aboutsummaryrefslogtreecommitdiffstats
path: root/include/markdown.php
blob: 0947afeff87f6a22abe0b3a08bc09c041237c40e (plain) (blame)
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
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
<?php
/**
 * @file include/markdown.php
 * @brief Some functions for BB conversions for Diaspora protocol.
 */

use Michelf\MarkdownExtra;

use League\HTMLToMarkdown\HtmlConverter;
use League\HTMLToMarkdown\Environment;
use League\HTMLToMarkdown\Converter\ConverterInterface;
use League\HTMLToMarkdown\ElementInterface;

require_once("include/oembed.php");
require_once("include/event.php");
require_once("include/html2bbcode.php");
require_once("include/bbcode.php");


/**
 * @brief Convert Markdown to bbcode.
 *
 * We don't want to support a bbcode specific markdown interpreter
 * and the markdown library we have is pretty good, but provides HTML output.
 * So we'll use that to convert to HTML, then convert the HTML back to bbcode,
 * and then clean up a few Diaspora specific constructs.
 *
 * @param string $s The message as Markdown
 * @param boolean $use_zrl default false
 * @param array $options default empty
 * @return string The message converted to bbcode
 */
function markdown_to_bb($s, $use_zrl = false, $options = []) {

	if(is_array($s)) {
		btlogger('markdown_to_bb called with array. ' . print_r($s, true), LOGGER_NORMAL, LOG_WARNING);
		return '';
	}

	$s = str_replace("&#xD;","\r",$s);
	$s = str_replace("&#xD;\n&gt;","",$s);

	$s = html_entity_decode($s,ENT_COMPAT,'UTF-8');

	// if empty link text replace with the url
	$s = preg_replace("/\[\]\((.*?)\)/ism",'[$1]($1)',$s);

	$x = [
			'text' => $s,
			'zrl' => $use_zrl,
			'options' => $options
	];
	/**
	 * @hooks markdown_to_bb_init
	 *   * \e string \b text - The message as Markdown and what will get returned
	 *   * \e boolean \b zrl
	 *   * \e array \b options
	 */
	call_hooks('markdown_to_bb_init', $x);

	$s = $x['text'];

	// Escaping the hash tags
	$s = preg_replace('/\#([^\s\#])/','&#35;$1',$s);

	$s = MarkdownExtra::defaultTransform($s);

	if($options && $options['preserve_lf']) {
		$s = str_replace(["\r","\n"],["",'<br>'],$s);
	}
	else {
		$s = str_replace("\r","",$s);
	}

	$s = str_replace('&#35;','#',$s);

	$s = html2bbcode($s);

	// Convert everything that looks like a link to a link
	if($use_zrl) {
		if (strpos($s,'[/img]') !== false) {
			$s = preg_replace_callback("/\[img\](.*?)\[\/img\]/ism", 'use_zrl_cb_img', $s);
			$s = preg_replace_callback("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", 'use_zrl_cb_img_x', $s);
		}
		$s = preg_replace_callback("/([^\]\=\{\/]|^)(https?\:\/\/)([a-zA-Z0-9\pL\:\/\-\?\&\;\.\=\_\~\#\%\$\!\+\,\@\(\)]+)/ismu", 'use_zrl_cb_link',$s);
	}
	else {
		$s = preg_replace("/([^\]\=\{\/]|^)(https?\:\/\/)([a-zA-Z0-9\pL\:\/\-\?\&\;\.\=\_\~\#\%\$\!\+\,\@\(\)]+)/ismu", '$1[url=$2$3]$2$3[/url]',$s);
	}

	// remove duplicate adjacent code tags
	$s = preg_replace("/(\[code\])+(.*?)(\[\/code\])+/ism","[code]$2[/code]", $s);

	// Don't show link to full picture (until it is fixed)
	$s = scale_external_images($s, false);

	/**
	 * @hooks markdown_to_bb
	 *   * \e string - The already converted message as bbcode
	 */
	call_hooks('markdown_to_bb', $s);

	return $s;
}

function use_zrl_cb_link($match) {
	$res = '';
	$is_zid = is_matrix_url(trim($match[0]));

	if($is_zid)
		$res = $match[1] . '[zrl=' . $match[2] . $match[3] . ']' . $match[2] . $match[3] . '[/zrl]';
	else
		$res = $match[1] . '[url=' . $match[2] . $match[3] . ']' . $match[2] . $match[3] . '[/url]';

	return $res;
}

function use_zrl_cb_img($match) {
	$res = '';
	$is_zid = is_matrix_url(trim($match[1]));

	if($is_zid)
		$res = '[zmg]' . $match[1] . '[/zmg]';
	else
		$res = $match[0];

	return $res;
}

function use_zrl_cb_img_x($match) {
	$res = '';
	$is_zid = is_matrix_url(trim($match[3]));

	if($is_zid)
		$res = '[zmg=' . $match[1] . 'x' . $match[2] . ']' . $match[3] . '[/zmg]';
	else
		$res = $match[0];

	return $res;
}

/**
 * @brief
 *
 * @param array $match
 * @return string
 */
function bb_to_markdown_share($match) {

	$matches = array();
	$attributes = $match[1];

	$author = "";
	preg_match("/author='(.*?)'/ism", $attributes, $matches);
	if ($matches[1] != "")
		$author = urldecode($matches[1]);

	$link = "";
	preg_match("/link='(.*?)'/ism", $attributes, $matches);
	if ($matches[1] != "")
		$link = $matches[1];

	$avatar = "";
	preg_match("/avatar='(.*?)'/ism", $attributes, $matches);
	if ($matches[1] != "")
		$avatar = $matches[1];

	$profile = "";
	preg_match("/profile='(.*?)'/ism", $attributes, $matches);
	if ($matches[1] != "")
		$profile = $matches[1];

	$posted = "";
	preg_match("/posted='(.*?)'/ism", $attributes, $matches);
	if ($matches[1] != "")
		$posted = $matches[1];

	// message_id is never used, do we still need it?
	$message_id = "";
	preg_match("/message_id='(.*?)'/ism", $attributes, $matches);
	if ($matches[1] != "")
		$message_id = $matches[1];

	if(! $message_id) {
		preg_match("/guid='(.*?)'/ism", $attributes, $matches);
		if ($matches[1] != "")
			$message_id = $matches[1];
	}


	$reldate = datetime_convert('UTC', date_default_timezone_get(), $posted, 'r');

	$headline = '';

	if ($avatar != "")
		$headline .= '[url=' . zid($profile) . '][img]' . $avatar . '[/img][/url]';

	// Bob Smith wrote the following post 2 hours ago

	$fmt = sprintf( t('%1$s wrote the following %2$s %3$s'),
		'[url=' . zid($profile) . ']' . $author . '[/url]',
		'[url=' . zid($link) . ']' . t('post') . '[/url]',
		$reldate
	);

	$headline .= $fmt . "\n\n";

	$text = $headline . trim($match[2]);

	return $text;
}


/**
 * @brief Convert bbcode to Markdown.
 *
 * @param string $Text The message as bbcode
 * @param array $options default empty
 * @return string The message converted to Markdown
 */
function bb_to_markdown($Text, $options = []) {

	/*
	 * Transform #tags, strip off the [url] and replace spaces with underscore
	 */

	$Text = preg_replace_callback('/#\[([zu])rl\=(.*?)\](.*?)\[\/[(zu)]rl\]/i',
		create_function('$match', 'return \'#\'. str_replace(\' \', \'_\', $match[3]);'), $Text);

	$Text = preg_replace('/#\^\[([zu])rl\=(.*?)\](.*?)\[\/([zu])rl\]/i', '[$1rl=$2]$3[/$4rl]', $Text);

	// Converting images with size parameters to simple images. Markdown doesn't know it.
	$Text = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $Text);

	$Text = preg_replace_callback("/\[share(.*?)\](.*?)\[\/share\]/ism", 'bb_to_markdown_share', $Text);

	$x = [ 'bbcode' => $Text, 'options' => $options ];

	/**
	 * @hooks bb_to_markdown_bb
	 *   * \e string \b bbcode - The message as bbcode and what will get returned
	 *   * \e array \b options
	 */
	call_hooks('bb_to_markdown_bb', $x);

	$Text = $x['bbcode'];

	// Convert it to HTML - don't try oembed
	$Text = bbcode($Text, [ 'tryoembed' => false ]);

	// Now convert HTML to Markdown
	$Text = html2markdown($Text);

	//html2markdown adds backslashes infront of hashes after a new line. remove them
	$Text = str_replace("\n\#", "\n#", $Text);

	// If the text going into bbcode() has a plain URL in it, i.e.
	// with no [url] tags around it, it will come out of parseString()
	// looking like: <http://url.com>, which gets removed by strip_tags().
	// So take off the angle brackets of any such URL
	$Text = preg_replace("/<http(.*?)>/is", "http$1", $Text);

	// Remove empty zrl links
	$Text = preg_replace("/\[zrl\=\].*?\[\/zrl\]/is", "", $Text);

	$Text = trim($Text);

	/**
	 * @hooks bb_to_markdown
	 *   * \e string - The already converted message as bbcode and what will get returned
	 */
	call_hooks('bb_to_markdown', $Text);

	return $Text;
}


/**
 * @brief Convert a HTML text into Markdown.
 *
 * This function uses the library league/html-to-markdown for this task.
 *
 * If the HTML text can not get parsed it will return an empty string.
 *
 * @param string $html The HTML code to convert
 * @return string Markdown representation of the given HTML text, empty on error
 */
function html2markdown($html,$options = []) {
	$markdown = '';

	$internal_errors = libxml_use_internal_errors(true);

	$environment = new Environment($options);
	$environment->createDefaultEnvironment();
	$environment->addConverter(new TableConverter());
	$converter = new HtmlConverter($environment);

	try {
		$markdown = $converter->convert($html);
	} catch (InvalidArgumentException $e) {
		logger("Invalid HTML. HTMLToMarkdown library threw an exception.");
	}

	libxml_use_internal_errors($internal_errors);

	return $markdown;
}

// Tables are not an official part of the markdown specification.
// This interface was suggested as a workaround.
// author: Mark Hamstra
// https://github.com/Mark-H/Docs


class TableConverter implements ConverterInterface
{
    /**
     * @param ElementInterface $element
     *
     * @return string
     */
    public function convert(ElementInterface $element)
    {
        switch ($element->getTagName()) {
            case 'tr':
                $line = [];
                $i = 1;
                foreach ($element->getChildren() as $td) {
                    $i++;
                    $v = $td->getValue();
                    $v = trim($v);
                    if ($i % 2 === 0 || $v !== '') {
                        $line[] = $v;
                    }
                }
                return '| ' . implode(' | ', $line) . " |\n";
            case 'td':
            case 'th':
                return trim($element->getValue());
            case 'tbody':
                return trim($element->getValue());
            case 'thead':
                $headerLine = reset($element->getChildren())->getValue();
                $headers = explode(' | ', trim(trim($headerLine, "\n"), '|'));
                $hr = [];
                foreach ($headers as $td) {
                    $length = strlen(trim($td)) + 2;
                    $hr[] = str_repeat('-', $length > 3 ? $length : 3);
                }
                $hr = '|' . implode('|', $hr) . '|';
                return $headerLine . $hr . "\n";
            case 'table':
                $inner = $element->getValue();
                if (strpos($inner, '-----') === false) {
                    $inner = explode("\n", $inner);
                    $single = explode(' | ', trim($inner[0], '|'));
                    $hr = [];
                    foreach ($single as $td) {
                        $length = strlen(trim($td)) + 2;
                        $hr[] = str_repeat('-', $length > 3 ? $length : 3);
                    }
                    $hr = '|' . implode('|', $hr) . '|';
                    array_splice($inner, 1, 0, $hr);
                    $inner = implode("\n", $inner);
                }
                return trim($inner) . "\n\n";
        }
        return $element->getValue();
    }
    /**
     * @return string[]
     */
    public function getSupportedTags()
    {
        return array('table', 'tr', 'thead', 'td', 'tbody');
    }
}