MyShaarli/application/HttpUtils.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

167 lines
5 KiB
PHP
Executable file

<?php
/**
* GET an HTTP URL to retrieve its content
*
* @param string $url URL to get (http://...)
* @param int $timeout network timeout (in seconds)
* @param int $maxBytes maximum downloaded bytes (default: 4 MiB)
*
* @return array HTTP response headers, downloaded content
*
* Output format:
* [0] = associative array containing HTTP response headers
* [1] = URL content (downloaded data)
*
* Example:
* list($headers, $data) = get_http_response('http://sebauvage.net/');
* if (strpos($headers[0], '200 OK') !== false) {
* echo 'Data type: '.htmlspecialchars($headers['Content-Type']);
* } else {
* echo 'There was an error: '.htmlspecialchars($headers[0]);
* }
*
* @see http://php.net/manual/en/function.file-get-contents.php
* @see http://php.net/manual/en/function.stream-context-create.php
* @see http://php.net/manual/en/function.get-headers.php
*/
function get_http_response($url, $timeout = 30, $maxBytes = 4194304)
{
$urlObj = new Url($url);
if (! filter_var($url, FILTER_VALIDATE_URL) || ! $urlObj->isHttp()) {
return array(array(0 => 'Invalid HTTP Url'), false);
}
$options = array(
'http' => array(
'method' => 'GET',
'timeout' => $timeout,
'user_agent' => 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:23.0)'
.' Gecko/20100101 Firefox/23.0',
'request_fulluri' => true,
)
);
$context = stream_context_create($options);
stream_context_set_default($options);
list($headers, $finalUrl) = get_redirected_headers($urlObj->cleanup());
if (! $headers || strpos($headers[0], '200 OK') === false) {
return array($headers, false);
}
try {
// TODO: catch Exception in calling code (thumbnailer)
$content = file_get_contents($finalUrl, false, $context, -1, $maxBytes);
} catch (Exception $exc) {
return array(array(0 => 'HTTP Error'), $exc->getMessage());
}
return array($headers, $content);
}
/**
* Retrieve HTTP headers, following n redirections (temporary and permanent).
*
* @param string $url initial URL to reach.
* @param int $redirectionLimit max redirection follow..
*
* @return array
*/
function get_redirected_headers($url, $redirectionLimit = 3)
{
$headers = get_headers($url, 1);
// Headers found, redirection found, and limit not reached.
if ($redirectionLimit-- > 0
&& !empty($headers)
&& (strpos($headers[0], '301') !== false || strpos($headers[0], '302') !== false)
&& !empty($headers['Location'])) {
$redirection = is_array($headers['Location']) ? end($headers['Location']) : $headers['Location'];
if ($redirection != $url) {
return get_redirected_headers($redirection, $redirectionLimit);
}
}
return array($headers, $url);
}
/**
* Returns the server's base URL: scheme://domain.tld[:port]
*
* @param array $server the $_SERVER array
*
* @return string the server's base URL
*
* @see http://www.ietf.org/rfc/rfc7239.txt
* @see http://www.ietf.org/rfc/rfc6648.txt
* @see http://stackoverflow.com/a/3561399
* @see http://stackoverflow.com/q/452375
*/
function server_url($server)
{
$scheme = 'http';
$port = '';
// Shaarli is served behind a proxy
if (isset($server['HTTP_X_FORWARDED_PROTO'])) {
// Keep forwarded scheme
$scheme = $server['HTTP_X_FORWARDED_PROTO'];
if (isset($server['HTTP_X_FORWARDED_PORT'])) {
// Keep forwarded port
$port = ':'.$server['HTTP_X_FORWARDED_PORT'];
}
return $scheme.'://'.$server['SERVER_NAME'].$port;
}
// SSL detection
if ((! empty($server['HTTPS']) && strtolower($server['HTTPS']) == 'on')
|| (isset($server['SERVER_PORT']) && $server['SERVER_PORT'] == '443')) {
$scheme = 'https';
}
// Do not append standard port values
if (($scheme == 'http' && $server['SERVER_PORT'] != '80')
|| ($scheme == 'https' && $server['SERVER_PORT'] != '443')) {
$port = ':'.$server['SERVER_PORT'];
}
return $scheme.'://'.$server['SERVER_NAME'].$port;
}
/**
* Returns the absolute URL of the current script, without the query
*
* If the resource is "index.php", then it is removed (for better-looking URLs)
*
* @param array $server the $_SERVER array
*
* @return string the absolute URL of the current script, without the query
*/
function index_url($server)
{
$scriptname = $server['SCRIPT_NAME'];
if (endswith($scriptname, 'index.php')) {
$scriptname = substr($scriptname, 0, -9);
}
return server_url($server) . $scriptname;
}
/**
* Returns the absolute URL of the current script, with the query
*
* If the resource is "index.php", then it is removed (for better-looking URLs)
*
* @param array $server the $_SERVER array
*
* @return string the absolute URL of the current script, with the query
*/
function page_url($server)
{
if (! empty($server['QUERY_STRING'])) {
return index_url($server).'?'.$server['QUERY_STRING'];
}
return index_url($server);
}