<?php

// vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4:

/**

 * Baseline rule class for extension into a "real" parser component.

 *

 * PHP versions 4 and 5

 *

 * @category   Text

 * @package    Text_Wiki

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

 * @license    http://www.gnu.org/copyleft/lesser.html  LGPL License 2.1

 * @version    CVS: $Id: Parse.php,v 1.5 2005/07/29 08:57:29 toggg Exp $

 * @link       http://pear.php.net/package/Text_Wiki

 */

/**

 * Baseline rule class for extension into a "real" parser component.

 *

 * Text_Wiki_Rule classes do not stand on their own; they are called by a

 * Text_Wiki object, typcially in the transform() method. Each rule class

 * performs three main activities: parse, process, and render.

 *

 * The parse() method takes a regex and applies it to the whole block of

 * source text at one time. Each match is sent as $matches to the

 * process() method.

 *

 * The process() method acts on the matched text from the source, and

 * then processes the source text is some way.  This may mean the

 * creation of a delimited token using addToken().  In every case, the

 * process() method returns the text that should replace the matched text

 * from parse().

 *

 * @category   Text

 * @package    Text_Wiki

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

 * @license    http://www.gnu.org/copyleft/lesser.html  LGPL License 2.1

 * @version    Release: @package_version@

 * @link       http://pear.php.net/package/Text_Wiki

 */

class Text_Wiki_Parse {

    /**

    *

    * Configuration options for this parser rule.

    *

    * @access public

    *

    * @var string

    *

    */

    var $conf = array();

    /**

    *

    * Regular expression to find matching text for this rule.

    *

    * @access public

    *

    * @var string

    *

    * @see parse()

    *

    */

    var $regex = null;

    /**

    *

    * The name of this rule for new token array elements.

    *

    * @access public

    *

    * @var string

    *

    */

    var $rule = null;

    /**

    *

    * A reference to the calling Text_Wiki object.

    *

    * This is needed so that each rule has access to the same source

    * text, token set, URLs, interwiki maps, page names, etc.

    *

    * @access public

    *

    * @var object

    */

    var $wiki = null;

    /**

    *

    * Constructor for this parser rule.

    *

    * @access public

    *

    * @param object &$obj The calling "parent" Text_Wiki object.

    *

    */

    function Text_Wiki_Parse(&$obj)

    {

        // set the reference to the calling Text_Wiki object;

        // this allows us access to the shared source text, token

        // array, etc.

        $this->wiki =& $obj;

        // set the name of this rule; generally used when adding

        // to the tokens array. strip off the Text_Wiki_Parse_ portion.

        // text_wiki_parse_

        // 0123456789012345

        $tmp = substr(get_class($this), 16);

        $this->rule = ucwords(strtolower($tmp));

        // override config options for the rule if specified

        if (isset($this->wiki->parseConf[$this->rule]) &&

            is_array($this->wiki->parseConf[$this->rule])) {

            $this->conf = array_merge(

                $this->conf,

                $this->wiki->parseConf[$this->rule]

            );

        }

    }

    /**

    *

    * Abstrct method to parse source text for matches.

    *

    * Applies the rule's regular expression to the source text, passes

    * every match to the process() method, and replaces the matched text

    * with the results of the processing.

    *

    * @access public

    *

    * @see Text_Wiki_Parse::process()

    *

    */

    function parse()

    {

        $this->wiki->source = preg_replace_callback(

            $this->regex,

            array(&$this, 'process'),

            $this->wiki->source

        );

    }

    /**

    *

    * Abstract method to generate replacements for matched text.

    *

    * @access public

    *

    * @param array $matches An array of matches from the parse() method

    * as generated by preg_replace_callback.  $matches[0] is the full

    * matched string, $matches[1] is the first matched pattern,

    * $matches[2] is the second matched pattern, and so on.

    *

    * @return string The processed text replacement; defaults to the

    * full matched string (i.e., no changes to the text).

    *

    * @see Text_Wiki_Parse::parse()

    *

    */

    function process(&$matches)

    {

        return $matches[0];

    }

    /**

    *

    * Simple method to safely get configuration key values.

    *

    * @access public

    *

    * @param string $key The configuration key.

    *

    * @param mixed $default If the key does not exist, return this value

    * instead.

    *

    * @return mixed The configuration key value (if it exists) or the

    * default value (if not).

    *

    */

    function getConf($key, $default = null)

    {

        if (isset($this->conf[$key])) {

            return $this->conf[$key];

        } else {

            return $default;

        }

    }

    /**

    *

    * Extract 'attribute="value"' portions of wiki markup.

    *

    * This kind of markup is typically used only in macros, but is useful

    * anywhere.

    *

    * The syntax is pretty strict; there can be no spaces between the

    * option name, the equals, and the first double-quote; the value

    * must be surrounded by double-quotes.  You can escape characters in

    * the value with a backslash, and the backslash will be stripped for

    * you.

    *

    * @access public

    *

    * @param string $text The "attributes" portion of markup.

    *

    * @return array An associative array of key-value pairs where the

    * key is the option name and the value is the option value.

    *

    */

    function getAttrs($text)

    {

        // find the =" sections;

        $tmp = explode('="', trim($text));

        // basic setup

        $k = count($tmp) - 1;

        $attrs = array();

        $key = null;

        // loop through the sections

        foreach ($tmp as $i => $val) {

            // first element is always the first key

            if ($i == 0) {

                $key = trim($val);

                continue;

            }

            // find the last double-quote in the value.

            // the part to the left is the value for the last key,

            // the part to the right is the next key name

            $pos = strrpos($val, '"');

            $attrs[$key] = stripslashes(substr($val, 0, $pos));

            $key = trim(substr($val, $pos+1));

        }

        return $attrs;

    }

}

?>