $tag ) {
                unset( $this->shortcode_tags[$tag] );
        }

        function do_shortcode( $content, $exec = true ) {
                $this->exec = (bool) $exec;
                $this->scanned_tags = array();

                if ( empty( $this->shortcode_tags ) || ! is_array( $this->shortcode_tags) )
                        return $content;

                $pattern = $this->get_shortcode_regex();
                return preg_replace_callback( '/' . $pattern . '/s',
                        array(&$this, 'do_shortcode_tag'), $content );
        }

        function scan_shortcode( $content ) {
                $this->do_shortcode( $content, false );
                return $this->scanned_tags;
        }

        function get_shortcode_regex() {
                $tagnames = array_keys( $this->shortcode_tags );
                $tagregexp = join( '|', array_map( 'preg_quote', $tagnames ) );

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

        function do_shortcode_tag( $m ) {
                // allow [[foo]] syntax for escaping a tag
                if ( $m[1] == '[' && $m[6] == ']' ) {
                        return substr( $m[0], 1, -1 );
                }

                $tag = $m[2];
                $attr = $this->shortcode_parse_atts( $m[3] );

                $scanned_tag = array();
                $scanned_tag['type'] = $tag;

                if ( is_array( $attr ) ) {
                        if ( is_array( $attr['options'] ) && ! empty( $attr['options'] ) ) {
                                if ( $this->shortcode_tags[$tag]['has_name'] )
                                        $scanned_tag['name'] = array_shift( $attr['options'] );
                                $scanned_tag['options'] = $attr['options'];
                        }
                        $scanned_tag['raw_values'] = (array) $attr['values'];

                        if ( WPCF7_USE_PIPE ) {
                                $pipes = new WPCF7_Pipes( $scanned_tag['raw_values'] );
                                $scanned_tag['values'] = $pipes->collect_befores();
                                $scanned_tag['pipes'] = $pipes;
                        } else {
                                $scanned_tag['values'] = $scanned_tag['raw_values'];
                        }

                } else {
                        $scanned_tag['attr'] = $attr;
                }

                $content = trim( $m[5] );
                $content = preg_replace( "/<br\s*\/?>$/m", '', $content );
                $scanned_tag['content'] = $content;

                $this->scanned_tags[] = $scanned_tag;

                $func = $this->shortcode_tags[$tag]['function'];

                if ( $this->exec ) {
                        $scanned_tag = apply_filters( 'wpcf7_form_tag', $scanned_tag );
                        return $m[1] . call_user_func( $func, $scanned_tag ) . $m[6];
                } else {
                        return $m[0];
                }
        }

        function shortcode_parse_atts( $text ) {
                $atts = array();
                $text = preg_replace( "/[\x{00a0}\x{200b}]+/u", " ", $text );
                $text = stripcslashes( trim( $text ) );

                $pattern = '%^([-0-9a-zA-Z:.#_/|\s]*?)((?:\s*"[^"]*"|\s*\'[^\']*\')*)$%';

                if ( preg_match( $pattern, $text, $match ) ) {
                        if ( ! empty( $match[1] ) ) {
                                $atts['options'] = preg_split( '/[\s]+/', trim( $match[1] ) );
                        }
                        if ( ! empty( $match[2] ) ) {
                                preg_match_all( '/"[^"]*"|\'[^\']*\'/', $match[2], $matched_values );
                                $atts['values'] = wpcf7_strip_quote_deep( $matched_values[0] );
                        }
                } else {
                        $atts = $text;
                }

                return $atts;
        }

}

$wpcf7_shortcode_manager = new WPCF7_ShortcodeManager();

function wpcf7_add_shortcode( $tag, $func, $has_name = false ) {
        global $wpcf7_shortcode_manager;

        return $wpcf7_shortcode_manager->add_shortcode( $tag, $func, $has_name );
}

function wpcf7_remove_shortcode( $tag ) {
        global $wpcf7_shortcode_manager;

        return $wpcf7_shortcode_manager->remove_shortcode( $tag );
}

function wpcf7_do_shortcode( $content ) {
        global $wpcf7_shortcode_manager;

        return $wpcf7_shortcode_manager->do_shortcode( $content );
}

function wpcf7_get_shortcode_regex() {
        global $wpcf7_shortcode_manager;

        return $wpcf7_shortcode_manager->get_shortcode_regex();
}

?>