wordpress常见优化教程，后台优化代码

// Disable core auto-updates
add_filter( 'auto_update_core', '__return_false' );
// Disable auto-updates for plugins.
add_filter( 'auto_update_plugin', '__return_false' );
// Disable auto-updates for themes.
add_filter( 'auto_update_theme', '__return_false' );

// Disable auto-update emails.
add_filter( 'auto_core_update_send_email', '__return_false' );

// Disable auto-update emails for plugins.
add_filter( 'auto_plugin_update_send_email', '__return_false' );

// Disable auto-update emails for themes.
add_filter( 'auto_theme_update_send_email', '__return_false' );

add_filter( 'comment_form_default_fields', function ($fields) {
	if ( isset( $fields['url'] ) ) {
		unset( $fields['url'] );
	}

	return $fields;
}, 150 );

/**
 * Disable all embeds in WordPress.
 */
add_action( 'init', function () {

	// Remove the REST API endpoint.
	remove_action( 'rest_api_init', 'wp_oembed_register_route' );

	// Turn off oEmbed auto discovery.
	add_filter( 'embed_oembed_discover', '__return_false' );

	// Don't filter oEmbed results.
	remove_filter( 'oembed_dataparse', 'wp_filter_oembed_result', 10 );

	// Remove oEmbed discovery links.
	remove_action( 'wp_head', 'wp_oembed_add_discovery_links' );

	// Remove oEmbed-specific JavaScript from the front-end and back-end.
	remove_action( 'wp_head', 'wp_oembed_add_host_js' );
	add_filter( 'tiny_mce_plugins', function ( $plugins ) {
		return array_diff( $plugins, array( 'wpembed' ) );
	} );

	// Remove all embeds rewrite rules.
	add_filter( 'rewrite_rules_array', function ( $rules ) {
		foreach ( $rules as $rule => $rewrite ) {
			if ( false !== strpos( $rewrite, 'embed=true' ) ) {
				unset( $rules[ $rule ] );
			}
		}

		return $rules;
	} );

	// Remove filter of the oEmbed result before any HTTP requests are made.
	remove_filter( 'pre_oembed_result', 'wp_filter_pre_oembed_result', 10 );
}, 9999 );

	add_filter( 'wp_resource_hints', function ( $urls, $relation_type ) {
		if ( 'dns-prefetch' === $relation_type ) {
			$emoji_svg_url = apply_filters( 'emoji_svg_url', 'https://s.w.org/images/core/emoji/2/svg/' );
			$urls          = array_diff( $urls, array( $emoji_svg_url ) );
		}

		return $urls;
	}, 10, 2 );
} );

add_action(
	'enqueue_block_editor_assets',
	function () {
		$script = "jQuery( window ).load(function() { const isFullscreenMode = wp.data.select( 'core/edit-post' ).isFeatureActive( 'fullscreenMode' ); if ( isFullscreenMode ) { wp.data.dispatch( 'core/edit-post' ).toggleFeature( 'fullscreenMode' ); } });";
		wp_add_inline_script( 'wp-blocks', $script );
	}
);

add_filter( 'block_editor_settings_all', function ( $settings ) {
	
	$settings['codeEditingEnabled'] = current_user_can( 'manage_options' );

	return $settings;
} );

add_filter( 'wp_lazy_loading_enabled', '__return_false' );

add_filter( 'enable_login_autofocus', '__return_false' );

function wpcode_send_new_user_notifications( $user_id, $notify = 'user' ) {
	if ( empty( $notify ) || 'admin' === $notify ) {
		return;
	} elseif ( 'both' === $notify ) {
		// Send new users the email but not the admin.
		$notify = 'user';
	}
	wp_send_new_user_notifications( $user_id, $notify );
}

add_action(
	'init',
	function () {
		// Disable default email notifications.
		remove_action( 'register_new_user', 'wp_send_new_user_notifications' );
		remove_action( 'edit_user_created_user', 'wp_send_new_user_notifications' );

		// Replace with custom function that only sends to user.
		add_action( 'register_new_user', 'wpcode_send_new_user_notifications' );
		add_action( 'edit_user_created_user', 'wpcode_send_new_user_notifications', 10, 2 );
	}
);

remove_action( 'xmlrpc_rsd_apis', 'rest_output_rsd' );
remove_action( 'wp_head', 'rest_output_link_wp_head' );
remove_action( 'template_redirect', 'rest_output_link_header', 11 );

// Prevent search queries.
add_action(
	'parse_query',
	function ( $query, $error = true ) {
		if ( is_search() && ! is_admin() ) {
			$query->is_search       = false;
			$query->query_vars['s'] = false;
			$query->query['s']      = false;
			if ( true === $error ) {
				$query->is_404 = true;
			}
		}
	},
	15,
	2
);

// Remove the Search Widget.
add_action(
	'widgets_init',
	function () {
		unregister_widget( 'WP_Widget_Search' );
	}
);

// Remove the search form.
add_filter( 'get_search_form', '__return_empty_string', 999 );

// Remove the core search block.
add_action(
	'init',
	function () {
		if ( ! function_exists( 'unregister_block_type' ) || ! class_exists( 'WP_Block_Type_Registry' ) ) {
			return;
		}
		$block = 'core/search';
		if ( WP_Block_Type_Registry::get_instance()->is_registered( $block ) ) {
			unregister_block_type( $block );
		}
	}
);

// Remove admin bar menu search box.
add_action(
	'admin_bar_menu',
	function ( $wp_admin_bar ) {
		$wp_admin_bar->remove_menu( 'search' );
	},
	11
);

add_action( 'pre_ping', function( &$links ) {
	$home = get_option( 'home' );
	foreach ( $links as $l => $link ) {
		if ( 0 === strpos( $link, $home ) ) {
			unset( $links[ $l ] );
		}
	}
} );

// Remove Tools Submenu Item for Site Health.
add_action( 'admin_menu', function () {
	remove_submenu_page( 'tools.php', 'site-health.php' );
} );

// Prevent direct access to the Site Health page.
add_action( 'current_screen', function () {
	$screen = get_current_screen();
	if ( 'site-health' === $screen->id ) {
		wp_safe_redirect( admin_url() );
		exit;
	}
} );

// Disable the Site Health Dashboard Widget.
add_action( 'wp_dashboard_setup', function () {
	global $wp_meta_boxes;
	if ( isset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_site_health'] ) ) {
		unset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_site_health'] );
	}
} );

remove_action('wp_head', 'wp_shortlink_wp_head' );

add_action( 'admin_head', function () {
	if ( current_user_can( 'update_core' ) ) {
		return;
	}
	remove_action( 'admin_notices', 'update_nag', 3 );
}, 1 );

remove_action('wp_head', 'wlwmanifest_link');

add_filter(
	'rest_authentication_errors',
	function ( $access ) {
		return new WP_Error(
			'rest_disabled',
			__( 'The WordPress REST API has been disabled.' ),
			array(
				'status' => rest_authorization_required_code(),
			)
		);
	}
);

add_filter('wp_sitemaps_enabled', '__return_false');

add_filter( 'xmlrpc_enabled', '__return_false' );

add_action( 'login_footer', function () {
	remove_action( 'login_footer', 'wp_shake_js', 12 );
} );

function wpcode_snippet_remove_query_strings_split( $src ) {
	$output = preg_split( "/(&ver|\\?ver)/", $src );

	return $output ? $output[0] : '';
}

add_action( 'init', function () {
	if ( ! is_admin() ) {
		add_filter( 'script_loader_src', 'wpcode_snippet_remove_query_strings_split', 15 );
		add_filter( 'style_loader_src', 'wpcode_snippet_remove_query_strings_split', 15 );
	}
} );

add_action( 'wp_before_admin_bar_render', function () {
	global $wp_admin_bar;
	$wp_admin_bar->remove_menu( 'wp-logo' );
}, 0 );

add_filter('the_generator', '__return_empty_string');

add_action( 'wp_enqueue_scripts', function() {
	wp_dequeue_style( 'wp-block-library' );
	wp_dequeue_style( 'wp-block-library-theme' );
}, 110 );