WordPress/wp-includes/class-wp-shutdown-handler.php

197 lines
5.7 KiB
PHP

<?php
/**
* Error Protection API: WP_Shutdown_Handler class
*
* @package WordPress
* @since 5.1.0
*/
/**
* Core class used as the default shutdown handler.
*
* A drop-in 'shutdown-handler.php' can be used to override the instance of this class and use a custom implementation
* for the shutdown handler that WordPress registers. The custom class should extend this class and can override its
* methods individually as necessary. The file must return the instance of the class that should be registered.
*
* @since 5.1.0
*/
class WP_Shutdown_Handler {
/**
* Runs the shutdown handler.
*
* This method is registered via `register_shutdown_function()`.
*
* @since 5.1.0
*/
public function handle() {
// Bail if WordPress executed successfully.
if ( defined( 'WP_EXECUTION_SUCCEEDED' ) && WP_EXECUTION_SUCCEEDED ) {
return;
}
try {
// Bail if no error found.
$error = $this->detect_error();
if ( ! $error ) {
return;
}
// If the error was stored and thus the extension paused,
// redirect the request to catch multiple errors in one go.
if ( $this->store_error( $error ) ) {
$this->redirect_protected();
}
// Display the PHP error template.
$this->display_error_template();
} catch ( Exception $e ) {
// Catch exceptions and remain silent.
}
}
/**
* Detects the error causing the crash if it should be handled.
*
* @since 5.1.0
*
* @return array|null Error that was triggered, or null if no error received or if the error should not be handled.
*/
protected function detect_error() {
$error = error_get_last();
// No error, just skip the error handling code.
if ( null === $error ) {
return null;
}
// Bail if this error should not be handled.
if ( ! wp_should_handle_error( $error ) ) {
return null;
}
return $error;
}
/**
* Stores the given error so that the extension causing it is paused.
*
* @since 5.1.0
*
* @param array $error Error that was triggered.
* @return bool True if the error was stored successfully, false otherwise.
*/
protected function store_error( $error ) {
// Do not pause extensions if they only crash on a non-protected endpoint.
if ( ! is_protected_endpoint() ) {
return false;
}
return wp_record_extension_error( $error );
}
/**
* Redirects the current request to allow recovering multiple errors in one go.
*
* The redirection will only happen when on a protected endpoint.
*
* It must be ensured that this method is only called when an error actually occurred and will not occur on the
* next request again. Otherwise it will create a redirect loop.
*
* @since 5.1.0
*/
protected function redirect_protected() {
// Do not redirect requests on non-protected endpoints.
if ( ! is_protected_endpoint() ) {
return;
}
// Pluggable is usually loaded after plugins, so we manually include it here for redirection functionality.
if ( ! function_exists( 'wp_redirect' ) ) {
include ABSPATH . WPINC . '/pluggable.php';
}
$scheme = is_ssl() ? 'https://' : 'http://';
$url = "{$scheme}{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";
wp_redirect( $url );
exit;
}
/**
* Displays the PHP error template and sends the HTTP status code, typically 500.
*
* A drop-in 'php-error.php' can be used as a custom template. This drop-in should control the HTTP status code and
* print the HTML markup indicating that a PHP error occurred. Note that this drop-in may potentially be executed
* very early in the WordPress bootstrap process, so any core functions used that are not part of
* `wp-includes/load.php` should be checked for before being called.
*
* If no such drop-in is available, this will call {@see WP_Shutdown_Handler::display_default_error_template()}.
*
* @since 5.1.0
*/
protected function display_error_template() {
if ( defined( 'WP_CONTENT_DIR' ) ) {
// Load custom PHP error template, if present.
$php_error_pluggable = WP_CONTENT_DIR . '/php-error.php';
if ( is_readable( $php_error_pluggable ) ) {
require_once $php_error_pluggable;
die();
}
}
// Otherwise, display the default error template.
$this->display_default_error_template();
}
/**
* Displays the default PHP error template.
*
* This method is called conditionally if no 'php-error.php' drop-in is available.
*
* It calls {@see wp_die()} with a message indicating that the site is experiencing technical difficulties and a
* login link to the admin backend. The {@see 'wp_php_error_message'} and {@see 'wp_php_error_args'} filters can
* be used to modify these parameters.
*
* @since 5.1.0
*/
protected function display_default_error_template() {
if ( ! function_exists( '__' ) ) {
wp_load_translations_early();
}
if ( ! function_exists( 'wp_die' ) ) {
require_once ABSPATH . WPINC . '/functions.php';
}
$message = __( 'The site is experiencing technical difficulties.' );
$args = array( 'response' => 500 );
if ( function_exists( 'admin_url' ) ) {
$args['link_url'] = admin_url();
$args['link_text'] = __( 'Log into the admin backend to fix this.' );
}
/**
* Filters the message that the default PHP error template displays.
*
* @since 5.1.0
*
* @param string $message HTML error message to display.
*/
$message = apply_filters( 'wp_php_error_message', $message );
/**
* Filters the arguments passed to {@see wp_die()} for the default PHP error template.
*
* @since 5.1.0
*
* @param array $args Associative array of arguments passed to `wp_die()`. By default these contain a
* 'response' key, and optionally 'link_url' and 'link_text' keys.
*/
$args = apply_filters( 'wp_php_error_args', $args );
wp_die( $message, '', $args );
}
}