Creates a web-accessible URL for a stream to an external or local file.
Compatibility: normal paths and stream wrappers.
There are two kinds of local files:
$uri: The URI to a file for which we need an external URL, or the path to a shipped file.
A string containing a URL that may be used to access the file. If the provided string already contains a preceding 'http', 'https', or '/', nothing is done and the same string is returned. If a stream wrapper could not be found to generate an external URL, then FALSE is returned.
function file_create_url($uri) {
// Allow the URI to be altered, e.g. to serve a file from a CDN or static
// file server.
drupal_alter('file_url', $uri);
$scheme = file_uri_scheme($uri);
if (!$scheme) {
// Allow for:
// - root-relative URIs (e.g. /foo.jpg in http://example.com/foo.jpg)
// - protocol-relative URIs (e.g. //bar.jpg, which is expanded to
// http://example.com/bar.jpg by the browser when viewing a page over
// HTTP and to https://example.com/bar.jpg when viewing a HTTPS page)
// Both types of relative URIs are characterized by a leading slash, hence
// we can use a single check.
if (drupal_substr($uri, 0, 1) == '/') {
return $uri;
}
else {
// If this is not a properly formatted stream, then it is a shipped file.
// Therefore, return the urlencoded URI with the base URL prepended.
return $GLOBALS['base_url'] . '/' . drupal_encode_path($uri);
}
}
elseif ($scheme == 'http' || $scheme == 'https') {
// Check for HTTP so that we don't have to implement getExternalUrl() for
// the HTTP wrapper.
return $uri;
}
else {
// Attempt to return an external URL using the appropriate wrapper.
if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
return $wrapper
->getExternalUrl();
}
else {
return FALSE;
}
}
}