application/LinkUtils.php

   1 <?php
   2
   3 /**
   4  * Extract title from an HTML document.
   5  *
   6  * @param string $html HTML content where to look for a title.
   7  *
   8  * @return bool|string Extracted title if found, false otherwise.
   9  */
  10 function html_extract_title($html)
  11 {
  12     if (preg_match('!<title.*?>(.*?)</title>!is', $html, $matches)) {
  13         return trim(str_replace("\n", '', $matches[1]));
  14     }
  15     return false;
  16 }
  17
  18 /**
  19  * Determine charset from downloaded page.
  20  * Priority:
  21  *   1. HTTP headers (Content type).
  22  *   2. HTML content page (tag <meta charset>).
  23  *   3. Use a default charset (default: UTF-8).
  24  *
  25  * @param array  $headers           HTTP headers array.
  26  * @param string $htmlContent       HTML content where to look for charset.
  27  * @param string $defaultCharset    Default charset to apply if other methods failed.
  28  *
  29  * @return string Determined charset.
  30  */
  31 function get_charset($headers, $htmlContent, $defaultCharset = 'utf-8')
  32 {
  33     if ($charset = headers_extract_charset($headers)) {
  34         return $charset;
  35     }
  36
  37     if ($charset = html_extract_charset($htmlContent)) {
  38         return $charset;
  39     }
  40
  41     return $defaultCharset;
  42 }
  43
  44 /**
  45  * Extract charset from HTTP headers if it's defined.
  46  *
  47  * @param array $headers HTTP headers array.
  48  *
  49  * @return bool|string Charset string if found (lowercase), false otherwise.
  50  */
  51 function headers_extract_charset($headers)
  52 {
  53     if (! empty($headers['Content-Type']) && strpos($headers['Content-Type'], 'charset=') !== false) {
  54         preg_match('/charset="?([^; ]+)/i', $headers['Content-Type'], $match);
  55         if (! empty($match[1])) {
  56             return strtolower(trim($match[1]));
  57         }
  58     }
  59
  60     return false;
  61 }
  62
  63 /**
  64  * Extract charset HTML content (tag <meta charset>).
  65  *
  66  * @param string $html HTML content where to look for charset.
  67  *
  68  * @return bool|string Charset string if found, false otherwise.
  69  */
  70 function html_extract_charset($html)
  71 {
  72     // Get encoding specified in HTML header.
  73     preg_match('#<meta .*charset=["\']?([^";\'>/]+)["\']? */?>#Usi', $html, $enc);
  74     if (!empty($enc[1])) {
  75         return strtolower($enc[1]);
  76     }
  77
  78     return false;
  79 }