/**
* Handles the sending of file data to the user's browser, including support for
* byteranges etc.
*
* @category files
* @global stdClass $CFG
* @global stdClass $COURSE
* @global moodle_session $SESSION
* @param stored_file $stored_file local file object
* @param int $lifetime Number of seconds before the file should expire from caches (default 24 hours)
* @param int $filter 0 (default)=no filtering, 1=all files, 2=html files only
* @param bool $forcedownload If true (default false), forces download of file rather than view in browser/plugin
* @param string $filename Override filename
* @param bool $dontdie - return control to caller afterwards. this is not recommended and only used for cleanup tasks.
* if this is passed as true, ignore_user_abort is called. if you don't want your processing to continue on cancel,
* you must detect this case when control is returned using connection_aborted. Please not that session is closed
* and should not be reopened.
* @return null script execution stopped unless $dontdie is true
*/
function send_stored_file($stored_file, $lifetime = 86400, $filter = 0, $forcedownload = false, $filename = null, $dontdie = false)
{
global $CFG, $COURSE, $SESSION;
if (!$stored_file or $stored_file->is_directory()) {
// nothing to serve
if ($dontdie) {
return;
}
die;
}
if ($dontdie) {
ignore_user_abort(true);
}
session_get_instance()->write_close();
// unlock session during fileserving
// Use given MIME type if specified, otherwise guess it using mimeinfo.
// IE, Konqueror and Opera open html file directly in browser from web even when directed to save it to disk :-O
// only Firefox saves all files locally before opening when content-disposition: attachment stated
$filename = is_null($filename) ? $stored_file->get_filename() : $filename;
$isFF = check_browser_version('Firefox', '1.5');
// only FF > 1.5 properly tested
$mimetype = ($forcedownload and !$isFF) ? 'application/x-forcedownload' : ($stored_file->get_mimetype() ? $stored_file->get_mimetype() : mimeinfo('type', $filename));
$lastmodified = $stored_file->get_timemodified();
$filesize = $stored_file->get_filesize();
if ($lifetime > 0 && !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
// get unixtime of request header; clip extra junk off first
$since = strtotime(preg_replace('/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"]));
if ($since && $since >= $lastmodified) {
header('HTTP/1.1 304 Not Modified');
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + $lifetime) . ' GMT');
header('Cache-Control: max-age=' . $lifetime);
header('Content-Type: ' . $mimetype);
if ($dontdie) {
return;
}
die;
}
}
//do not put '@' before the next header to detect incorrect moodle configurations,
//error should be better than "weird" empty lines for admins/users
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $lastmodified) . ' GMT');
// if user is using IE, urlencode the filename so that multibyte file name will show up correctly on popup
if (check_browser_version('MSIE')) {
$filename = rawurlencode($filename);
}
if ($forcedownload) {
header('Content-Disposition: attachment; filename="' . $filename . '"');
} else {
header('Content-Disposition: inline; filename="' . $filename . '"');
}
if ($lifetime > 0) {
header('Cache-Control: max-age=' . $lifetime);
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + $lifetime) . ' GMT');
header('Pragma: ');
if (empty($CFG->disablebyteserving) && $mimetype != 'text/plain' && $mimetype != 'text/html') {
header('Accept-Ranges: bytes');
if (!empty($_SERVER['HTTP_RANGE']) && strpos($_SERVER['HTTP_RANGE'], 'bytes=') !== FALSE) {
// byteserving stuff - for acrobat reader and download accelerators
// see: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35
// inspired by: http://www.coneural.org/florian/papers/04_byteserving.php
$ranges = false;
if (preg_match_all('/(\\d*)-(\\d*)/', $_SERVER['HTTP_RANGE'], $ranges, PREG_SET_ORDER)) {
foreach ($ranges as $key => $value) {
if ($ranges[$key][1] == '') {
//suffix case
$ranges[$key][1] = $filesize - $ranges[$key][2];
$ranges[$key][2] = $filesize - 1;
} else {
if ($ranges[$key][2] == '' || $ranges[$key][2] > $filesize - 1) {
//fix range length
$ranges[$key][2] = $filesize - 1;
}
}
if ($ranges[$key][2] != '' && $ranges[$key][2] < $ranges[$key][1]) {
//invalid byte-range ==> ignore header
$ranges = false;
break;
}
//prepare multipart header
$ranges[$key][0] = "\r\n--" . BYTESERVING_BOUNDARY . "\r\nContent-Type: {$mimetype}\r\n";
$ranges[$key][0] .= "Content-Range: bytes {$ranges[$key][1]}-{$ranges[$key][2]}/{$filesize}\r\n\r\n";
}
} else {
$ranges = false;
}
if ($ranges) {
byteserving_send_file($stored_file->get_content_file_handle(), $mimetype, $ranges, $filesize);
}
}
} else {
/// Do not byteserve (disabled, strings, text and html files).
header('Accept-Ranges: none');
}
} else {
// Do not cache files in proxies and browsers
if (strpos($CFG->wwwroot, 'https://') === 0) {
//https sites - watch out for IE! KB812935 and KB316431
header('Cache-Control: max-age=10');
header('Expires: ' . gmdate('D, d M Y H:i:s', 0) . ' GMT');
header('Pragma: ');
} else {
//normal http - prevent caching at all cost
header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
header('Expires: ' . gmdate('D, d M Y H:i:s', 0) . ' GMT');
header('Pragma: no-cache');
}
header('Accept-Ranges: none');
// Do not allow byteserving when caching disabled
}
if (empty($filter)) {
if ($mimetype == 'text/plain') {
header('Content-Type: Text/plain; charset=utf-8');
//add encoding
} else {
header('Content-Type: ' . $mimetype);
}
header('Content-Length: ' . $filesize);
//flush the buffers - save memory and disable sid rewrite
//this also disables zlib compression
prepare_file_content_sending();
// send the contents
$stored_file->readfile();
} else {
// Try to put the file through filters
if ($mimetype == 'text/html') {
$options = new stdClass();
$options->noclean = true;
$options->nocache = true;
// temporary workaround for MDL-5136
$text = $stored_file->get_content();
$text = file_modify_html_header($text);
$output = format_text($text, FORMAT_HTML, $options, $COURSE->id);
header('Content-Length: ' . strlen($output));
header('Content-Type: text/html');
//flush the buffers - save memory and disable sid rewrite
//this also disables zlib compression
prepare_file_content_sending();
// send the contents
echo $output;
} else {
if ($mimetype == 'text/plain' and $filter == 1) {
// only filter text if filter all files is selected
$options = new stdClass();
$options->newlines = false;
$options->noclean = true;
$text = $stored_file->get_content();
$output = '<pre>' . format_text($text, FORMAT_MOODLE, $options, $COURSE->id) . '</pre>';
header('Content-Length: ' . strlen($output));
header('Content-Type: text/html; charset=utf-8');
//add encoding
//flush the buffers - save memory and disable sid rewrite
//this also disables zlib compression
prepare_file_content_sending();
// send the contents
echo $output;
} else {
// Just send it out raw
header('Content-Length: ' . $filesize);
header('Content-Type: ' . $mimetype);
//flush the buffers - save memory and disable sid rewrite
//this also disables zlib compression
prepare_file_content_sending();
// send the contents
$stored_file->readfile();
}
}
}
if ($dontdie) {
return;
}
die;
//no more chars to output!!!
}
