class-wp-rest-widgets-controller.php 25.7 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874
<?php
/**
 * REST API: WP_REST_Widgets_Controller class
 *
 * @package WordPress
 * @subpackage REST_API
 * @since 5.8.0
 */

/**
 * Core class to access widgets via the REST API.
 *
 * @since 5.8.0
 *
 * @see WP_REST_Controller
 */
class WP_REST_Widgets_Controller extends WP_REST_Controller {

	/**
	 * Tracks whether {@see retrieve_widgets()} has been called in the current request.
	 *
	 * @since 5.9.0
	 * @var bool
	 */
	protected $widgets_retrieved = false;

	/**
	 * Whether the controller supports batching.
	 *
	 * @since 5.9.0
	 * @var array
	 */
	protected $allow_batch = array( 'v1' => true );

	/**
	 * Widgets controller constructor.
	 *
	 * @since 5.8.0
	 */
	public function __construct() {
		$this->namespace = 'wp/v2';
		$this->rest_base = 'widgets';
	}

	/**
	 * Registers the widget routes for the controller.
	 *
	 * @since 5.8.0
	 */
	public function register_routes() {
		register_rest_route(
			$this->namespace,
			$this->rest_base,
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_items' ),
					'permission_callback' => array( $this, 'get_items_permissions_check' ),
					'args'                => $this->get_collection_params(),
				),
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'create_item' ),
					'permission_callback' => array( $this, 'create_item_permissions_check' ),
					'args'                => $this->get_endpoint_args_for_item_schema(),
				),
				'allow_batch' => $this->allow_batch,
				'schema'      => array( $this, 'get_public_item_schema' ),
			)
		);

		register_rest_route(
			$this->namespace,
			$this->rest_base . '/(?P<id>[\w\-]+)',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_item' ),
					'permission_callback' => array( $this, 'get_item_permissions_check' ),
					'args'                => array(
						'context' => $this->get_context_param( array( 'default' => 'view' ) ),
					),
				),
				array(
					'methods'             => WP_REST_Server::EDITABLE,
					'callback'            => array( $this, 'update_item' ),
					'permission_callback' => array( $this, 'update_item_permissions_check' ),
					'args'                => $this->get_endpoint_args_for_item_schema( WP_REST_Server::EDITABLE ),
				),
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'delete_item' ),
					'permission_callback' => array( $this, 'delete_item_permissions_check' ),
					'args'                => array(
						'force' => array(
							'description' => __( 'Whether to force removal of the widget, or move it to the inactive sidebar.' ),
							'type'        => 'boolean',
						),
					),
				),
				'allow_batch' => $this->allow_batch,
				'schema'      => array( $this, 'get_public_item_schema' ),
			)
		);
	}

	/**
	 * Checks if a given request has access to get widgets.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
	 */
	public function get_items_permissions_check( $request ) {
		$this->retrieve_widgets();
		if ( isset( $request['sidebar'] ) && $this->check_read_sidebar_permission( $request['sidebar'] ) ) {
			return true;
		}

		foreach ( wp_get_sidebars_widgets() as $sidebar_id => $widget_ids ) {
			if ( $this->check_read_sidebar_permission( $sidebar_id ) ) {
				return true;
			}
		}

		return $this->permissions_check( $request );
	}

	/**
	 * Retrieves a collection of widgets.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function get_items( $request ) {
		$this->retrieve_widgets();

		$prepared          = array();
		$permissions_check = $this->permissions_check( $request );

		foreach ( wp_get_sidebars_widgets() as $sidebar_id => $widget_ids ) {
			if ( isset( $request['sidebar'] ) && $sidebar_id !== $request['sidebar'] ) {
				continue;
			}

			if ( is_wp_error( $permissions_check ) && ! $this->check_read_sidebar_permission( $sidebar_id ) ) {
				continue;
			}

			foreach ( $widget_ids as $widget_id ) {
				$response = $this->prepare_item_for_response( compact( 'sidebar_id', 'widget_id' ), $request );

				if ( ! is_wp_error( $response ) ) {
					$prepared[] = $this->prepare_response_for_collection( $response );
				}
			}
		}

		return new WP_REST_Response( $prepared );
	}

	/**
	 * Checks if a given request has access to get a widget.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
	 */
	public function get_item_permissions_check( $request ) {
		$this->retrieve_widgets();

		$widget_id  = $request['id'];
		$sidebar_id = wp_find_widgets_sidebar( $widget_id );

		if ( $sidebar_id && $this->check_read_sidebar_permission( $sidebar_id ) ) {
			return true;
		}

		return $this->permissions_check( $request );
	}

	/**
	 * Checks if a sidebar can be read publicly.
	 *
	 * @since 5.9.0
	 *
	 * @param string $sidebar_id The sidebar ID.
	 * @return bool Whether the sidebar can be read.
	 */
	protected function check_read_sidebar_permission( $sidebar_id ) {
		$sidebar = wp_get_sidebar( $sidebar_id );

		return ! empty( $sidebar['show_in_rest'] );
	}

	/**
	 * Gets an individual widget.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function get_item( $request ) {
		$this->retrieve_widgets();

		$widget_id  = $request['id'];
		$sidebar_id = wp_find_widgets_sidebar( $widget_id );

		if ( is_null( $sidebar_id ) ) {
			return new WP_Error(
				'rest_widget_not_found',
				__( 'No widget was found with that id.' ),
				array( 'status' => 404 )
			);
		}

		return $this->prepare_item_for_response( compact( 'widget_id', 'sidebar_id' ), $request );
	}

	/**
	 * Checks if a given request has access to create widgets.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
	 */
	public function create_item_permissions_check( $request ) {
		return $this->permissions_check( $request );
	}

	/**
	 * Creates a widget.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function create_item( $request ) {
		$sidebar_id = $request['sidebar'];

		$widget_id = $this->save_widget( $request, $sidebar_id );

		if ( is_wp_error( $widget_id ) ) {
			return $widget_id;
		}

		wp_assign_widget_to_sidebar( $widget_id, $sidebar_id );

		$request['context'] = 'edit';

		$response = $this->prepare_item_for_response( compact( 'sidebar_id', 'widget_id' ), $request );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response->set_status( 201 );

		return $response;
	}

	/**
	 * Checks if a given request has access to update widgets.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
	 */
	public function update_item_permissions_check( $request ) {
		return $this->permissions_check( $request );
	}

	/**
	 * Updates an existing widget.
	 *
	 * @since 5.8.0
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function update_item( $request ) {
		global $wp_widget_factory;

		/*
		 * retrieve_widgets() contains logic to move "hidden" or "lost" widgets to the
		 * wp_inactive_widgets sidebar based on the contents of the $sidebars_widgets global.
		 *
		 * When batch requests are processed, this global is not properly updated by previous
		 * calls, resulting in widgets incorrectly being moved to the wp_inactive_widgets
		 * sidebar.
		 *
		 * See https://core.trac.wordpress.org/ticket/53657.
		 */
		wp_get_sidebars_widgets();
		$this->retrieve_widgets();

		$widget_id  = $request['id'];
		$sidebar_id = wp_find_widgets_sidebar( $widget_id );

		// Allow sidebar to be unset or missing when widget is not a WP_Widget.
		$parsed_id     = wp_parse_widget_id( $widget_id );
		$widget_object = $wp_widget_factory->get_widget_object( $parsed_id['id_base'] );
		if ( is_null( $sidebar_id ) && $widget_object ) {
			return new WP_Error(
				'rest_widget_not_found',
				__( 'No widget was found with that id.' ),
				array( 'status' => 404 )
			);
		}

		if (
			$request->has_param( 'instance' ) ||
			$request->has_param( 'form_data' )
		) {
			$maybe_error = $this->save_widget( $request, $sidebar_id );
			if ( is_wp_error( $maybe_error ) ) {
				return $maybe_error;
			}
		}

		if ( $request->has_param( 'sidebar' ) ) {
			if ( $sidebar_id !== $request['sidebar'] ) {
				$sidebar_id = $request['sidebar'];
				wp_assign_widget_to_sidebar( $widget_id, $sidebar_id );
			}
		}

		$request['context'] = 'edit';

		return $this->prepare_item_for_response( compact( 'widget_id', 'sidebar_id' ), $request );
	}

	/**
	 * Checks if a given request has access to delete widgets.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
	 */
	public function delete_item_permissions_check( $request ) {
		return $this->permissions_check( $request );
	}

	/**
	 * Deletes a widget.
	 *
	 * @since 5.8.0
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 * @global array             $wp_registered_widget_updates The registered widget update functions.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function delete_item( $request ) {
		global $wp_widget_factory, $wp_registered_widget_updates;

		/*
		 * retrieve_widgets() contains logic to move "hidden" or "lost" widgets to the
		 * wp_inactive_widgets sidebar based on the contents of the $sidebars_widgets global.
		 *
		 * When batch requests are processed, this global is not properly updated by previous
		 * calls, resulting in widgets incorrectly being moved to the wp_inactive_widgets
		 * sidebar.
		 *
		 * See https://core.trac.wordpress.org/ticket/53657.
		 */
		wp_get_sidebars_widgets();
		$this->retrieve_widgets();

		$widget_id  = $request['id'];
		$sidebar_id = wp_find_widgets_sidebar( $widget_id );

		if ( is_null( $sidebar_id ) ) {
			return new WP_Error(
				'rest_widget_not_found',
				__( 'No widget was found with that id.' ),
				array( 'status' => 404 )
			);
		}

		$request['context'] = 'edit';

		if ( $request['force'] ) {
			$response = $this->prepare_item_for_response( compact( 'widget_id', 'sidebar_id' ), $request );

			$parsed_id = wp_parse_widget_id( $widget_id );
			$id_base   = $parsed_id['id_base'];

			$original_post    = $_POST;
			$original_request = $_REQUEST;

			$_POST    = array(
				'sidebar'         => $sidebar_id,
				"widget-$id_base" => array(),
				'the-widget-id'   => $widget_id,
				'delete_widget'   => '1',
			);
			$_REQUEST = $_POST;

			/** This action is documented in wp-admin/widgets-form.php */
			do_action( 'delete_widget', $widget_id, $sidebar_id, $id_base );

			$callback = $wp_registered_widget_updates[ $id_base ]['callback'];
			$params   = $wp_registered_widget_updates[ $id_base ]['params'];

			if ( is_callable( $callback ) ) {
				ob_start();
				call_user_func_array( $callback, $params );
				ob_end_clean();
			}

			$_POST    = $original_post;
			$_REQUEST = $original_request;

			$widget_object = $wp_widget_factory->get_widget_object( $id_base );

			if ( $widget_object ) {
				/*
				 * WP_Widget sets `updated = true` after an update to prevent more than one widget
				 * from being saved per request. This isn't what we want in the REST API, though,
				 * as we support batch requests.
				 */
				$widget_object->updated = false;
			}

			wp_assign_widget_to_sidebar( $widget_id, '' );

			$response->set_data(
				array(
					'deleted'  => true,
					'previous' => $response->get_data(),
				)
			);
		} else {
			wp_assign_widget_to_sidebar( $widget_id, 'wp_inactive_widgets' );

			$response = $this->prepare_item_for_response(
				array(
					'sidebar_id' => 'wp_inactive_widgets',
					'widget_id'  => $widget_id,
				),
				$request
			);
		}

		/**
		 * Fires after a widget is deleted via the REST API.
		 *
		 * @since 5.8.0
		 *
		 * @param string                    $widget_id  ID of the widget marked for deletion.
		 * @param string                    $sidebar_id ID of the sidebar the widget was deleted from.
		 * @param WP_REST_Response|WP_Error $response   The response data, or WP_Error object on failure.
		 * @param WP_REST_Request           $request    The request sent to the API.
		 */
		do_action( 'rest_delete_widget', $widget_id, $sidebar_id, $response, $request );

		return $response;
	}

	/**
	 * Performs a permissions check for managing widgets.
	 *
	 * @since 5.8.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error
	 */
	protected function permissions_check( $request ) {
		if ( ! current_user_can( 'edit_theme_options' ) ) {
			return new WP_Error(
				'rest_cannot_manage_widgets',
				__( 'Sorry, you are not allowed to manage widgets on this site.' ),
				array(
					'status' => rest_authorization_required_code(),
				)
			);
		}

		return true;
	}

	/**
	 * Looks for "lost" widgets once per request.
	 *
	 * @since 5.9.0
	 *
	 * @see retrieve_widgets()
	 */
	protected function retrieve_widgets() {
		if ( ! $this->widgets_retrieved ) {
			retrieve_widgets();
			$this->widgets_retrieved = true;
		}
	}

	/**
	 * Saves the widget in the request object.
	 *
	 * @since 5.8.0
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 * @global array             $wp_registered_widget_updates The registered widget update functions.
	 *
	 * @param WP_REST_Request $request    Full details about the request.
	 * @param string          $sidebar_id ID of the sidebar the widget belongs to.
	 * @return string|WP_Error The saved widget ID.
	 */
	protected function save_widget( $request, $sidebar_id ) {
		global $wp_widget_factory, $wp_registered_widget_updates;

		require_once ABSPATH . 'wp-admin/includes/widgets.php'; // For next_widget_id_number().

		if ( isset( $request['id'] ) ) {
			// Saving an existing widget.
			$id            = $request['id'];
			$parsed_id     = wp_parse_widget_id( $id );
			$id_base       = $parsed_id['id_base'];
			$number        = isset( $parsed_id['number'] ) ? $parsed_id['number'] : null;
			$widget_object = $wp_widget_factory->get_widget_object( $id_base );
			$creating      = false;
		} elseif ( $request['id_base'] ) {
			// Saving a new widget.
			$id_base       = $request['id_base'];
			$widget_object = $wp_widget_factory->get_widget_object( $id_base );
			$number        = $widget_object ? next_widget_id_number( $id_base ) : null;
			$id            = $widget_object ? $id_base . '-' . $number : $id_base;
			$creating      = true;
		} else {
			return new WP_Error(
				'rest_invalid_widget',
				__( 'Widget type (id_base) is required.' ),
				array( 'status' => 400 )
			);
		}

		if ( ! isset( $wp_registered_widget_updates[ $id_base ] ) ) {
			return new WP_Error(
				'rest_invalid_widget',
				__( 'The provided widget type (id_base) cannot be updated.' ),
				array( 'status' => 400 )
			);
		}

		if ( isset( $request['instance'] ) ) {
			if ( ! $widget_object ) {
				return new WP_Error(
					'rest_invalid_widget',
					__( 'Cannot set instance on a widget that does not extend WP_Widget.' ),
					array( 'status' => 400 )
				);
			}

			if ( isset( $request['instance']['raw'] ) ) {
				if ( empty( $widget_object->widget_options['show_instance_in_rest'] ) ) {
					return new WP_Error(
						'rest_invalid_widget',
						__( 'Widget type does not support raw instances.' ),
						array( 'status' => 400 )
					);
				}
				$instance = $request['instance']['raw'];
			} elseif ( isset( $request['instance']['encoded'], $request['instance']['hash'] ) ) {
				$serialized_instance = base64_decode( $request['instance']['encoded'] );
				if ( ! hash_equals( wp_hash( $serialized_instance ), $request['instance']['hash'] ) ) {
					return new WP_Error(
						'rest_invalid_widget',
						__( 'The provided instance is malformed.' ),
						array( 'status' => 400 )
					);
				}
				$instance = unserialize( $serialized_instance );
			} else {
				return new WP_Error(
					'rest_invalid_widget',
					__( 'The provided instance is invalid. Must contain raw OR encoded and hash.' ),
					array( 'status' => 400 )
				);
			}

			$form_data = array(
				"widget-$id_base" => array(
					$number => $instance,
				),
				'sidebar'         => $sidebar_id,
			);
		} elseif ( isset( $request['form_data'] ) ) {
			$form_data = $request['form_data'];
		} else {
			$form_data = array();
		}

		$original_post    = $_POST;
		$original_request = $_REQUEST;

		foreach ( $form_data as $key => $value ) {
			$slashed_value    = wp_slash( $value );
			$_POST[ $key ]    = $slashed_value;
			$_REQUEST[ $key ] = $slashed_value;
		}

		$callback = $wp_registered_widget_updates[ $id_base ]['callback'];
		$params   = $wp_registered_widget_updates[ $id_base ]['params'];

		if ( is_callable( $callback ) ) {
			ob_start();
			call_user_func_array( $callback, $params );
			ob_end_clean();
		}

		$_POST    = $original_post;
		$_REQUEST = $original_request;

		if ( $widget_object ) {
			// Register any multi-widget that the update callback just created.
			$widget_object->_set( $number );
			$widget_object->_register_one( $number );

			/*
			 * WP_Widget sets `updated = true` after an update to prevent more than one widget
			 * from being saved per request. This isn't what we want in the REST API, though,
			 * as we support batch requests.
			 */
			$widget_object->updated = false;
		}

		/**
		 * Fires after a widget is created or updated via the REST API.
		 *
		 * @since 5.8.0
		 *
		 * @param string          $id         ID of the widget being saved.
		 * @param string          $sidebar_id ID of the sidebar containing the widget being saved.
		 * @param WP_REST_Request $request    Request object.
		 * @param bool            $creating   True when creating a widget, false when updating.
		 */
		do_action( 'rest_after_save_widget', $id, $sidebar_id, $request, $creating );

		return $id;
	}

	/**
	 * Prepares the widget for the REST response.
	 *
	 * @since 5.8.0
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 * @global array             $wp_registered_widgets The registered widgets.
	 *
	 * @param array           $item    An array containing a widget_id and sidebar_id.
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function prepare_item_for_response( $item, $request ) {
		global $wp_widget_factory, $wp_registered_widgets;

		$widget_id  = $item['widget_id'];
		$sidebar_id = $item['sidebar_id'];

		if ( ! isset( $wp_registered_widgets[ $widget_id ] ) ) {
			return new WP_Error(
				'rest_invalid_widget',
				__( 'The requested widget is invalid.' ),
				array( 'status' => 500 )
			);
		}

		$widget    = $wp_registered_widgets[ $widget_id ];
		$parsed_id = wp_parse_widget_id( $widget_id );
		$fields    = $this->get_fields_for_response( $request );

		$prepared = array(
			'id'            => $widget_id,
			'id_base'       => $parsed_id['id_base'],
			'sidebar'       => $sidebar_id,
			'rendered'      => '',
			'rendered_form' => null,
			'instance'      => null,
		);

		if (
			rest_is_field_included( 'rendered', $fields ) &&
			'wp_inactive_widgets' !== $sidebar_id
		) {
			$prepared['rendered'] = trim( wp_render_widget( $widget_id, $sidebar_id ) );
		}

		if ( rest_is_field_included( 'rendered_form', $fields ) ) {
			$rendered_form = wp_render_widget_control( $widget_id );
			if ( ! is_null( $rendered_form ) ) {
				$prepared['rendered_form'] = trim( $rendered_form );
			}
		}

		if ( rest_is_field_included( 'instance', $fields ) ) {
			$widget_object = $wp_widget_factory->get_widget_object( $parsed_id['id_base'] );
			if ( $widget_object && isset( $parsed_id['number'] ) ) {
				$all_instances                   = $widget_object->get_settings();
				$instance                        = $all_instances[ $parsed_id['number'] ];
				$serialized_instance             = serialize( $instance );
				$prepared['instance']['encoded'] = base64_encode( $serialized_instance );
				$prepared['instance']['hash']    = wp_hash( $serialized_instance );

				if ( ! empty( $widget_object->widget_options['show_instance_in_rest'] ) ) {
					// Use new stdClass so that JSON result is {} and not [].
					$prepared['instance']['raw'] = empty( $instance ) ? new stdClass : $instance;
				}
			}
		}

		$context  = ! empty( $request['context'] ) ? $request['context'] : 'view';
		$prepared = $this->add_additional_fields_to_object( $prepared, $request );
		$prepared = $this->filter_response_by_context( $prepared, $context );

		$response = rest_ensure_response( $prepared );

		$response->add_links( $this->prepare_links( $prepared ) );

		/**
		 * Filters the REST API response for a widget.
		 *
		 * @since 5.8.0
		 *
		 * @param WP_REST_Response|WP_Error $response The response object, or WP_Error object on failure.
		 * @param array                     $widget   The registered widget data.
		 * @param WP_REST_Request           $request  Request used to generate the response.
		 */
		return apply_filters( 'rest_prepare_widget', $response, $widget, $request );
	}

	/**
	 * Prepares links for the widget.
	 *
	 * @since 5.8.0
	 *
	 * @param array $prepared Widget.
	 * @return array Links for the given widget.
	 */
	protected function prepare_links( $prepared ) {
		$id_base = ! empty( $prepared['id_base'] ) ? $prepared['id_base'] : $prepared['id'];

		return array(
			'self'                      => array(
				'href' => rest_url( sprintf( '%s/%s/%s', $this->namespace, $this->rest_base, $prepared['id'] ) ),
			),
			'collection'                => array(
				'href' => rest_url( sprintf( '%s/%s', $this->namespace, $this->rest_base ) ),
			),
			'about'                     => array(
				'href'       => rest_url( sprintf( 'wp/v2/widget-types/%s', $id_base ) ),
				'embeddable' => true,
			),
			'https://api.w.org/sidebar' => array(
				'href' => rest_url( sprintf( 'wp/v2/sidebars/%s/', $prepared['sidebar'] ) ),
			),
		);
	}

	/**
	 * Gets the list of collection params.
	 *
	 * @since 5.8.0
	 *
	 * @return array[]
	 */
	public function get_collection_params() {
		return array(
			'context' => $this->get_context_param( array( 'default' => 'view' ) ),
			'sidebar' => array(
				'description' => __( 'The sidebar to return widgets for.' ),
				'type'        => 'string',
			),
		);
	}

	/**
	 * Retrieves the widget's schema, conforming to JSON Schema.
	 *
	 * @since 5.8.0
	 *
	 * @return array Item schema data.
	 */
	public function get_item_schema() {
		if ( $this->schema ) {
			return $this->add_additional_fields_schema( $this->schema );
		}

		$this->schema = array(
			'$schema'    => 'http://json-schema.org/draft-04/schema#',
			'title'      => 'widget',
			'type'       => 'object',
			'properties' => array(
				'id'            => array(
					'description' => __( 'Unique identifier for the widget.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'id_base'       => array(
					'description' => __( 'The type of the widget. Corresponds to ID in widget-types endpoint.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'sidebar'       => array(
					'description' => __( 'The sidebar the widget belongs to.' ),
					'type'        => 'string',
					'default'     => 'wp_inactive_widgets',
					'required'    => true,
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'rendered'      => array(
					'description' => __( 'HTML representation of the widget.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit', 'embed' ),
					'readonly'    => true,
				),
				'rendered_form' => array(
					'description' => __( 'HTML representation of the widget admin form.' ),
					'type'        => 'string',
					'context'     => array( 'edit' ),
					'readonly'    => true,
				),
				'instance'      => array(
					'description' => __( 'Instance settings of the widget, if supported.' ),
					'type'        => 'object',
					'context'     => array( 'edit' ),
					'default'     => null,
					'properties'  => array(
						'encoded' => array(
							'description' => __( 'Base64 encoded representation of the instance settings.' ),
							'type'        => 'string',
							'context'     => array( 'edit' ),
						),
						'hash'    => array(
							'description' => __( 'Cryptographic hash of the instance settings.' ),
							'type'        => 'string',
							'context'     => array( 'edit' ),
						),
						'raw'     => array(
							'description' => __( 'Unencoded instance settings, if supported.' ),
							'type'        => 'object',
							'context'     => array( 'edit' ),
						),
					),
				),
				'form_data'     => array(
					'description' => __( 'URL-encoded form data from the widget admin form. Used to update a widget that does not support instance. Write only.' ),
					'type'        => 'string',
					'context'     => array(),
					'arg_options' => array(
						'sanitize_callback' => static function( $string ) {
							$array = array();
							wp_parse_str( $string, $array );
							return $array;
						},
					),
				),
			),
		);

		return $this->add_additional_fields_schema( $this->schema );
	}
}