sandbox/alaa/bidi.module

<?php // -*-php-*-
/*
 * Original module by Alaa Abd El Fatah.
 * Mohammed Sameer: My Modifications Copyright (c) 2004 Mohammed Sameer, 
 *                  under the GNU GPL v2 or later.
 * Mohammed Sameer: 2004 10 30
 *                  * Ported to drupal 4.5 API.
 *
 * 04/04/2005 Ported to drupal 4.6 API by Amr Mostafa
 */

setlocale(LC_ALL, "ar_EG.UTF-8");


/**
 * Implementation of hook_help()
 */
function bidi_help($section) {
  $output = "";

  switch ($section) {
    case 'admin/modules#description':
      $output = t("Automaticaly sets line direction");
      break;
  }

  return $output;
}

/**
 * Implementation of hook_filter_tips()
 */
function bidi_filter_tips($delta, $format, $long = false) {
  if ($long) {
    return t("You may write mixed Arabic and English freely, line direction will be computed automaticaly");
  }
  else {
    return t("You may write mixed Arabic and English freely, line direction will be computed automaticaly");
  }
}

/**
 * Implementation of hook_filter()
 */
function bidi_filter($op, $delta = 0, $format = -1, $text = "") {
  switch ($op) {
    case 'list':
      return array(0 => t('BiDi'));
    case 'description':
      return t("Bidi filter");
    case "process":
        return _bidi_filter_process($text);
    case "settings":
        return _bidi_filter_settings($text);
    default:
        return $text;
  }
}

/**
 * Determine text language (arabic or english).
 * This function needs to be split into a single include file so it can be used on theme and other places.
 *
 * @param $text
 *   The text needs to be.
 * @return
 *   right2left or left2right depending on the detected language.
 */
function _get_dir($text) {
  $text = strtolower($text);
  $len = strlen($text);
  
  $arabic = 0;
  $english = 0;
  
  // constants
  $a = ord('a');
  $z = ord('z');
  
  // arabic UTF-8 letters have one of these values in the 1st byte
  $ar1 = 0xd8;
  $ar2 = 0xd9;
  
  // this calculates the dominant language in the text, most bidi implementations just use the first letter (which may be more efficient)
  for ($i = 0; $i < $len; ++$i) {
    $bin = ord($text[$i]);
    
    if ($bin == $ar1 || $bin == $ar2) {
      ++$arabic;
      ++$i;
    }
    else if ($bin >= $a && $bin <= $z) {
      ++$english;
    }
  }
  
  // should this return a bool instead?
  if ($english || $arabic) {
    if ($english > $arabic)	
      return ' class="left2right"';
    else
      return ' class="right2left"';
  }
  else {
    return "";
  }
}

/**
 * Sets HTML text line directions (rtl or ltr) as needed.
 *
 * @param $text
 *   The HTML text needs to be processed.
 *
 * @return
 *   The processed result, with line directions are set using css
 *   classes "righ2left" and "left2right".
 */
function _bidi_filter_process($text) {
  $output = "";
  
  $len = strlen($text);
  $i = 0;
  
  while ($i < $len) {
    // find next tag
    $e = strpos(substr($text, $i), "<");
    if ($e === FALSE) {
      break;
    }
    
    $output .= substr($text, $i, $e);
    
    $i += $e;
    
    // find end of next tag
    $e = strcspn(substr($text, $i), "/> ");
    $tag = substr($text, $i+1, $e-1);
    
    $output .= substr($text, $i, $e);
    $i += $e;
    
    switch ($tag) {
      // single tag entity
      case "img":
      case "br":
      case "hr":
        continue;
        break;
      
      //nested cases
      case "ul":
      case "ol":
      case "dl":
      case "div":
        $e = 0;
        // stack counter
        $j = 1;
        
        // if $j = 0 then stack is empty
        while ($j > 0) {
          $e += strpos(substr($text, $i+$e) , $tag);
          
          // yeah I know I'm assuming certain sizes for tags, sue me
          // new nested block
          if ($text[$i+$e-1] == '<') {
            ++$j;
          }
          // end of block
          else if ($text[$i+$e-1] == '/') {
            --$j;
          }
          // skip current tag
          $e += 2;
        }
        
        $content = substr($text, $i+1, $e); 
        $output .= _get_dir(strip_tags($content));
        $e += strlen($tag);
        $output.= substr($text, $i, $e);
        $i += $e;
        break;
      
      // block elements these get out attention
      case "p":
      case "blockquote":
      case "pre":
      case "h1":
      case "h2":
      case "h3":
      case "h4":
      case "h5":
      case "h6":
      
      // nested lists are proken better think of a fix
      case "li":
        $close_tag = "</".$tag.">";
        // breaks on extra whitespaces, maybe I should use regexps instead
        $e = strpos(substr($text, $i), $close_tag);
        $content = substr($text, $i+1, $e-1);
        // calculate directions
        $output.= _get_dir(strip_tags($content));
        $e += strlen($close_tag);
        $output.= substr($text, $i, $e);
        $i += $e;
        break;
      
      // non block tags we are not handeling
      default:
        $close_tag = "</".$tag.">";
        $e = strpos(substr($text, $i), $close_tag) + strlen($close_tag);
        $output.= substr($text, $i, $e);
        $i += $e;
      }
  }
  
  // any missing content
  $output .= substr($text, $i);
  
  return $output;
}

/**
 * Filter settings.
 *
 * @return
 *   HTML form for filter settings.
 */
function _bidi_filter_settings() {
  return form_group(t("Bidi filter"), t("automatic bidi"));
}

?>
1	alaa	1.1	<?php // --php--
2			/*
3			* Original module by Alaa Abd El Fatah.
4			* Mohammed Sameer: My Modifications Copyright (c) 2004 Mohammed Sameer,
5			* under the GNU GPL v2 or later.
6			* Mohammed Sameer: 2004 10 30
7			* * Ported to drupal 4.5 API.
8	alaa	1.2	*
9			* 04/04/2005 Ported to drupal 4.6 API by Amr Mostafa
10	alaa	1.1	*/
11
12			setlocale(LC_ALL, "ar_EG.UTF-8");
13
14	alaa	1.2
15			/**
16			* Implementation of hook_help()
17			*/
18	alaa	1.1	function bidi_help($section) {
19			$output = "";
20
21			switch ($section) {
22			case 'admin/modules#description':
23			$output = t("Automaticaly sets line direction");
24			break;
25			}
26
27			return $output;
28			}
29
30	alaa	1.2	/**
31			* Implementation of hook_filter_tips()
32			*/
33			function bidi_filter_tips($delta, $format, $long = false) {
34			if ($long) {
35			return t("You may write mixed Arabic and English freely, line direction will be computed automaticaly");
36			}
37			else {
38			return t("You may write mixed Arabic and English freely, line direction will be computed automaticaly");
39			}
40			}
41	alaa	1.1
42	alaa	1.2	/**
43			* Implementation of hook_filter()
44			*/
45	alaa	1.1	function bidi_filter($op, $delta = 0, $format = -1, $text = "") {
46			switch ($op) {
47	alaa	1.2	case 'list':
48			return array(0 => t('BiDi'));
49			case 'description':
50			return t("Bidi filter");
51			case "process":
52			return _bidi_filter_process($text);
53			case "settings":
54			return _bidi_filter_settings($text);
55			default:
56			return $text;
57	alaa	1.1	}
58			}
59
60	alaa	1.2	/**
61			* Determine text language (arabic or english).
62			* This function needs to be split into a single include file so it can be used on theme and other places.
63			*
64			* @param $text
65			* The text needs to be.
66			* @return
67			* right2left or left2right depending on the detected language.
68			*/
69	alaa	1.1	function _get_dir($text) {
70			$text = strtolower($text);
71			$len = strlen($text);
72	alaa	1.2
73	alaa	1.1	$arabic = 0;
74			$english = 0;
75
76	alaa	1.2	// constants
77	alaa	1.1	$a = ord('a');
78			$z = ord('z');
79
80	alaa	1.2	// arabic UTF-8 letters have one of these values in the 1st byte
81	alaa	1.1	$ar1 = 0xd8;
82			$ar2 = 0xd9;
83	alaa	1.2
84	alaa	1.1	// this calculates the dominant language in the text, most bidi implementations just use the first letter (which may be more efficient)
85			for ($i = 0; $i < $len; ++$i) {
86			$bin = ord($text[$i]);
87	alaa	1.2
88	alaa	1.1	if ($bin == $ar1 \|\| $bin == $ar2) {
89			++$arabic;
90			++$i;
91	alaa	1.2	}
92			else if ($bin >= $a && $bin <= $z) {
93	alaa	1.1	++$english;
94			}
95			}
96	alaa	1.2
97			// should this return a bool instead?
98	alaa	1.1	if ($english \|\| $arabic) {
99			if ($english > $arabic)
100			return ' class="left2right"';
101			else
102			return ' class="right2left"';
103	alaa	1.2	}
104			else {
105	alaa	1.1	return "";
106			}
107			}
108
109	alaa	1.2	/**
110			* Sets HTML text line directions (rtl or ltr) as needed.
111			*
112			* @param $text
113			* The HTML text needs to be processed.
114			*
115			* @return
116			* The processed result, with line directions are set using css
117			* classes "righ2left" and "left2right".
118			*/
119	alaa	1.1	function _bidi_filter_process($text) {
120			$output = "";
121	alaa	1.2
122	alaa	1.1	$len = strlen($text);
123			$i = 0;
124
125			while ($i < $len) {
126	alaa	1.2	// find next tag
127	alaa	1.1	$e = strpos(substr($text, $i), "<");
128	alaa	1.2	if ($e === FALSE) {
129			break;
130			}
131	alaa	1.1
132	alaa	1.2	$output .= substr($text, $i, $e);
133	alaa	1.1
134			$i += $e;
135
136	alaa	1.2	// find end of next tag
137			$e = strcspn(substr($text, $i), "/> ");
138	alaa	1.1	$tag = substr($text, $i+1, $e-1);
139	alaa	1.2
140			$output .= substr($text, $i, $e);
141	alaa	1.1	$i += $e;
142
143			switch ($tag) {
144	alaa	1.2	// single tag entity
145			case "img":
146			case "br":
147			case "hr":
148			continue;
149			break;
150
151	alaa	1.1	//nested cases
152	alaa	1.2	case "ul":
153			case "ol":
154			case "dl":
155			case "div":
156			$e = 0;
157			// stack counter
158			$j = 1;
159
160			// if $j = 0 then stack is empty
161			while ($j > 0) {
162			$e += strpos(substr($text, $i+$e) , $tag);
163
164			// yeah I know I'm assuming certain sizes for tags, sue me
165			// new nested block
166			if ($text[$i+$e-1] == '<') {
167			++$j;
168			}
169			// end of block
170			else if ($text[$i+$e-1] == '/') {
171			--$j;
172			}
173			// skip current tag
174			$e += 2;
175			}
176
177			$content = substr($text, $i+1, $e);
178			$output .= _get_dir(strip_tags($content));
179			$e += strlen($tag);
180			$output.= substr($text, $i, $e);
181			$i += $e;
182			break;
183	alaa	1.1
184	alaa	1.2	// block elements these get out attention
185			case "p":
186			case "blockquote":
187			case "pre":
188			case "h1":
189			case "h2":
190			case "h3":
191			case "h4":
192			case "h5":
193			case "h6":
194	alaa	1.1
195	alaa	1.2	// nested lists are proken better think of a fix
196			case "li":
197			$close_tag = "</".$tag.">";
198			// breaks on extra whitespaces, maybe I should use regexps instead
199			$e = strpos(substr($text, $i), $close_tag);
200			$content = substr($text, $i+1, $e-1);
201			// calculate directions
202			$output.= _get_dir(strip_tags($content));
203			$e += strlen($close_tag);
204			$output.= substr($text, $i, $e);
205			$i += $e;
206			break;
207	alaa	1.1
208	alaa	1.2	// non block tags we are not handeling
209			default:
210			$close_tag = "</".$tag.">";
211			$e = strpos(substr($text, $i), $close_tag) + strlen($close_tag);
212			$output.= substr($text, $i, $e);
213			$i += $e;
214			}
215	alaa	1.1	}
216	alaa	1.2
217			// any missing content
218	alaa	1.1	$output .= substr($text, $i);
219
220	alaa	1.2	return $output;
221	alaa	1.1	}
222
223	alaa	1.2	/**
224			* Filter settings.
225			*
226			* @return
227			* HTML form for filter settings.
228			*/
229	alaa	1.1	function _bidi_filter_settings() {
230			return form_group(t("Bidi filter"), t("automatic bidi"));
231			}
232
233			?>