<?php
/*
* Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between
* Copyright (C) 2006-2009 Dan Fuhry
*
* This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
*/
/**
* Framework for parsing and rendering various formats. In Enano by default, this is MediaWiki-style wikitext being
* rendered to XHTML, but this framework allows other formats to be supported as well.
*
* @package Enano
* @subpackage Content
* @author Dan Fuhry <dan@enanocms.org>
* @copyright (C) 2009 Enano CMS Project
* @license GNU General Public License, version 2 or later <http://www.gnu.org/licenses/gpl-2.0.html>
*/
class Carpenter
{
/**
* Parser token
* @const string
*/
const PARSER_TOKEN = "\xFF";
/**
* Parsing engine
* @var string
*/
private $parser = 'mediawiki';
/**
* Rendering engine
* @var string
*/
private $renderer = 'xhtml';
/**
* Rendering flags
*/
public $flags = RENDER_WIKI_DEFAULT;
/**
* List of rendering rules
* @var array
*/
private $rules = array(
'lang',
'templates',
'blockquote',
'tables',
'heading',
'hr',
// note: can't be named list ("list" is a PHP language construct)
'multilist',
'bold',
'italic',
'underline',
'externalwithtext',
'externalnotext',
'image',
'internallink',
'paragraph',
'blockquotepost'
);
/**
* List of render hooks
* @var array
*/
private $hooks = array();
/* private $rules = array('prefilter', 'delimiter', 'code', 'function', 'html', 'raw', 'include', 'embed', 'anchor',
'heading', 'toc', 'horiz', 'break', 'blockquote', 'list', 'deflist', 'table', 'image',
'phplookup', 'center', 'newline', 'paragraph', 'url', 'freelink', 'interwiki',
'wikilink', 'colortext', 'strong', 'bold', 'emphasis', 'italic', 'underline', 'tt',
'superscript', 'subscript', 'revise', 'tighten'); */
/**
* Render the text!
* @param string Text to render
* @return string
*/
public function render($text)
{
$parser_class = "Carpenter_Parse_" . ucwords($this->parser);
$renderer_class = "Carpenter_Render_" . ucwords($this->renderer);
// empty?
if ( trim($text) === '' )
return $text;
// include files, if we haven't already
if ( !class_exists($parser_class) )
{
require_once( ENANO_ROOT . "/includes/wikiengine/parse_{$this->parser}.php");
}
if ( !class_exists($renderer_class) )
{
require_once( ENANO_ROOT . "/includes/wikiengine/render_{$this->renderer}.php");
}
$parser = new $parser_class;
$renderer = new $renderer_class;
// run prehooks
foreach ( $this->hooks as $hook )
{
if ( $hook['when'] === PO_FIRST )
{
$text = call_user_func($hook['callback'], $text);
if ( !is_string($text) || empty($text) )
{
trigger_error("Hook returned empty/invalid text: " . print_r($hook['callback'], true), E_USER_WARNING);
// *sigh*
$text = '';
}
}
}
// perform render
foreach ( $this->rules as $rule )
{
// run prehooks
foreach ( $this->hooks as $hook )
{
if ( $hook['when'] === PO_BEFORE && $hook['rule'] === $rule )
{
$text = call_user_func($hook['callback'], $text);
if ( !is_string($text) || empty($text) )
{
trigger_error("Hook returned empty/invalid text: " . print_r($hook['callback'], true), E_USER_WARNING);
// *sigh*
$text = '';
}
}
}
// execute rule
$text_before = $text;
$text = $this->perform_render_step($text, $rule, $parser, $renderer);
if ( empty($text) )
{
trigger_error("Wikitext was empty after rule \"$rule\"; restoring backup", E_USER_WARNING);
$text = $text_before;
}
unset($text_before);
// run posthooks
foreach ( $this->hooks as $hook )
{
if ( $hook['when'] === PO_AFTER && $hook['rule'] === $rule )
{
$text = call_user_func($hook['callback'], $text);
if ( !is_string($text) || empty($text) )
{
trigger_error("Hook returned empty/invalid text: " . print_r($hook['callback'], true), E_USER_WARNING);
// *sigh*
$text = '';
}
}
}
}
// run posthooks
foreach ( $this->hooks as $hook )
{
if ( $hook['when'] === PO_LAST )
{
$text = call_user_func($hook['callback'], $text);
if ( !is_string($text) || empty($text) )
{
trigger_error("Hook returned empty/invalid text: " . print_r($hook['callback'], true), E_USER_WARNING);
// *sigh*
$text = '';
}
}
}
return (( defined('ENANO_DEBUG') && isset($_GET['parserdebug']) ) ? '<pre>' . htmlspecialchars($text) . '</pre>' : $text) . "\n\n";
}
/**
* Performs a step in the rendering process.
* @param string Text to render
* @param string Rule to execute
* @param object Parser instance
* @param object Renderer instance
* @return string
* @access private
*/
private function perform_render_step($text, $rule, $parser, $renderer)
{
// First look for a direct function
if ( function_exists("parser_{$this->parser}_{$this->renderer}_{$rule}") )
{
return call_user_func("parser_{$this->parser}_{$this->renderer}_{$rule}", $text, $this->flags);
}
// We don't have that, so start looking for other ways or means of doing this
if ( method_exists($parser, $rule) && method_exists($renderer, $rule) )
{
// Both the parser and render have callbacks they want to use.
$pieces = $parser->$rule($text);
$text = call_user_func(array($renderer, $rule), $text, $pieces);
}
else if ( method_exists($parser, $rule) && !method_exists($renderer, $rule) && isset($renderer->rules[$rule]) )
{
// The parser has a callback, but the renderer does not
$pieces = $parser->$rule($text);
$text = $this->generic_render($text, $pieces, $renderer->rules[$rule]);
}
else if ( !method_exists($parser, $rule) && isset($parser->rules[$rule]) && method_exists($renderer, $rule) )
{
// The parser has no callback, but the renderer does
$text = preg_replace_callback($parser->rules[$rule], array($renderer, $rule), $text);
}
else if ( isset($parser->rules[$rule]) && isset($renderer->rules[$rule]) )
{
// This is a straight-up regex only rule
$text = preg_replace($parser->rules[$rule], $renderer->rules[$rule], $text);
}
else
{
// Either the renderer or parser does not support this rule, ignore it
}
return $text;
}
/**
* Generic renderer
* @access protected
*/
protected function generic_render($text, $pieces, $rule)
{
foreach ( $pieces as $i => $piece )
{
$replacement = $rule;
// if the piece is an array, replace $1, $2, etc. in the rule with each value in the piece
if ( is_array($piece) )
{
$j = 0;
foreach ( $piece as $part )
{
$j++;
$replacement = str_replace(array("\\$j", "\${$j}"), $part, $replacement);
}
}
// else, just replace \\1 or $1 in the rule with the piece
else
{
$replacement = str_replace(array("\\1", "\$1"), $piece, $replacement);
}
$text = str_replace(self::generate_token($i), $replacement, $text);
}
return $text;
}
/**
* Add a hook into the parser.
* @param callback Function to call
* @param int PO_* constant
* @param string If PO_{BEFORE,AFTER} used, rule
*/
public function hook($callback, $when, $rule = false)
{
if ( !is_int($when) )
return null;
if ( ($when == PO_BEFORE || $when == PO_AFTER) && !is_string($rule) )
return null;
if ( ( is_string($callback) && !function_exists($callback) ) || ( is_array($callback) && !method_exists($callback[0], $callback[1]) ) || ( !is_string($callback) && !is_array($callback) ) )
{
trigger_error("Attempt to hook with undefined function/method " . print_r($callback, true), E_USER_ERROR);
return null;
}
$this->hooks[] = array(
'callback' => $callback,
'when' => $when,
'rule' => $rule
);
}
/**
* Disable a render stage
* @param string stage
* @return null
*/
public function disable_rule($rule)
{
foreach ( $this->rules as $i => $current_rule )
{
if ( $current_rule === $rule )
{
unset($this->rules[$i]);
return null;
}
}
return null;
}
/**
* Disables all rules.
* @return null
*/
public function disable_all_rules()
{
$this->rules = array();
return null;
}
/**
* Enables a rule
* @param string rule
* @return null
*/
public function enable_rule($rule)
{
$this->rules[] = $rule;
return null;
}
/**
* Make a rule exclusive (the only one called)
* @param string stage
* @return null
*/
public function exclusive_rule($rule)
{
if ( is_string($rule) )
$this->rules = array($rule);
return null;
}
/**
* Generate a token
* @param int Token index
* @return string
* @static
*/
public static function generate_token($i)
{
return self::PARSER_TOKEN . $i . self::PARSER_TOKEN;
}
/**
* Tokenize string
* @param string
* @param array Matches
* @return string
* @static
*/
public static function tokenize($text, $matches)
{
$matches = array_values($matches);
foreach ( $matches as $i => $match )
{
$text = str_replace_once($match, self::generate_token($i), $text);
}
return $text;
}
}