wp/wp-includes/customize/class-wp-customize-selective-refresh.php
changeset 7 cf61fcea0001
child 9 177826044cd9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/customize/class-wp-customize-selective-refresh.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,456 @@
+<?php
+/**
+ * Customize API: WP_Customize_Selective_Refresh class
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 4.5.0
+ */
+
+/**
+ * Core Customizer class for implementing selective refresh.
+ *
+ * @since 4.5.0
+ */
+final class WP_Customize_Selective_Refresh {
+
+	/**
+	 * Query var used in requests to render partials.
+	 *
+	 * @since 4.5.0
+	 */
+	const RENDER_QUERY_VAR = 'wp_customize_render_partials';
+
+	/**
+	 * Customize manager.
+	 *
+	 * @since 4.5.0
+	 * @var WP_Customize_Manager
+	 */
+	public $manager;
+
+	/**
+	 * Registered instances of WP_Customize_Partial.
+	 *
+	 * @since 4.5.0
+	 * @var WP_Customize_Partial[]
+	 */
+	protected $partials = array();
+
+	/**
+	 * Log of errors triggered when partials are rendered.
+	 *
+	 * @since 4.5.0
+	 * @var array
+	 */
+	protected $triggered_errors = array();
+
+	/**
+	 * Keep track of the current partial being rendered.
+	 *
+	 * @since 4.5.0
+	 * @var string
+	 */
+	protected $current_partial_id;
+
+	/**
+	 * Plugin bootstrap for Partial Refresh functionality.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @param WP_Customize_Manager $manager Manager instance.
+	 */
+	public function __construct( WP_Customize_Manager $manager ) {
+		$this->manager = $manager;
+		require_once( ABSPATH . WPINC . '/customize/class-wp-customize-partial.php' );
+
+		add_action( 'customize_preview_init', array( $this, 'init_preview' ) );
+	}
+
+	/**
+	 * Retrieves the registered partials.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @return array Partials.
+	 */
+	public function partials() {
+		return $this->partials;
+	}
+
+	/**
+	 * Adds a partial.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @param WP_Customize_Partial|string $id   Customize Partial object, or Panel ID.
+	 * @param array                       $args {
+	 *  Optional. Array of properties for the new Partials object. Default empty array.
+	 *
+	 *  @type string   $type                  Type of the partial to be created.
+	 *  @type string   $selector              The jQuery selector to find the container element for the partial, that is, a partial's placement.
+	 *  @type array    $settings              IDs for settings tied to the partial.
+	 *  @type string   $primary_setting       The ID for the setting that this partial is primarily responsible for
+	 *                                        rendering. If not supplied, it will default to the ID of the first setting.
+	 *  @type string   $capability            Capability required to edit this partial.
+	 *                                        Normally this is empty and the capability is derived from the capabilities
+	 *                                        of the associated `$settings`.
+	 *  @type callable $render_callback       Render callback.
+	 *                                        Callback is called with one argument, the instance of WP_Customize_Partial.
+	 *                                        The callback can either echo the partial or return the partial as a string,
+	 *                                        or return false if error.
+	 *  @type bool     $container_inclusive   Whether the container element is included in the partial, or if only
+	 *                                        the contents are rendered.
+	 *  @type bool     $fallback_refresh      Whether to refresh the entire preview in case a partial cannot be refreshed.
+	 *                                        A partial render is considered a failure if the render_callback returns
+	 *                                        false.
+	 * }
+	 * @return WP_Customize_Partial             The instance of the panel that was added.
+	 */
+	public function add_partial( $id, $args = array() ) {
+		if ( $id instanceof WP_Customize_Partial ) {
+			$partial = $id;
+		} else {
+			$class = 'WP_Customize_Partial';
+
+			/** This filter is documented in wp-includes/customize/class-wp-customize-selective-refresh.php */
+			$args = apply_filters( 'customize_dynamic_partial_args', $args, $id );
+
+			/** This filter is documented in wp-includes/customize/class-wp-customize-selective-refresh.php */
+			$class = apply_filters( 'customize_dynamic_partial_class', $class, $id, $args );
+
+			$partial = new $class( $this, $id, $args );
+		}
+
+		$this->partials[ $partial->id ] = $partial;
+		return $partial;
+	}
+
+	/**
+	 * Retrieves a partial.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @param string $id Customize Partial ID.
+	 * @return WP_Customize_Partial|null The partial, if set. Otherwise null.
+	 */
+	public function get_partial( $id ) {
+		if ( isset( $this->partials[ $id ] ) ) {
+			return $this->partials[ $id ];
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Removes a partial.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @param string $id Customize Partial ID.
+	 */
+	public function remove_partial( $id ) {
+		unset( $this->partials[ $id ] );
+	}
+
+	/**
+	 * Initializes the Customizer preview.
+	 *
+	 * @since 4.5.0
+	 */
+	public function init_preview() {
+		add_action( 'template_redirect', array( $this, 'handle_render_partials_request' ) );
+		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_preview_scripts' ) );
+	}
+
+	/**
+	 * Enqueues preview scripts.
+	 *
+	 * @since 4.5.0
+	 */
+	public function enqueue_preview_scripts() {
+		wp_enqueue_script( 'customize-selective-refresh' );
+		add_action( 'wp_footer', array( $this, 'export_preview_data' ), 1000 );
+	}
+
+	/**
+	 * Exports data in preview after it has finished rendering so that partials can be added at runtime.
+	 *
+	 * @since 4.5.0
+	 */
+	public function export_preview_data() {
+		$partials = array();
+
+		foreach ( $this->partials() as $partial ) {
+			if ( $partial->check_capabilities() ) {
+				$partials[ $partial->id ] = $partial->json();
+			}
+		}
+
+		$switched_locale = switch_to_locale( get_user_locale() );
+		$l10n = array(
+			'shiftClickToEdit' => __( 'Shift-click to edit this element.' ),
+			'clickEditMenu' => __( 'Click to edit this menu.' ),
+			'clickEditWidget' => __( 'Click to edit this widget.' ),
+			'clickEditTitle' => __( 'Click to edit the site title.' ),
+			'clickEditMisc' => __( 'Click to edit this element.' ),
+			/* translators: %s: document.write() */
+			'badDocumentWrite' => sprintf( __( '%s is forbidden' ), 'document.write()' ),
+		);
+		if ( $switched_locale ) {
+			restore_previous_locale();
+		}
+
+		$exports = array(
+			'partials'       => $partials,
+			'renderQueryVar' => self::RENDER_QUERY_VAR,
+			'l10n'           => $l10n,
+		);
+
+		// Export data to JS.
+		echo sprintf( '<script>var _customizePartialRefreshExports = %s;</script>', wp_json_encode( $exports ) );
+	}
+
+	/**
+	 * Registers dynamically-created partials.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @see WP_Customize_Manager::add_dynamic_settings()
+	 *
+	 * @param array $partial_ids The partial ID to add.
+	 * @return array Added WP_Customize_Partial instances.
+	 */
+	public function add_dynamic_partials( $partial_ids ) {
+		$new_partials = array();
+
+		foreach ( $partial_ids as $partial_id ) {
+
+			// Skip partials already created.
+			$partial = $this->get_partial( $partial_id );
+			if ( $partial ) {
+				continue;
+			}
+
+			$partial_args = false;
+			$partial_class = 'WP_Customize_Partial';
+
+			/**
+			 * Filters a dynamic partial's constructor arguments.
+			 *
+			 * For a dynamic partial to be registered, this filter must be employed
+			 * to override the default false value with an array of args to pass to
+			 * the WP_Customize_Partial constructor.
+			 *
+			 * @since 4.5.0
+			 *
+			 * @param false|array $partial_args The arguments to the WP_Customize_Partial constructor.
+			 * @param string      $partial_id   ID for dynamic partial.
+			 */
+			$partial_args = apply_filters( 'customize_dynamic_partial_args', $partial_args, $partial_id );
+			if ( false === $partial_args ) {
+				continue;
+			}
+
+			/**
+			 * Filters the class used to construct partials.
+			 *
+			 * Allow non-statically created partials to be constructed with custom WP_Customize_Partial subclass.
+			 *
+			 * @since 4.5.0
+			 *
+			 * @param string $partial_class WP_Customize_Partial or a subclass.
+			 * @param string $partial_id    ID for dynamic partial.
+			 * @param array  $partial_args  The arguments to the WP_Customize_Partial constructor.
+			 */
+			$partial_class = apply_filters( 'customize_dynamic_partial_class', $partial_class, $partial_id, $partial_args );
+
+			$partial = new $partial_class( $this, $partial_id, $partial_args );
+
+			$this->add_partial( $partial );
+			$new_partials[] = $partial;
+		}
+		return $new_partials;
+	}
+
+	/**
+	 * Checks whether the request is for rendering partials.
+	 *
+	 * Note that this will not consider whether the request is authorized or valid,
+	 * just that essentially the route is a match.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @return bool Whether the request is for rendering partials.
+	 */
+	public function is_render_partials_request() {
+		return ! empty( $_POST[ self::RENDER_QUERY_VAR ] );
+	}
+
+	/**
+	 * Handles PHP errors triggered during rendering the partials.
+	 *
+	 * These errors will be relayed back to the client in the Ajax response.
+	 *
+	 * @since 4.5.0
+	 *
+	 * @param int    $errno   Error number.
+	 * @param string $errstr  Error string.
+	 * @param string $errfile Error file.
+	 * @param string $errline Error line.
+	 * @return true Always true.
+	 */
+	public function handle_error( $errno, $errstr, $errfile = null, $errline = null ) {
+		$this->triggered_errors[] = array(
+			'partial'      => $this->current_partial_id,
+			'error_number' => $errno,
+			'error_string' => $errstr,
+			'error_file'   => $errfile,
+			'error_line'   => $errline,
+		);
+		return true;
+	}
+
+	/**
+	 * Handles the Ajax request to return the rendered partials for the requested placements.
+	 *
+	 * @since 4.5.0
+	 */
+	public function handle_render_partials_request() {
+		if ( ! $this->is_render_partials_request() ) {
+			return;
+		}
+
+		/*
+		 * Note that is_customize_preview() returning true will entail that the
+		 * user passed the 'customize' capability check and the nonce check, since
+		 * WP_Customize_Manager::setup_theme() is where the previewing flag is set.
+		 */
+		if ( ! is_customize_preview() ) {
+			wp_send_json_error( 'expected_customize_preview', 403 );
+		} elseif ( ! isset( $_POST['partials'] ) ) {
+			wp_send_json_error( 'missing_partials', 400 );
+		}
+
+		// Ensure that doing selective refresh on 404 template doesn't result in fallback rendering behavior (full refreshes).
+		status_header( 200 );
+
+		$partials = json_decode( wp_unslash( $_POST['partials'] ), true );
+
+		if ( ! is_array( $partials ) ) {
+			wp_send_json_error( 'malformed_partials' );
+		}
+
+		$this->add_dynamic_partials( array_keys( $partials ) );
+
+		/**
+		 * Fires immediately before partials are rendered.
+		 *
+		 * Plugins may do things like call wp_enqueue_scripts() and gather a list of the scripts
+		 * and styles which may get enqueued in the response.
+		 *
+		 * @since 4.5.0
+		 *
+		 * @param WP_Customize_Selective_Refresh $this     Selective refresh component.
+		 * @param array                          $partials Placements' context data for the partials rendered in the request.
+		 *                                                 The array is keyed by partial ID, with each item being an array of
+		 *                                                 the placements' context data.
+		 */
+		do_action( 'customize_render_partials_before', $this, $partials );
+
+		set_error_handler( array( $this, 'handle_error' ), error_reporting() );
+
+		$contents = array();
+
+		foreach ( $partials as $partial_id => $container_contexts ) {
+			$this->current_partial_id = $partial_id;
+
+			if ( ! is_array( $container_contexts ) ) {
+				wp_send_json_error( 'malformed_container_contexts' );
+			}
+
+			$partial = $this->get_partial( $partial_id );
+
+			if ( ! $partial || ! $partial->check_capabilities() ) {
+				$contents[ $partial_id ] = null;
+				continue;
+			}
+
+			$contents[ $partial_id ] = array();
+
+			// @todo The array should include not only the contents, but also whether the container is included?
+			if ( empty( $container_contexts ) ) {
+				// Since there are no container contexts, render just once.
+				$contents[ $partial_id ][] = $partial->render( null );
+			} else {
+				foreach ( $container_contexts as $container_context ) {
+					$contents[ $partial_id ][] = $partial->render( $container_context );
+				}
+			}
+		}
+		$this->current_partial_id = null;
+
+		restore_error_handler();
+
+		/**
+		 * Fires immediately after partials are rendered.
+		 *
+		 * Plugins may do things like call wp_footer() to scrape scripts output and return them
+		 * via the {@see 'customize_render_partials_response'} filter.
+		 *
+		 * @since 4.5.0
+		 *
+		 * @param WP_Customize_Selective_Refresh $this     Selective refresh component.
+		 * @param array                          $partials Placements' context data for the partials rendered in the request.
+		 *                                                 The array is keyed by partial ID, with each item being an array of
+		 *                                                 the placements' context data.
+		 */
+		do_action( 'customize_render_partials_after', $this, $partials );
+
+		$response = array(
+			'contents' => $contents,
+		);
+
+		if ( defined( 'WP_DEBUG_DISPLAY' ) && WP_DEBUG_DISPLAY ) {
+			$response['errors'] = $this->triggered_errors;
+		}
+
+		$setting_validities = $this->manager->validate_setting_values( $this->manager->unsanitized_post_values() );
+		$exported_setting_validities = array_map( array( $this->manager, 'prepare_setting_validity_for_js' ), $setting_validities );
+		$response['setting_validities'] = $exported_setting_validities;
+
+		/**
+		 * Filters the response from rendering the partials.
+		 *
+		 * Plugins may use this filter to inject `$scripts` and `$styles`, which are dependencies
+		 * for the partials being rendered. The response data will be available to the client via
+		 * the `render-partials-response` JS event, so the client can then inject the scripts and
+		 * styles into the DOM if they have not already been enqueued there.
+		 *
+		 * If plugins do this, they'll need to take care for any scripts that do `document.write()`
+		 * and make sure that these are not injected, or else to override the function to no-op,
+		 * or else the page will be destroyed.
+		 *
+		 * Plugins should be aware that `$scripts` and `$styles` may eventually be included by
+		 * default in the response.
+		 *
+		 * @since 4.5.0
+		 *
+		 * @param array $response {
+		 *     Response.
+		 *
+		 *     @type array $contents Associative array mapping a partial ID its corresponding array of contents
+		 *                           for the containers requested.
+		 *     @type array $errors   List of errors triggered during rendering of partials, if `WP_DEBUG_DISPLAY`
+		 *                           is enabled.
+		 * }
+		 * @param WP_Customize_Selective_Refresh $this     Selective refresh component.
+		 * @param array                          $partials Placements' context data for the partials rendered in the request.
+		 *                                                 The array is keyed by partial ID, with each item being an array of
+		 *                                                 the placements' context data.
+		 */
+		$response = apply_filters( 'customize_render_partials_response', $response, $this, $partials );
+
+		wp_send_json_success( $response );
+	}
+}