MyShaarli/application/LinkUtils.php
ArthurHoaro 1557cefbd7 Fixes #410 - Retrieve title fails in multiple cases
* `get_http_url()` renamed to `get_http_response()`.
  * Use the same HTTP context to retrieve response headers and content.
  * Follow HTTP 301 and 302 redirections to retrieve the title (default max 3 redirections).
  * Add `LinkUtils` to extract titles and charset.
  * Try to retrieve charset from HTTP headers first (new), then HTML content.
  * Use mb_string to re-encode title if necessary.
2016-01-11 21:19:31 +01:00

79 lines
2 KiB
PHP
Executable file

<?php
/**
* Extract title from an HTML document.
*
* @param string $html HTML content where to look for a title.
*
* @return bool|string Extracted title if found, false otherwise.
*/
function html_extract_title($html)
{
if (preg_match('!<title>(.*)</title>!is', $html, $matches)) {
return trim(str_replace("\n", ' ', $matches[1]));
}
return false;
}
/**
* Determine charset from downloaded page.
* Priority:
* 1. HTTP headers (Content type).
* 2. HTML content page (tag <meta charset>).
* 3. Use a default charset (default: UTF-8).
*
* @param array $headers HTTP headers array.
* @param string $htmlContent HTML content where to look for charset.
* @param string $defaultCharset Default charset to apply if other methods failed.
*
* @return string Determined charset.
*/
function get_charset($headers, $htmlContent, $defaultCharset = 'utf-8')
{
if ($charset = headers_extract_charset($headers)) {
return $charset;
}
if ($charset = html_extract_charset($htmlContent)) {
return $charset;
}
return $defaultCharset;
}
/**
* Extract charset from HTTP headers if it's defined.
*
* @param array $headers HTTP headers array.
*
* @return bool|string Charset string if found (lowercase), false otherwise.
*/
function headers_extract_charset($headers)
{
if (! empty($headers['Content-Type']) && strpos($headers['Content-Type'], 'charset=') !== false) {
preg_match('/charset="?([^; ]+)/i', $headers['Content-Type'], $match);
if (! empty($match[1])) {
return strtolower(trim($match[1]));
}
}
return false;
}
/**
* Extract charset HTML content (tag <meta charset>).
*
* @param string $html HTML content where to look for charset.
*
* @return bool|string Charset string if found, false otherwise.
*/
function html_extract_charset($html)
{
// Get encoding specified in HTML header.
preg_match('#<meta .*charset="?([^">/]+)"? */?>#Usi', $html, $enc);
if (!empty($enc[1])) {
return strtolower($enc[1]);
}
return false;
}