wp-includes/customize/class-wp-customize-selective-refresh.php

   1 <?php
   2 /**
   3  * Customize API: WP_Customize_Selective_Refresh class
   4  *
   5  * @package WordPress
   6  * @subpackage Customize
   7  * @since 4.5.0
   8  */
   9
  10 /**
  11  * Core Customizer class for implementing selective refresh.
  12  *
  13  * @since 4.5.0
  14  */
  15 final class WP_Customize_Selective_Refresh {
  16
  17         /**
  18          * Query var used in requests to render partials.
  19          *
  20          * @since 4.5.0
  21          */
  22         const RENDER_QUERY_VAR = 'wp_customize_render_partials';
  23
  24         /**
  25          * Customize manager.
  26          *
  27          * @since 4.5.0
  28          * @access public
  29          * @var WP_Customize_Manager
  30          */
  31         public $manager;
  32
  33         /**
  34          * Registered instances of WP_Customize_Partial.
  35          *
  36          * @since 4.5.0
  37          * @access protected
  38          * @var WP_Customize_Partial[]
  39          */
  40         protected $partials = array();
  41
  42         /**
  43          * Log of errors triggered when partials are rendered.
  44          *
  45          * @since 4.5.0
  46          * @access private
  47          * @var array
  48          */
  49         protected $triggered_errors = array();
  50
  51         /**
  52          * Keep track of the current partial being rendered.
  53          *
  54          * @since 4.5.0
  55          * @access private
  56          * @var string
  57          */
  58         protected $current_partial_id;
  59
  60         /**
  61          * Plugin bootstrap for Partial Refresh functionality.
  62          *
  63          * @since 4.5.0
  64          * @access public
  65          *
  66          * @param WP_Customize_Manager $manager Manager instance.
  67          */
  68         public function __construct( WP_Customize_Manager $manager ) {
  69                 $this->manager = $manager;
  70                 require_once( ABSPATH . WPINC . '/customize/class-wp-customize-partial.php' );
  71
  72                 add_action( 'customize_preview_init', array( $this, 'init_preview' ) );
  73         }
  74
  75         /**
  76          * Retrieves the registered partials.
  77          *
  78          * @since 4.5.0
  79          * @access public
  80          *
  81          * @return array Partials.
  82          */
  83         public function partials() {
  84                 return $this->partials;
  85         }
  86
  87         /**
  88          * Adds a partial.
  89          *
  90          * @since 4.5.0
  91          * @access public
  92          *
  93          * @param WP_Customize_Partial|string $id   Customize Partial object, or Panel ID.
  94          * @param array                       $args Optional. Partial arguments. Default empty array.
  95          * @return WP_Customize_Partial             The instance of the panel that was added.
  96          */
  97         public function add_partial( $id, $args = array() ) {
  98                 if ( $id instanceof WP_Customize_Partial ) {
  99                         $partial = $id;
 100                 } else {
 101                         $class = 'WP_Customize_Partial';
 102
 103                         /** This filter (will be) documented in wp-includes/class-wp-customize-manager.php */
 104                         $args = apply_filters( 'customize_dynamic_partial_args', $args, $id );
 105
 106                         /** This filter (will be) documented in wp-includes/class-wp-customize-manager.php */
 107                         $class = apply_filters( 'customize_dynamic_partial_class', $class, $id, $args );
 108
 109                         $partial = new $class( $this, $id, $args );
 110                 }
 111
 112                 $this->partials[ $partial->id ] = $partial;
 113                 return $partial;
 114         }
 115
 116         /**
 117          * Retrieves a partial.
 118          *
 119          * @since 4.5.0
 120          * @access public
 121          *
 122          * @param string $id Customize Partial ID.
 123          * @return WP_Customize_Partial|null The partial, if set. Otherwise null.
 124          */
 125         public function get_partial( $id ) {
 126                 if ( isset( $this->partials[ $id ] ) ) {
 127                         return $this->partials[ $id ];
 128                 } else {
 129                         return null;
 130                 }
 131         }
 132
 133         /**
 134          * Removes a partial.
 135          *
 136          * @since 4.5.0
 137          * @access public
 138          *
 139          * @param string $id Customize Partial ID.
 140          */
 141         public function remove_partial( $id ) {
 142                 unset( $this->partials[ $id ] );
 143         }
 144
 145         /**
 146          * Initializes the Customizer preview.
 147          *
 148          * @since 4.5.0
 149          * @access public
 150          */
 151         public function init_preview() {
 152                 add_action( 'template_redirect', array( $this, 'handle_render_partials_request' ) );
 153                 add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_preview_scripts' ) );
 154         }
 155
 156         /**
 157          * Enqueues preview scripts.
 158          *
 159          * @since 4.5.0
 160          * @access public
 161          */
 162         public function enqueue_preview_scripts() {
 163                 wp_enqueue_script( 'customize-selective-refresh' );
 164                 add_action( 'wp_footer', array( $this, 'export_preview_data' ), 1000 );
 165         }
 166
 167         /**
 168          * Exports data in preview after it has finished rendering so that partials can be added at runtime.
 169          *
 170          * @since 4.5.0
 171          * @access public
 172          */
 173         public function export_preview_data() {
 174                 $partials = array();
 175
 176                 foreach ( $this->partials() as $partial ) {
 177                         if ( $partial->check_capabilities() ) {
 178                                 $partials[ $partial->id ] = $partial->json();
 179                         }
 180                 }
 181
 182                 $exports = array(
 183                         'partials'       => $partials,
 184                         'renderQueryVar' => self::RENDER_QUERY_VAR,
 185                         'l10n'           => array(
 186                                 'shiftClickToEdit' => __( 'Shift-click to edit this element.' ),
 187                                 /* translators: %s: document.write() */
 188                                 'badDocumentWrite' => sprintf( __( '%s is forbidden' ), 'document.write()' ),
 189                         ),
 190                 );
 191
 192                 // Export data to JS.
 193                 echo sprintf( '<script>var _customizePartialRefreshExports = %s;</script>', wp_json_encode( $exports ) );
 194         }
 195
 196         /**
 197          * Registers dynamically-created partials.
 198          *
 199          * @since 4.5.0
 200          * @access public
 201          *
 202          * @see WP_Customize_Manager::add_dynamic_settings()
 203          *
 204          * @param array $partial_ids The partial ID to add.
 205          * @return array Added WP_Customize_Partial instances.
 206          */
 207         public function add_dynamic_partials( $partial_ids ) {
 208                 $new_partials = array();
 209
 210                 foreach ( $partial_ids as $partial_id ) {
 211
 212                         // Skip partials already created.
 213                         $partial = $this->get_partial( $partial_id );
 214                         if ( $partial ) {
 215                                 continue;
 216                         }
 217
 218                         $partial_args = false;
 219                         $partial_class = 'WP_Customize_Partial';
 220
 221                         /**
 222                          * Filters a dynamic partial's constructor arguments.
 223                          *
 224                          * For a dynamic partial to be registered, this filter must be employed
 225                          * to override the default false value with an array of args to pass to
 226                          * the WP_Customize_Partial constructor.
 227                          *
 228                          * @since 4.5.0
 229                          *
 230                          * @param false|array $partial_args The arguments to the WP_Customize_Partial constructor.
 231                          * @param string      $partial_id   ID for dynamic partial.
 232                          */
 233                         $partial_args = apply_filters( 'customize_dynamic_partial_args', $partial_args, $partial_id );
 234                         if ( false === $partial_args ) {
 235                                 continue;
 236                         }
 237
 238                         /**
 239                          * Filters the class used to construct partials.
 240                          *
 241                          * Allow non-statically created partials to be constructed with custom WP_Customize_Partial subclass.
 242                          *
 243                          * @since 4.5.0
 244                          *
 245                          * @param string $partial_class WP_Customize_Partial or a subclass.
 246                          * @param string $partial_id    ID for dynamic partial.
 247                          * @param array  $partial_args  The arguments to the WP_Customize_Partial constructor.
 248                          */
 249                         $partial_class = apply_filters( 'customize_dynamic_partial_class', $partial_class, $partial_id, $partial_args );
 250
 251                         $partial = new $partial_class( $this, $partial_id, $partial_args );
 252
 253                         $this->add_partial( $partial );
 254                         $new_partials[] = $partial;
 255                 }
 256                 return $new_partials;
 257         }
 258
 259         /**
 260          * Checks whether the request is for rendering partials.
 261          *
 262          * Note that this will not consider whether the request is authorized or valid,
 263          * just that essentially the route is a match.
 264          *
 265          * @since 4.5.0
 266          * @access public
 267          *
 268          * @return bool Whether the request is for rendering partials.
 269          */
 270         public function is_render_partials_request() {
 271                 return ! empty( $_POST[ self::RENDER_QUERY_VAR ] );
 272         }
 273
 274         /**
 275          * Handles PHP errors triggered during rendering the partials.
 276          *
 277          * These errors will be relayed back to the client in the Ajax response.
 278          *
 279          * @since 4.5.0
 280          * @access private
 281          *
 282          * @param int    $errno   Error number.
 283          * @param string $errstr  Error string.
 284          * @param string $errfile Error file.
 285          * @param string $errline Error line.
 286          * @return true Always true.
 287          */
 288         public function handle_error( $errno, $errstr, $errfile = null, $errline = null ) {
 289                 $this->triggered_errors[] = array(
 290                         'partial'      => $this->current_partial_id,
 291                         'error_number' => $errno,
 292                         'error_string' => $errstr,
 293                         'error_file'   => $errfile,
 294                         'error_line'   => $errline,
 295                 );
 296                 return true;
 297         }
 298
 299         /**
 300          * Handles the Ajax request to return the rendered partials for the requested placements.
 301          *
 302          * @since 4.5.0
 303          * @access public
 304          */
 305         public function handle_render_partials_request() {
 306                 if ( ! $this->is_render_partials_request() ) {
 307                         return;
 308                 }
 309
 310                 $this->manager->remove_preview_signature();
 311
 312                 /*
 313                  * Note that is_customize_preview() returning true will entail that the
 314                  * user passed the 'customize' capability check and the nonce check, since
 315                  * WP_Customize_Manager::setup_theme() is where the previewing flag is set.
 316                  */
 317                 if ( ! is_customize_preview() ) {
 318                         status_header( 403 );
 319                         wp_send_json_error( 'expected_customize_preview' );
 320                 } else if ( ! isset( $_POST['partials'] ) ) {
 321                         status_header( 400 );
 322                         wp_send_json_error( 'missing_partials' );
 323                 }
 324
 325                 $partials = json_decode( wp_unslash( $_POST['partials'] ), true );
 326
 327                 if ( ! is_array( $partials ) ) {
 328                         wp_send_json_error( 'malformed_partials' );
 329                 }
 330
 331                 $this->add_dynamic_partials( array_keys( $partials ) );
 332
 333                 /**
 334                  * Fires immediately before partials are rendered.
 335                  *
 336                  * Plugins may do things like call wp_enqueue_scripts() and gather a list of the scripts
 337                  * and styles which may get enqueued in the response.
 338                  *
 339                  * @since 4.5.0
 340                  *
 341                  * @param WP_Customize_Selective_Refresh $this     Selective refresh component.
 342                  * @param array                          $partials Placements' context data for the partials rendered in the request.
 343                  *                                                 The array is keyed by partial ID, with each item being an array of
 344                  *                                                 the placements' context data.
 345                  */
 346                 do_action( 'customize_render_partials_before', $this, $partials );
 347
 348                 set_error_handler( array( $this, 'handle_error' ), error_reporting() );
 349
 350                 $contents = array();
 351
 352                 foreach ( $partials as $partial_id => $container_contexts ) {
 353                         $this->current_partial_id = $partial_id;
 354
 355                         if ( ! is_array( $container_contexts ) ) {
 356                                 wp_send_json_error( 'malformed_container_contexts' );
 357                         }
 358
 359                         $partial = $this->get_partial( $partial_id );
 360
 361                         if ( ! $partial || ! $partial->check_capabilities() ) {
 362                                 $contents[ $partial_id ] = null;
 363                                 continue;
 364                         }
 365
 366                         $contents[ $partial_id ] = array();
 367
 368                         // @todo The array should include not only the contents, but also whether the container is included?
 369                         if ( empty( $container_contexts ) ) {
 370                                 // Since there are no container contexts, render just once.
 371                                 $contents[ $partial_id ][] = $partial->render( null );
 372                         } else {
 373                                 foreach ( $container_contexts as $container_context ) {
 374                                         $contents[ $partial_id ][] = $partial->render( $container_context );
 375                                 }
 376                         }
 377                 }
 378                 $this->current_partial_id = null;
 379
 380                 restore_error_handler();
 381
 382                 /**
 383                  * Fires immediately after partials are rendered.
 384                  *
 385                  * Plugins may do things like call wp_footer() to scrape scripts output and return them
 386                  * via the {@see 'customize_render_partials_response'} filter.
 387                  *
 388                  * @since 4.5.0
 389                  *
 390                  * @param WP_Customize_Selective_Refresh $this     Selective refresh component.
 391                  * @param array                          $partials Placements' context data for the partials rendered in the request.
 392                  *                                                 The array is keyed by partial ID, with each item being an array of
 393                  *                                                 the placements' context data.
 394                  */
 395                 do_action( 'customize_render_partials_after', $this, $partials );
 396
 397                 $response = array(
 398                         'contents' => $contents,
 399                 );
 400
 401                 if ( defined( 'WP_DEBUG_DISPLAY' ) && WP_DEBUG_DISPLAY ) {
 402                         $response['errors'] = $this->triggered_errors;
 403                 }
 404
 405                 $setting_validities = $this->manager->validate_setting_values( $this->manager->unsanitized_post_values() );
 406                 $exported_setting_validities = array_map( array( $this->manager, 'prepare_setting_validity_for_js' ), $setting_validities );
 407                 $response['setting_validities'] = $exported_setting_validities;
 408
 409                 /**
 410                  * Filters the response from rendering the partials.
 411                  *
 412                  * Plugins may use this filter to inject `$scripts` and `$styles`, which are dependencies
 413                  * for the partials being rendered. The response data will be available to the client via
 414                  * the `render-partials-response` JS event, so the client can then inject the scripts and
 415                  * styles into the DOM if they have not already been enqueued there.
 416                  *
 417                  * If plugins do this, they'll need to take care for any scripts that do `document.write()`
 418                  * and make sure that these are not injected, or else to override the function to no-op,
 419                  * or else the page will be destroyed.
 420                  *
 421                  * Plugins should be aware that `$scripts` and `$styles` may eventually be included by
 422                  * default in the response.
 423                  *
 424                  * @since 4.5.0
 425                  *
 426                  * @param array $response {
 427                  *     Response.
 428                  *
 429                  *     @type array $contents Associative array mapping a partial ID its corresponding array of contents
 430                  *                           for the containers requested.
 431                  *     @type array $errors   List of errors triggered during rendering of partials, if `WP_DEBUG_DISPLAY`
 432                  *                           is enabled.
 433                  * }
 434                  * @param WP_Customize_Selective_Refresh $this     Selective refresh component.
 435                  * @param array                          $partials Placements' context data for the partials rendered in the request.
 436                  *                                                 The array is keyed by partial ID, with each item being an array of
 437                  *                                                 the placements' context data.
 438                  */
 439                 $response = apply_filters( 'customize_render_partials_response', $response, $this, $partials );
 440
 441                 wp_send_json_success( $response );
 442         }
 443 }