modules/bidi/bidi.module

<?php // -*-php-*-
/*
 * $Id: bidi.module,v 1.6 2007/01/19 19:38:50 msameer Exp $
 * 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 <msameer@foolab.org>: 2004-10-30
 *                  * Ported to drupal 4.5 API.
 * Mohammed Sameer <msameer@foolab.org>: 2005-04-10
 *                  * Reworked the configuration part for 4.7
 *                  * The arabic to english threshhold is now configurable.
 *                  * Spelling correction: automaticaly -> automatically
 *                  * Some minor code cleanups.
 * Mohammed Sameer <msameer@foolab.org>: 2006-11-13
 *                  * Replaced _get_dir() with bidi_get_dir()
 *                  * bidi_get_dir() returns a direction not a css thing.
 *                  * Added bidi_get_attributes to get the css attributes.
 *                  * Added bidi_get_class() to get the css class
 * Mohammed Sameer <msameer@foolab.org>: 2007-01-19
 *                  * Ported to 5.0
 *                  * bidi_get_{dir|class}() takes a reference.
 *                  * _bidi_filter_process() should take a reference.
 *                  * Started documenting the code.
 *                  * added hook_menu() to load the bidi.css
 *                  * Added _bidi_load_css() to load the CSS file containing our classes.
 * Mohammed Sameer <msameer@foolab.org>: 2008-12-06
 *                  * Ported to Drupal 6
 *                  * _bidi_load_css() -> bidi_init()
 */

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

define('BIDI_DIR_RTL', 1);
define('BIDI_DIR_LTR', 2);

/**
 * 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;
  }
}

/**
 * Implementation of hook_init()
 */
function bidi_init() {
  $path = drupal_get_path('module', 'bidi').'/bidi.css';
  drupal_add_css($path);
}

/**
 * Get the direction of a string.
 *
 * @param $text a reference to the text to be scanned.
 * @return either BIDI_DIR_RTL or BIDI_DIR_LTR
 */
function bidi_get_dir(&$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;
    }
  }

  if ($arabic) {
    if ($english/$arabic < variable_get('bidi_module_threshhold', 1.5)) {
      return BIDI_DIR_RTL;
    }
  }
  return BIDI_DIR_LTR;
}

/**
 * return the CSS class.
 *
 * return "left2right" or "right2left".
 */
function bidi_get_class(&$text) {
  return bidi_get_dir($text) == BIDI_DIR_LTR ? 'left2right' : 'right2left';
}

/**
 * Get the HTML fragment to set the direction.
 *
 * @return the HTML fragment to set the direction.
 */
function bidi_get_attributes($text) {
  return ' class="'.bidi_get_class($text).'" ';
}

/**
 * Scan the body of a node and set the correct direction.
 *
 * @param $text a reference to the text to be modified.
 * @return the text after being processed.
 */
function _bidi_filter_process(&$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;
      $j = 1; //stack counter

      // 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
	if ($text[$i+$e-1] == '<') { //new nested block
	  ++$j;
	} else if ($text[$i+$e-1] == '/') { //end of block
	  --$j;
	}
	$e += 2; //skip current tag
      }
      $content = substr($text, $i+1, $e);
      $output.= bidi_get_attributes(strip_tags($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
      $output.= bidi_get_attributes(strip_tags($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;
}

/**
 * Get the settings form.
 *
 * @return a drupal form array.
 */
function _bidi_filter_settings() {

  $form['bidi_filter'] = array(
			       '#type' => 'fieldset',
			       '#title' => t('BiDi filter'),
			       '#collapsible' => TRUE,
			       '#collapsed' => FALSE,
			       );
  $form['bidi_filter']['bidi_module_threshhold'] = array(
			       '#type' => 'textfield',
			       '#title' => t('Bidi threshhold'),
			       '#default_value' => variable_get('bidi_module_threshhold','1.5'),
			       '#description' => t('Below this threshhold text will take the right to left direction.'),
			       );

  return $form;
}

/**
 * Implementation of hook_filter_tips()
 */
function bidi_filter_tips() {
  return t("You may write mixed Arabic and English freely, line direction will be computed automaticaly");
}

?>
1	<?php // --php--
2	/*
3	* $Id: bidi.module,v 1.6 2007/01/19 19:38:50 msameer Exp $
4	* Original module by Alaa Abd El Fatah.
5	* Mohammed Sameer: My Modifications Copyright (c) 2004 Mohammed Sameer,
6	* under the GNU GPL v2 or later.
7	* Mohammed Sameer <msameer@foolab.org>: 2004-10-30
8	* * Ported to drupal 4.5 API.
9	* Mohammed Sameer <msameer@foolab.org>: 2005-04-10
10	* * Reworked the configuration part for 4.7
11	* * The arabic to english threshhold is now configurable.
12	* * Spelling correction: automaticaly -> automatically
13	* * Some minor code cleanups.
14	* Mohammed Sameer <msameer@foolab.org>: 2006-11-13
15	* * Replaced _get_dir() with bidi_get_dir()
16	* * bidi_get_dir() returns a direction not a css thing.
17	* * Added bidi_get_attributes to get the css attributes.
18	* * Added bidi_get_class() to get the css class
19	* Mohammed Sameer <msameer@foolab.org>: 2007-01-19
20	* * Ported to 5.0
21	* * bidi_get_{dir\|class}() takes a reference.
22	* * _bidi_filter_process() should take a reference.
23	* * Started documenting the code.
24	* * added hook_menu() to load the bidi.css
25	* * Added _bidi_load_css() to load the CSS file containing our classes.
26	* Mohammed Sameer <msameer@foolab.org>: 2008-12-06
27	* * Ported to Drupal 6
28	* * _bidi_load_css() -> bidi_init()
29	*/
30
31	setlocale(LC_ALL, "ar_EG.UTF-8");
32
33	define('BIDI_DIR_RTL', 1);
34	define('BIDI_DIR_LTR', 2);
35
36	/**
37	* Implementation of hook_filter()
38	*/
39	function bidi_filter($op, $delta = 0, $format = -1, $text = "") {
40	switch ($op) {
41	case 'list':
42	return array(0 => t('BiDi'));
43	case 'description':
44	return t("Bidi filter");
45	case "process":
46	return _bidi_filter_process($text);
47	case "settings":
48	return _bidi_filter_settings($text);
49	default:
50	return $text;
51	}
52	}
53
54	/**
55	* Implementation of hook_init()
56	*/
57	function bidi_init() {
58	$path = drupal_get_path('module', 'bidi').'/bidi.css';
59	drupal_add_css($path);
60	}
61
62	/**
63	* Get the direction of a string.
64	*
65	* @param $text a reference to the text to be scanned.
66	* @return either BIDI_DIR_RTL or BIDI_DIR_LTR
67	*/
68	function bidi_get_dir(&$text) {
69	$text = strtolower($text);
70	$len = strlen($text);
71
72	$arabic = 0;
73	$english = 0;
74
75	//constants
76	$a = ord('a');
77	$z = ord('z');
78
79	//arabic UTF-8 letters have one of these values in the 1st byte
80	$ar1 = 0xd8;
81	$ar2 = 0xd9;
82
83	// this calculates the dominant language in the text, most bidi implementations just use the first letter (which may be more efficient)
84	for ($i = 0; $i < $len; ++$i) {
85	$bin = ord($text[$i]);
86
87	if ($bin == $ar1 \|\| $bin == $ar2) {
88	++$arabic;
89	++$i;
90	} else if ($bin >= $a && $bin <= $z) {
91	++$english;
92	}
93	}
94
95	if ($arabic) {
96	if ($english/$arabic < variable_get('bidi_module_threshhold', 1.5)) {
97	return BIDI_DIR_RTL;
98	}
99	}
100	return BIDI_DIR_LTR;
101	}
102
103	/**
104	* return the CSS class.
105	*
106	* return "left2right" or "right2left".
107	*/
108	function bidi_get_class(&$text) {
109	return bidi_get_dir($text) == BIDI_DIR_LTR ? 'left2right' : 'right2left';
110	}
111
112	/**
113	* Get the HTML fragment to set the direction.
114	*
115	* @return the HTML fragment to set the direction.
116	*/
117	function bidi_get_attributes($text) {
118	return ' class="'.bidi_get_class($text).'" ';
119	}
120
121	/**
122	* Scan the body of a node and set the correct direction.
123	*
124	* @param $text a reference to the text to be modified.
125	* @return the text after being processed.
126	*/
127	function _bidi_filter_process(&$text) {
128	$output = "";
129
130	$len = strlen($text);
131	$i = 0;
132
133
134	while ($i < $len) {
135	//find next tag
136	$e = strpos(substr($text, $i), "<");
137	if ($e === FALSE) break;
138
139	$output.=substr($text, $i, $e);
140
141	$i += $e;
142
143	//find end of next tag
144	$e = strcspn(substr($text, $i), "/> ");
145	$tag = substr($text, $i+1, $e-1);
146
147	$output.=substr($text, $i, $e);
148	$i += $e;
149
150
151	switch ($tag) {
152	//single tag entity
153	case "img":
154	case "br":
155	case "hr":
156	continue;
157	break;
158
159	//nested cases
160	case "ul":
161	case "ol":
162	case "dl":
163	case "div":
164	$e = 0;
165	$j = 1; //stack counter
166
167	// if $j = 0 then stack is empty
168	while ($j > 0) {
169	$e += strpos(substr($text, $i+$e) , $tag);
170
171	//yeah I know I'm assuming certain sizes for tags, sue me
172	if ($text[$i+$e-1] == '<') { //new nested block
173	++$j;
174	} else if ($text[$i+$e-1] == '/') { //end of block
175	--$j;
176	}
177	$e += 2; //skip current tag
178	}
179	$content = substr($text, $i+1, $e);
180	$output.= bidi_get_attributes(strip_tags($content));
181	$e += strlen($tag);
182	$output.= substr($text, $i, $e);
183	$i += $e;
184	break;
185
186
187	//block elements these get out attention
188	case "p":
189	case "blockquote":
190	case "pre":
191	case "h1":
192	case "h2":
193	case "h3":
194	case "h4":
195	case "h5":
196	case "h6":
197
198	//nested lists are proken better think of a fix
199	case "li":
200	$close_tag = "</".$tag.">";
201	//breaks on extra whitespaces, maybe I should use regexps instead
202	$e = strpos(substr($text, $i), $close_tag);
203	$content = substr($text, $i+1, $e-1);
204	//calculate directions
205	$output.= bidi_get_attributes(strip_tags($content));
206	$e += strlen($close_tag);
207	$output.= substr($text, $i, $e);
208	$i += $e;
209
210	break;
211
212	//non block tags we are not handeling
213	default:
214	$close_tag = "</".$tag.">";
215	$e = strpos(substr($text, $i), $close_tag) + strlen($close_tag);
216	$output.= substr($text, $i, $e);
217	$i += $e;
218	}
219
220	}
221
222	//any missing content
223	$output .= substr($text, $i);
224
225
226	return $output;
227	}
228
229	/**
230	* Get the settings form.
231	*
232	* @return a drupal form array.
233	*/
234	function _bidi_filter_settings() {
235
236	$form['bidi_filter'] = array(
237	'#type' => 'fieldset',
238	'#title' => t('BiDi filter'),
239	'#collapsible' => TRUE,
240	'#collapsed' => FALSE,
241	);
242	$form['bidi_filter']['bidi_module_threshhold'] = array(
243	'#type' => 'textfield',
244	'#title' => t('Bidi threshhold'),
245	'#default_value' => variable_get('bidi_module_threshhold','1.5'),
246	'#description' => t('Below this threshhold text will take the right to left direction.'),
247	);
248
249	return $form;
250	}
251
252	/**
253	* Implementation of hook_filter_tips()
254	*/
255	function bidi_filter_tips() {
256	return t("You may write mixed Arabic and English freely, line direction will be computed automaticaly");
257	}
258
259	?>