As the sun rises and the forest mist clears, and the clouds return and the caves darken, these changes of light and shadow are the morning and evening in the mountains. Wildflowers bloom with their subtle fragrance, fine trees flourish with their dense shade, the wind and frost are pure and clean, and the water recedes to reveal the rocks—these are the four seasons in the mountains. Going out in the morning and returning in the evening, the scenery of the four seasons is different, and the joy is endless.至于负者歌于途,行者休于树,前者呼,后者应,伛偻提携,往来而不绝者,滁人游也。临溪而渔,溪深而鱼肥,酿泉为酒,泉香而酒洌,山肴野蔌,杂然而前陈者,太守宴也。宴酣之乐,非丝非竹,射者中,弈者胜,觥筹交错,起坐而喧哗者,众宾欢也。苍颜白发,颓然乎其间者,太守醉也。
<?php
/**
* WPSEO plugin file.
*
* @package WPSEO\Admin
*/
/**
* Loads the MyYoast proxy.
*
* This class registers a proxy page on `admin.php`. Which is reached with the `page=PAGE_IDENTIFIER` parameter.
* It will read external files and serves them like they are located locally.
*/
class WPSEO_MyYoast_Proxy implements WPSEO_WordPress_Integration {
/**
* The page identifier used in WordPress to register the MyYoast proxy page.
*
* @var string
*/
public const PAGE_IDENTIFIER = 'wpseo_myyoast_proxy';
/**
* The cache control's max age. Used in the header of a successful proxy response.
*
* @var int
*/
public const CACHE_CONTROL_MAX_AGE = DAY_IN_SECONDS;
/**
* Registers the hooks when the user is on the right page.
*
* @codeCoverageIgnore
*
* @return void
*/
public function register_hooks() {
if ( ! $this->is_proxy_page() ) {
return;
}
// Register the page for the proxy.
add_action( 'admin_menu', [ $this, 'add_proxy_page' ] );
add_action( 'admin_init', [ $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 === [] ) {
// 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 );
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.
*
* @return string The body of the response.
*
* @throws Exception When `wp_remote_get` returned an error.
* @throws Exception When the response code is not 200.
*/
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 );
}
/**
* Determines the proxy options based on the file and plugin version arguments.
*
* When the file is known it returns an array like this:
* <code>
* $array = array(
* 'content_type' => 'the content type'
* 'url' => 'the url, possibly with the plugin version'
* )
* </code>
*
* @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 [
'content_type' => 'text/javascript; charset=UTF-8',
'url' => 'https://my.yoast.com/api/downloads/file/analysis-worker?plugin_version=' . $this->get_plugin_version(),
];
}
return [];
}
/**
* 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() {
// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Reason: We are not processing form information.
$page = isset( $_GET['page'] ) && is_string( $_GET['page'] ) ? sanitize_text_field( wp_unslash( $_GET['page'] ) ) : '';
return $page === self::PAGE_IDENTIFIER;
}
/**
* Returns the proxy file from the HTTP request parameters.
*
* @codeCoverageIgnore
*
* @return string The sanitized file request parameter or an empty string if it does not exist.
*/
protected function get_proxy_file() {
// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Reason: We are not processing form information.
if ( isset( $_GET['file'] ) && is_string( $_GET['file'] ) ) {
// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Reason: We are not processing form information.
return sanitize_text_field( wp_unslash( $_GET['file'] ) );
}
return '';
}
/**
* Returns the plugin version from the HTTP request parameters.
*
* @codeCoverageIgnore
*
* @return string The sanitized plugin_version request parameter or an empty string if it does not exist.
*/
protected function get_plugin_version() {
// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Reason: We are not processing form information.
if ( isset( $_GET['plugin_version'] ) && is_string( $_GET['plugin_version'] ) ) {
// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Reason: We are not processing form information.
$plugin_version = sanitize_text_field( wp_unslash( $_GET['plugin_version'] ) );
// Replace slashes to secure against requiring a file from another path.
return str_replace( [ '/', '\\' ], '_', $plugin_version );
}
return '';
}
/**
* 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 );
}
}