Parse.php

<?php

namespace Geeklog\Text\Wiki;

use Geeklog\Text\Wiki;

/**
 * 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 191781 2005-07-29 08:57:29Z toggg $
 * @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.
     *
     * @var string
     */
    public $conf = array();

    /**
     * Regular expression to find matching text for this rule.
     *
     * @var string
     * @see    parse()
     */
    public $regex = null;

    /**
     * The name of this rule for new token array elements.
     *
     * @var string
     */
    public $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.
     *
     * @var object
     */
    public $wiki = null;

    /**
     * Constructor for this parser rule.
     *
     * @param Wiki $obj The calling "parent" Text_Wiki object.
     */
    public function __construct(Wiki $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.
        $tmp = str_ireplace('Geeklog\\Text\\Wiki\\Text_Wiki_Parse_', '', get_class($this));
        $this->rule = ucwords(strtolower($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.
     *
     * @see    Text_Wiki_Parse::process()
     */
    public function parse()
    {
        $this->wiki->source = preg_replace_callback(
            $this->regex,
            array($this, 'process'),
            $this->wiki->source
        );
    }

    /**
     * Abstract method to generate replacements for matched text.
     *
     * @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,
     *                        $matches[2] is the second matched pattern, and so on.
     * @return string The processed text replacement; defaults to the
     *                        full matched string (i.e., no changes to the text).
     * @see    Text_Wiki_Parse::parse()
     */
    public function process(&$matches)
    {
        return $matches[0];
    }

    /**
     * Simple method to safely get configuration key values.
     *
     * @param string $key     The configuration key.
     * @param mixed  $default If the key does not exist, return this value
     *                        instead.
     * @return mixed The configuration key value (if it exists) or the
     *                        default value (if not).
     */
    public function getConf($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.
     *
     * @param string $text The "attributes" portion of markup.
     * @return array An associative array of key-value pairs where the
     *                     key is the option name and the value is the option value.
     */
    public function getAttrs($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;
    }
}