is_proxy_page() ) { return; } // Register the page for the proxy. add_action( 'admin_menu', array( $this, 'add_proxy_page' ) ); add_action( 'admin_init', array( $this, 'handle_proxy_page' ) ); } /** * Registers the proxy page. It does not actually add a link to the dashboard. * * @codeCoverageIgnore * * @return void */ public function add_proxy_page() { add_dashboard_page( '', '', 'read', self::PAGE_IDENTIFIER, '' ); } /** * Renders the requested proxy page and exits to prevent the WordPress UI from loading. * * @codeCoverageIgnore * * @return void */ public function handle_proxy_page() { $this->render_proxy_page(); // Prevent the WordPress UI from loading. exit; } /** * Renders the requested proxy page. * * This is separated from the exits to be able to test it. * * @return void */ public function render_proxy_page() { $proxy_options = $this->determine_proxy_options(); if ( $proxy_options === array() ) { // Do not accept any other file than implemented. $this->set_header( 'HTTP/1.0 501 Requested file not implemented' ); return; } // Set the headers before serving the remote file. $this->set_header( 'Content-Type: ' . $proxy_options['content_type'] ); $this->set_header( 'Cache-Control: max-age=' . self::CACHE_CONTROL_MAX_AGE ); if ( $this->should_load_url_directly() ) { /* * If an error occurred, fallback to the next proxy method (`wp_remote_get`). * Otherwise, we are done here. */ if ( $this->load_url( $proxy_options['url'] ) ) { return; } } try { echo $this->get_remote_url_body( $proxy_options['url'] ); } catch ( Exception $e ) { /* * Reset the file headers because the loading failed. * * Note: Due to supporting PHP 5.2 `header_remove` can not be used here. * Overwrite the headers instead. */ $this->set_header( 'Content-Type: text/plain' ); $this->set_header( 'Cache-Control: max-age=0' ); $this->set_header( 'HTTP/1.0 500 ' . $e->getMessage() ); } } /** * Tries to load the given url via `wp_remote_get`. * * @codeCoverageIgnore * * @param string $url The url to load. * * @throws Exception When `wp_remote_get` returned an error. * @throws Exception When the response code is not 200. * * @return string The body of the response. */ protected function get_remote_url_body( $url ) { $response = wp_remote_get( $url ); if ( $response instanceof WP_Error ) { throw new Exception( 'Unable to retrieve file from MyYoast' ); } if ( wp_remote_retrieve_response_code( $response ) !== 200 ) { throw new Exception( 'Received unexpected response from MyYoast' ); } return wp_remote_retrieve_body( $response ); } /** * Tries to load the given url. * * @link https://php.net/manual/en/function.readfile.php * * @codeCoverageIgnore * * @param string $url The url to load. * * @return bool False if an error occurred. */ protected function load_url( $url ) { return readfile( $url ) !== false; } /** * Determines the proxy options based on the file and plugin version arguments. * * When the file is known it returns an array like this: * * $array = array( * 'content_type' => 'the content type' * 'url' => 'the url, possibly with the plugin version' * ) * * * @return array Empty for an unknown file. See format above for known files. */ protected function determine_proxy_options() { if ( $this->get_proxy_file() === 'research-webworker' ) { return array( 'content_type' => 'text/javascript; charset=UTF-8', 'url' => 'https://my.yoast.com/api/downloads/file/analysis-worker?plugin_version=' . $this->get_plugin_version(), ); } return array(); } /** * Checks the PHP configuration of allow_url_fopen. * * @codeCoverageIgnore * * @link https://php.net/manual/en/filesystem.configuration.php#ini.allow-url-fopen * * @return bool True when the PHP configuration allows for url loading via readfile. */ protected function should_load_url_directly() { return ! ! ini_get( 'allow_url_fopen' ); } /** * Checks if the current page is the MyYoast proxy page. * * @codeCoverageIgnore * * @return bool True when the page request parameter equals the proxy page. */ protected function is_proxy_page() { return filter_input( INPUT_GET, 'page' ) === self::PAGE_IDENTIFIER; } /** * Returns the proxy file from the HTTP request parameters. * * @codeCoverageIgnore * * @return string The sanitized file request parameter. */ protected function get_proxy_file() { return filter_input( INPUT_GET, 'file', FILTER_SANITIZE_STRING ); } /** * Returns the plugin version from the HTTP request parameters. * * @codeCoverageIgnore * * @return string The sanitized plugin_version request parameter. */ protected function get_plugin_version() { $plugin_version = filter_input( INPUT_GET, 'plugin_version', FILTER_SANITIZE_STRING ); // Replace slashes to secure against requiring a file from another path. $plugin_version = str_replace( array( '/', '\\' ), '_', $plugin_version ); return $plugin_version; } /** * Sets the HTTP header. * * This is a tiny helper function to enable better testing. * * @codeCoverageIgnore * * @param string $header The header to set. * * @return void */ protected function set_header( $header ) { header( $header ); } }