aboutsummaryrefslogtreecommitdiff
path: root/lib_autolink.php
blob: da39c03321cfbcc2b181b3e7d22706e2c589d514 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
<?php
	#
	# A PHP auto-linking library
	#
	# https://github.com/iamcal/lib_autolink
	#
	# By Cal Henderson <cal@iamcal.com>
	# This code is licensed under the MIT license
	#

	####################################################################

	#
	# These are global options. You can set them before calling the autolinking
	# functions to change the output.
	#

	$GLOBALS['autolink_options'] = array(

		# Should http:// be visibly stripped from the front
		# of URLs?
		'strip_protocols' => true,

	);

	####################################################################

	function autolink($text, $limit=30, $tagfill='', $auto_title = true){

		$text = autolink_do($text, '![a-z][a-z-]+://!i',	$limit, $tagfill, $auto_title);
		$text = autolink_do($text, '!(mailto|skype):!i',	$limit, $tagfill, $auto_title);
		$text = autolink_do($text, '!www\\.!i',			$limit, $tagfill, $auto_title, 'http://');
		return $text;
	}

	####################################################################

	function autolink_do($text, $sub, $limit, $tagfill, $auto_title, $force_prefix=null){

		$text_l = StrToLower($text);
		$cursor = 0;
		$loop = 1;
		$buffer = '';

		while (($cursor < strlen($text)) && $loop){

			$ok = 1;
			$matched = preg_match($sub, $text_l, $m, PREG_OFFSET_CAPTURE, $cursor);

			if (!$matched){

				$loop = 0;
				$ok = 0;

			}else{

				$pos = $m[0][1];
				$sub_len = strlen($m[0][0]);

				$pre_hit = substr($text, $cursor, $pos-$cursor);
				$hit = substr($text, $pos, $sub_len);
				$pre = substr($text, 0, $pos);
				$post = substr($text, $pos + $sub_len);

				$fail_text = $pre_hit.$hit;
				$fail_len = strlen($fail_text);

				#
				# substring found - first check to see if we're inside a link tag already...
				#

				$bits = preg_split("!</a>!i", $pre);
				$last_bit = array_pop($bits);
				if (preg_match("!<a\s!i", $last_bit)){

					#echo "fail 1 at $cursor<br />\n";

					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}

			#
			# looks like a nice spot to autolink from - check the pre
			# to see if there was whitespace before this match
			#

			if ($ok){

				if ($pre){
					if (!preg_match('![\s\(\[\{>\pZ\p{Cc}]$!s', $pre)){

						#echo "fail 2 at $cursor ($pre)<br />\n";

						$ok = 0;
						$cursor += $fail_len;
						$buffer .= $fail_text;
					}
				}
			}

			#
			# we want to autolink here - find the extent of the url
			#

			if ($ok){
				if (preg_match('/^([a-z0-9\-\.\/\-_%~!?=,:;&+*#@\(\)\$]+)/i', $post, $matches)){

					$url = $hit.$matches[1];

					$cursor += strlen($url) + strlen($pre_hit);
					$buffer .= $pre_hit;

					$url = html_entity_decode($url);


					#
					# remove trailing punctuation from url
					#

					while (preg_match('|[.,!;:?]$|', $url)){
						$url = substr($url, 0, strlen($url)-1);
						$cursor--;
					}
					foreach (array('()', '[]', '{}') as $pair){
						$o = substr($pair, 0, 1);
						$c = substr($pair, 1, 1);
						if (preg_match("!^(\\$c|^)[^\\$o]+\\$c$!", $url)){
							$url = substr($url, 0, strlen($url)-1);
							$cursor--;
						}
					}


					#
					# nice-i-fy url here
					#

					$link_url = $url;
					$display_url = $url;

					if ($force_prefix) $link_url = $force_prefix.$link_url;

					if ($GLOBALS['autolink_options']['strip_protocols']){
						if (preg_match('!^(http|https)://!i', $display_url, $m)){

							$display_url = substr($display_url, strlen($m[1])+3);
						}
					}

					$display_url = autolink_label($display_url, $limit);


					#
					# add the url
					#

					$currentTagfill = $tagfill;
					if ($display_url != $link_url && !preg_match('@title=@msi',$currentTagfill) && $auto_title) {

						$display_quoted = preg_quote($display_url, '!');

						if (!preg_match("!^(http|https)://{$display_quoted}$!i", $link_url)){

							$currentTagfill .= ' title="'.$link_url.'"';
						}
					}

					$link_url_enc = HtmlSpecialChars($link_url);
					$display_url_enc = HtmlSpecialChars($display_url);

					$buffer .= "<a href=\"{$link_url_enc}\"$currentTagfill>{$display_url_enc}</a>";

				}else{
					#echo "fail 3 at $cursor<br />\n";

					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}

		}

		#
		# add everything from the cursor to the end onto the buffer.
		#

		$buffer .= substr($text, $cursor);

		return $buffer;
	}

	####################################################################

	function autolink_label($text, $limit){

		if (!$limit){ return $text; }

		if (strlen($text) > $limit){
			return substr($text, 0, $limit-3).'...';
		}

		return $text;
	}

	####################################################################

	function autolink_email($text, $tagfill=''){

		$atom = '[^()<>@,;:\\\\".\\[\\]\\x00-\\x20\\x7f]+'; # from RFC822

		#die($atom);

		$text_l = StrToLower($text);
		$cursor = 0;
		$loop = 1;
		$buffer = '';

		while(($cursor < strlen($text)) && $loop){

			#
			# find an '@' symbol
			#

			$ok = 1;
			$pos = strpos($text_l, '@', $cursor);

			if ($pos === false){

				$loop = 0;
				$ok = 0;

			}else{

				$pre = substr($text, $cursor, $pos-$cursor);
				$hit = substr($text, $pos, 1);
				$post = substr($text, $pos + 1);

				$fail_text = $pre.$hit;
				$fail_len = strlen($fail_text);

				#die("$pre::$hit::$post::$fail_text");

				#
				# substring found - first check to see if we're inside a link tag already...
				#

				$bits = preg_split("!</a>!i", $pre);
				$last_bit = array_pop($bits);
				if (preg_match("!<a\s!i", $last_bit)){

					#echo "fail 1 at $cursor<br />\n";

					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}

			#
			# check backwards
			#

			if ($ok){
				if (preg_match("!($atom(\.$atom)*)\$!", $pre, $matches)){

					# move matched part of address into $hit

					$len = strlen($matches[1]);
					$plen = strlen($pre);

					$hit = substr($pre, $plen-$len).$hit;
					$pre = substr($pre, 0, $plen-$len);

				}else{

					#echo "fail 2 at $cursor ($pre)<br />\n";

					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}

			#
			# check forwards
			#

			if ($ok){
				if (preg_match("!^($atom(\.$atom)*)!", $post, $matches)){

					# move matched part of address into $hit

					$len = strlen($matches[1]);

					$hit .= substr($post, 0, $len);
					$post = substr($post, $len);

				}else{
					#echo "fail 3 at $cursor ($post)<br />\n";

					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}

			#
			# commit
			#

			if ($ok) {

				$cursor += strlen($pre) + strlen($hit);
				$buffer .= $pre;
				$buffer .= "<a href=\"mailto:$hit\"$tagfill>$hit</a>";

			}

		}

		#
		# add everything from the cursor to the end onto the buffer.
		#

		$buffer .= substr($text, $cursor);

		return $buffer;
	}

	####################################################################

?>