/**
* Downloads a resource identified by the parameters.
*
* If only the first parameter is passed, and it is an instance of a cache
* file, downloads the resource described by it.
* If it is a URL, the request timeout and target path will be computed by this instance.
* Otherwise, they will be overridden by the specified values, respectively.
*
* If the 'content-md5' header is present in the responce, MD5 checksum
* verification will take place.
*
* @since 4.7.3
* @see get_download_request_timeout()
* @see WPRSS_Image_Cache_Image::get_download_request_timeout()
* @see get_unique_filename()
* @see WPRSS_Image_Cache_Image::get_current_path()
* @see get_tmp_dir()
* @see wp_mkdir_p()
* @see wp_safe_remote_get()
* @see verify_file_md5()
* @param WPRSS_Image_Cache_Image|string $image An instance of a cache file, or the URL to download.
* @param int|null $request_timeout The timeout for the download request.
* @param string|null $target_path The relative path to the target file.
* @return string| The absolute local path to the downloaded file,
* or false if checksum verification failed.
* @throws Exception If the URL is invalid, or the destination path is not writable,
* or the file download library cannot be read, or any other error happens during download.
*/
public function download_image($image, $request_timeout = null, $target_path = null)
{
if ($image instanceof WPRSS_Image_Cache_Image) {
$url = $image->get_url();
$timeout = $image->get_download_request_timeout();
$path = $image->get_current_path();
} else {
$url = $image;
$timeout = $this->get_download_request_timeout();
$path = $this->get_unique_filename($url);
}
if (!$url) {
throw new Exception(sprintf(__('Invalid URL provided: "%1$s"'), $url));
}
if (!is_null($target_path)) {
$path = $target_path;
}
if (is_null($request_timeout)) {
$timeout = $request_timeout;
}
// Absolute path to the cache file
$tmpfname = $image instanceof WPRSS_Image_Cache_Image ? $image->get_tmp_dir($path) : $this->get_tmp_dir($path);
//WARNING: The file is not automatically deleted, The script must unlink() the file.
$dirname = dirname($tmpfname);
if (!wp_mkdir_p($dirname)) {
throw new Exception(sprintf(__('Could not create directory: "%1$s". Filename: "%2$s"'), $dirname, $tmpfname));
}
// Getting file download lib
$file_lib_path = ABSPATH . 'wp-admin/includes/file.php';
if (!is_readable($file_lib_path)) {
throw new Exception(sprintf(__('The file library cannot be read from %1$s'), $file_lib_path));
}
require_once $file_lib_path;
// Retrieving the remote resource
$response = wp_safe_remote_get($url, array('timeout' => $timeout, 'stream' => true, 'filename' => $tmpfname));
// Could not retrieve
if (is_wp_error($response)) {
@unlink($tmpfname);
throw new Exception($response->get_error_message());
}
// Retrieved, but remote server served error instead of resource
if (200 != wp_remote_retrieve_response_code($response)) {
@unlink($tmpfname);
throw new Exception(trim(wp_remote_retrieve_response_message($response)));
}
// Checksum verification
$content_md5 = wp_remote_retrieve_header($response, 'content-md5');
if ($content_md5) {
$md5_check = verify_file_md5($tmpfname, $content_md5);
if (is_wp_error($md5_check)) {
unlink($tmpfname);
return $md5_check;
}
}
return $tmpfname;
}
/**
* @since 4.6.10
* @param WPRSS_Image_Cache_Image $image
*/
protected function _prepare_image($image)
{
$image->set_download_request_timeout($this->get_download_request_timeout());
}
