application/bookmark/LinkUtils.php

   1 <?php
   2
   3 use Shaarli\Bookmark\Bookmark;
   4
   5 /**
   6  * Extract title from an HTML document.
   7  *
   8  * @param string $html HTML content where to look for a title.
   9  *
  10  * @return bool|string Extracted title if found, false otherwise.
  11  */
  12 function html_extract_title($html)
  13 {
  14     if (preg_match('!<title.*?>(.*?)</title>!is', $html, $matches)) {
  15         return trim(str_replace("\n", '', $matches[1]));
  16     }
  17     return false;
  18 }
  19
  20 /**
  21  * Extract charset from HTTP header if it's defined.
  22  *
  23  * @param string $header HTTP header Content-Type line.
  24  *
  25  * @return bool|string Charset string if found (lowercase), false otherwise.
  26  */
  27 function header_extract_charset($header)
  28 {
  29     preg_match('/charset=["\']?([^; "\']+)/i', $header, $match);
  30     if (! empty($match[1])) {
  31         return strtolower(trim($match[1]));
  32     }
  33
  34     return false;
  35 }
  36
  37 /**
  38  * Extract charset HTML content (tag <meta charset>).
  39  *
  40  * @param string $html HTML content where to look for charset.
  41  *
  42  * @return bool|string Charset string if found, false otherwise.
  43  */
  44 function html_extract_charset($html)
  45 {
  46     // Get encoding specified in HTML header.
  47     preg_match('#<meta .*charset=["\']?([^";\'>/]+)["\']? */?>#Usi', $html, $enc);
  48     if (!empty($enc[1])) {
  49         return strtolower($enc[1]);
  50     }
  51
  52     return false;
  53 }
  54
  55 /**
  56  * Extract meta tag from HTML content in either:
  57  *   - OpenGraph: <meta property="og:[tag]" ...>
  58  *   - Meta tag: <meta name="[tag]" ...>
  59  *
  60  * @param string $tag  Name of the tag to retrieve.
  61  * @param string $html HTML content where to look for charset.
  62  *
  63  * @return bool|string Charset string if found, false otherwise.
  64  */
  65 function html_extract_tag($tag, $html)
  66 {
  67     $propertiesKey = ['property', 'name', 'itemprop'];
  68     $properties = implode('|', $propertiesKey);
  69     // We need a OR here to accept either 'property=og:noquote' or 'property="og:unrelated og:my-tag"'
  70     $orCondition  = '["\']?(?:og:)?' . $tag . '["\']?|["\'][^\'"]*?(?:og:)?' . $tag . '[^\'"]*?[\'"]';
  71     // Try to retrieve OpenGraph tag.
  72     $ogRegex = '#<meta[^>]+(?:' . $properties . ')=(?:' . $orCondition . ')[^>]*content=(["\'])([^\1]*?)\1.*?>#';
  73     // If the attributes are not in the order property => content (e.g. Github)
  74     // New regex to keep this readable... more or less.
  75     $ogRegexReverse = '#<meta[^>]+content=(["\'])([^\1]*?)\1[^>]+(?:' . $properties . ')=(?:' . $orCondition . ').*?>#';
  76
  77     if (
  78         preg_match($ogRegex, $html, $matches) > 0
  79         || preg_match($ogRegexReverse, $html, $matches) > 0
  80     ) {
  81         return $matches[2];
  82     }
  83
  84     return false;
  85 }
  86
  87 /**
  88  * In a string, converts URLs to clickable bookmarks.
  89  *
  90  * @param string $text       input string.
  91  *
  92  * @return string returns $text with all bookmarks converted to HTML bookmarks.
  93  *
  94  * @see Function inspired from http://www.php.net/manual/en/function.preg-replace.php#85722
  95  */
  96 function text2clickable($text)
  97 {
  98     $regex = '!(((?:https?|ftp|file)://|apt:|magnet:)\S+[a-z0-9\(\)]/?)!si';
  99     return preg_replace($regex, '<a href="$1">$1</a>', $text);
 100 }
 101
 102 /**
 103  * Auto-link hashtags.
 104  *
 105  * @param string $description Given description.
 106  * @param string $indexUrl    Root URL.
 107  *
 108  * @return string Description with auto-linked hashtags.
 109  */
 110 function hashtag_autolink($description, $indexUrl = '')
 111 {
 112     /*
 113      * To support unicode: http://stackoverflow.com/a/35498078/1484919
 114      * \p{Pc} - to match underscore
 115      * \p{N} - numeric character in any script
 116      * \p{L} - letter from any language
 117      * \p{Mn} - any non marking space (accents, umlauts, etc)
 118      */
 119     $regex = '/(^|\s)#([\p{Pc}\p{N}\p{L}\p{Mn}]+)/mui';
 120     $replacement = '$1<a href="' . $indexUrl . './add-tag/$2" title="Hashtag $2">#$2</a>';
 121     return preg_replace($regex, $replacement, $description);
 122 }
 123
 124 /**
 125  * This function inserts &nbsp; where relevant so that multiple spaces are properly displayed in HTML
 126  * even in the absence of <pre>  (This is used in description to keep text formatting).
 127  *
 128  * @param string $text input text.
 129  *
 130  * @return string formatted text.
 131  */
 132 function space2nbsp($text)
 133 {
 134     return preg_replace('/(^| ) /m', '$1&nbsp;', $text);
 135 }
 136
 137 /**
 138  * Format Shaarli's description
 139  *
 140  * @param string $description shaare's description.
 141  * @param string $indexUrl    URL to Shaarli's index.
 142  * @param bool   $autolink    Turn on/off automatic linkifications of URLs and hashtags
 143  *
 144  * @return string formatted description.
 145  */
 146 function format_description($description, $indexUrl = '', $autolink = true)
 147 {
 148     if ($autolink) {
 149         $description = hashtag_autolink(text2clickable($description), $indexUrl);
 150     }
 151
 152     return nl2br(space2nbsp($description));
 153 }
 154
 155 /**
 156  * Generate a small hash for a link.
 157  *
 158  * @param DateTime $date Link creation date.
 159  * @param int      $id   Link ID.
 160  *
 161  * @return string the small hash generated from link data.
 162  */
 163 function link_small_hash($date, $id)
 164 {
 165     return smallHash($date->format(Bookmark::LINK_DATE_FORMAT) . $id);
 166 }
 167
 168 /**
 169  * Returns whether or not the link is an internal note.
 170  * Its URL starts by `?` because it's actually a permalink.
 171  *
 172  * @param string $linkUrl
 173  *
 174  * @return bool true if internal note, false otherwise.
 175  */
 176 function is_note($linkUrl)
 177 {
 178     return isset($linkUrl[0]) && $linkUrl[0] === '?';
 179 }
 180
 181 /**
 182  * Extract an array of tags from a given tag string, with provided separator.
 183  *
 184  * @param string|null $tags      String containing a list of tags separated by $separator.
 185  * @param string      $separator Shaarli's default: ' ' (whitespace)
 186  *
 187  * @return array List of tags
 188  */
 189 function tags_str2array(?string $tags, string $separator): array
 190 {
 191     // For whitespaces, we use the special \s regex character
 192     $separator = $separator === ' ' ? '\s' : $separator;
 193
 194     return preg_split('/\s*' . $separator . '+\s*/', trim($tags) ?? '', -1, PREG_SPLIT_NO_EMPTY);
 195 }
 196
 197 /**
 198  * Return a tag string with provided separator from a list of tags.
 199  * Note that given array is clean up by tags_filter().
 200  *
 201  * @param array|null $tags      List of tags
 202  * @param string     $separator
 203  *
 204  * @return string
 205  */
 206 function tags_array2str(?array $tags, string $separator): string
 207 {
 208     return implode($separator, tags_filter($tags, $separator));
 209 }
 210
 211 /**
 212  * Clean an array of tags: trim + remove empty entries
 213  *
 214  * @param array|null $tags List of tags
 215  * @param string     $separator
 216  *
 217  * @return array
 218  */
 219 function tags_filter(?array $tags, string $separator): array
 220 {
 221     $trimDefault = " \t\n\r\0\x0B";
 222     return array_values(array_filter(array_map(function (string $entry) use ($separator, $trimDefault): string {
 223         return trim($entry, $trimDefault . $separator);
 224     }, $tags ?? [])));
 225 }