<?php

/**

* 

* Parses for bulleted and numbered lists.

* 

* @category Text

* 

* @package Text_Wiki

* 

* @author Justin Patrin <papercrane@reversefold.com>

* @author Paul M. Jones <pmjones@php.net>

* 

* @license LGPL

* 

* @version $Id: List.php,v 1.1 2006/03/28 04:46:09 ritzmo Exp $

* 

*/

/**

* 

* Parses for bulleted and numbered lists.

* 

* This class implements a Text_Wiki_Parse to find source text marked as

* a bulleted or numbered list.  In short, if a line starts with '* ' then

* it is a bullet list item; if a line starts with '# ' then it is a 

* number list item.  Spaces in front of the * or # indicate an indented

* sub-list.  The list items must be on sequential lines, and may be 

* separated by blank lines to improve readability.  Using a non-* non-#

* non-whitespace character at the beginning of a line ends the list.

*

* @category Text

* 

* @package Text_Wiki

* 

* @author Justin Patrin <papercrane@reversefold.com>

* @author Paul M. Jones <pmjones@php.net>

* 

*/

class Text_Wiki_Parse_List extends Text_Wiki_Parse {

    /**

    * 

    * The regular expression used to parse the source text and find

    * matches conforming to this rule.  Used by the parse() method.

    * 

    * @access public

    * 

    * @var string

    * 

    * @see parse()

    * 

    */

    //TODO: add text continuations (any number of + signs) and expandable areas (- after *s ot #s)

    var $regex = '/\n((?:\*|#)+.*?\n(?!(?:\*|#)+))/s';

    /**

    * 

    * Generates a replacement for the matched text.  Token options are:

    * 

    * 'type' =>

    *     'bullet_start' : the start of a bullet list

    *     'bullet_end'   : the end of a bullet list

    *     'number_start' : the start of a number list

    *     'number_end'   : the end of a number list

    *     'item_start'   : the start of item text (bullet or number)

    *     'item_end'     : the end of item text (bullet or number)

    *     'unknown'      : unknown type of list or item

    *

    * 'level' => the indent level (0 for the first level, 1 for the

    * second, etc)

    *

    * 'count' => the list item number at this level. not needed for

    * xhtml, but very useful for PDF and RTF.

    * 

    * @access public

    *

    * @param array &$matches The array of matches from parse().

    *

    * @return A series of text and delimited tokens marking the different

    * list text and list elements.

    *

    */

    function process(&$matches)

    {

        // the replacement text we will return

        $return = '';

        // the list of post-processing matches

        $list = array();

        // a stack of list-start and list-end types; we keep this

        // so that we know what kind of list we're working with

        // (bullet or number) and what indent level we're at.

        $stack = array();

        // the item count is the number of list items for any

        // given list-type on the stack

        $itemcount = array();

        // have we processed the very first list item?

        $pastFirst = false;

        // populate $list with this set of matches. $matches[1] is the

        // text matched as a list set by parse().

        preg_match_all(

            '/^((\*|#)+)(.*?)$/ms',

            $matches[1],

            $list,

            PREG_SET_ORDER

        );

        // loop through each list-item element.

        foreach ($list as $key => $val) {

            // $val[0] is the full matched list-item line

            // $val[1] is the type (* or #)

            // $val[2] is the level (number)

            // $val[3] is the list item text

            // how many levels are we indented? (1 means the "root"

            // list level, no indenting.)

            $level = strlen($val[1]);

            // get the list item type

            if ($val[2] == '*') {

                $type = 'bullet';

            } elseif ($val[2] == '#') {

                $type = 'number';

            } else {

                $type = 'unknown';

            }

            // get the text of the list item

            $text = $val[3];

            // add a level to the list?

            if ($level > count($stack)) {

                // the current indent level is greater than the

                // number of stack elements, so we must be starting

                // a new list.  push the new list type onto the

                // stack...

                array_push($stack, $type);

                // ...and add a list-start token to the return.

                $return .= $this->wiki->addToken(

                    $this->rule, 

                    array(

                        'type' => $type . '_list_start',

                        'level' => $level - 1

                    )

                );

            }

            // remove a level from the list?

            while (count($stack) > $level) {

                // so we don't keep counting the stack, we set up a temp

                // var for the count.  -1 becuase we're going to pop the

                // stack in the next command.  $tmp will then equal the

                // current level of indent.

                $tmp = count($stack) - 1;

                // as long as the stack count is greater than the

                // current indent level, we need to end list types. 

                // continue adding end-list tokens until the stack count

                // and the indent level are the same.

                $return .= $this->wiki->addToken(

                    $this->rule, 

                    array (

                        'type' => array_pop($stack) . '_list_end',

                        'level' => $tmp

                    )

                );

                // reset to the current (previous) list type so that

                // the new list item matches the proper list type.

                $type = $stack[$tmp - 1];

                // reset the item count for the popped indent level

                unset($itemcount[$tmp + 1]);

            }

            // add to the item count for this list (taking into account

            // which level we are at).

            if (! isset($itemcount[$level])) {

                // first count

                $itemcount[$level] = 0;

            } else {

                // increment count

                $itemcount[$level]++;

            }

            // is this the very first item in the list?

            if (! $pastFirst) {

                $first = true;

                $pastFirst = true;

            } else {

                $first = false;

            }

            // create a list-item starting token.

            $start = $this->wiki->addToken(

                $this->rule, 

                array(

                    'type' => $type . '_item_start',

                    'level' => $level,

                    'count' => $itemcount[$level],

                    'first' => $first

                )

            );

            // create a list-item ending token.

            $end = $this->wiki->addToken(

                $this->rule, 

                array(

                    'type' => $type . '_item_end',

                    'level' => $level,

                    'count' => $itemcount[$level]

                )

            );

            // add the starting token, list-item text, and ending token

            // to the return.

            $return .= $start . $text . $end;

        }

        // the last list-item may have been indented.  go through the

        // list-type stack and create end-list tokens until the stack

        // is empty.

        while (count($stack) > 0) {

            $return .= $this->wiki->addToken(

                $this->rule, 

                array (

                    'type' => array_pop($stack) . '_list_end',

                    'level' => count($stack)

                )

            );

        }

        // we're done!  send back the replacement text.

        return "\n" . $return . "\n\n";

    }

}

?>