wp-includes/class-wp-customize-widgets.php

   1 <?php
   2 /**
   3  * WordPress Customize Widgets classes
   4  *
   5  * @package WordPress
   6  * @subpackage Customize
   7  * @since 3.9.0
   8  */
   9
  10 /**
  11  * Customize Widgets class.
  12  *
  13  * Implements widget management in the Customizer.
  14  *
  15  * @since 3.9.0
  16  *
  17  * @see WP_Customize_Manager
  18  */
  19 final class WP_Customize_Widgets {
  20
  21         /**
  22          * WP_Customize_Manager instance.
  23          *
  24          * @since 3.9.0
  25          * @access public
  26          * @var WP_Customize_Manager
  27          */
  28         public $manager;
  29
  30         /**
  31          * All id_bases for widgets defined in core.
  32          *
  33          * @since 3.9.0
  34          * @access protected
  35          * @var array
  36          */
  37         protected $core_widget_id_bases = array(
  38                 'archives', 'calendar', 'categories', 'links', 'meta',
  39                 'nav_menu', 'pages', 'recent-comments', 'recent-posts',
  40                 'rss', 'search', 'tag_cloud', 'text',
  41         );
  42
  43         /**
  44          * @since 3.9.0
  45          * @access protected
  46          * @var array
  47          */
  48         protected $rendered_sidebars = array();
  49
  50         /**
  51          * @since 3.9.0
  52          * @access protected
  53          * @var array
  54          */
  55         protected $rendered_widgets = array();
  56
  57         /**
  58          * @since 3.9.0
  59          * @access protected
  60          * @var array
  61          */
  62         protected $old_sidebars_widgets = array();
  63
  64         /**
  65          * Mapping of setting type to setting ID pattern.
  66          *
  67          * @since 4.2.0
  68          * @access protected
  69          * @var array
  70          */
  71         protected $setting_id_patterns = array(
  72                 'widget_instance' => '/^(widget_.+?)(?:\[(\d+)\])?$/',
  73                 'sidebar_widgets' => '/^sidebars_widgets\[(.+?)\]$/',
  74         );
  75
  76         /**
  77          * Initial loader.
  78          *
  79          * @since 3.9.0
  80          * @access public
  81          *
  82          * @param WP_Customize_Manager $manager Customize manager bootstrap instance.
  83          */
  84         public function __construct( $manager ) {
  85                 $this->manager = $manager;
  86
  87                 add_filter( 'customize_dynamic_setting_args',          array( $this, 'filter_customize_dynamic_setting_args' ), 10, 2 );
  88                 add_action( 'after_setup_theme',                       array( $this, 'register_settings' ) );
  89                 add_action( 'wp_loaded',                               array( $this, 'override_sidebars_widgets_for_theme_switch' ) );
  90                 add_action( 'customize_controls_init',                 array( $this, 'customize_controls_init' ) );
  91                 add_action( 'customize_register',                      array( $this, 'schedule_customize_register' ), 1 );
  92                 add_action( 'customize_controls_enqueue_scripts',      array( $this, 'enqueue_scripts' ) );
  93                 add_action( 'customize_controls_print_styles',         array( $this, 'print_styles' ) );
  94                 add_action( 'customize_controls_print_scripts',        array( $this, 'print_scripts' ) );
  95                 add_action( 'customize_controls_print_footer_scripts', array( $this, 'print_footer_scripts' ) );
  96                 add_action( 'customize_controls_print_footer_scripts', array( $this, 'output_widget_control_templates' ) );
  97                 add_action( 'customize_preview_init',                  array( $this, 'customize_preview_init' ) );
  98                 add_filter( 'customize_refresh_nonces',                array( $this, 'refresh_nonces' ) );
  99
 100                 add_action( 'dynamic_sidebar',                         array( $this, 'tally_rendered_widgets' ) );
 101                 add_filter( 'is_active_sidebar',                       array( $this, 'tally_sidebars_via_is_active_sidebar_calls' ), 10, 2 );
 102                 add_filter( 'dynamic_sidebar_has_widgets',             array( $this, 'tally_sidebars_via_dynamic_sidebar_calls' ), 10, 2 );
 103         }
 104
 105         /**
 106          * Get the widget setting type given a setting ID.
 107          *
 108          * @since 4.2.0
 109          * @access protected
 110          *
 111          * @param $setting_id Setting ID.
 112          * @return string|null Setting type. Null otherwise.
 113          */
 114         protected function get_setting_type( $setting_id ) {
 115                 static $cache = array();
 116                 if ( isset( $cache[ $setting_id ] ) ) {
 117                         return $cache[ $setting_id ];
 118                 }
 119                 foreach ( $this->setting_id_patterns as $type => $pattern ) {
 120                         if ( preg_match( $pattern, $setting_id ) ) {
 121                                 $cache[ $setting_id ] = $type;
 122                                 return $type;
 123                         }
 124                 }
 125                 return null;
 126         }
 127
 128         /**
 129          * Inspect the incoming customized data for any widget settings, and dynamically add them up-front so widgets will be initialized properly.
 130          *
 131          * @since 4.2.0
 132          * @access public
 133          */
 134         public function register_settings() {
 135                 $widget_setting_ids = array();
 136                 $incoming_setting_ids = array_keys( $this->manager->unsanitized_post_values() );
 137                 foreach ( $incoming_setting_ids as $setting_id ) {
 138                         if ( ! is_null( $this->get_setting_type( $setting_id ) ) ) {
 139                                 $widget_setting_ids[] = $setting_id;
 140                         }
 141                 }
 142                 if ( $this->manager->doing_ajax( 'update-widget' ) && isset( $_REQUEST['widget-id'] ) ) {
 143                         $widget_setting_ids[] = $this->get_setting_id( wp_unslash( $_REQUEST['widget-id'] ) );
 144                 }
 145
 146                 $settings = $this->manager->add_dynamic_settings( array_unique( $widget_setting_ids ) );
 147
 148                 /*
 149                  * Preview settings right away so that widgets and sidebars will get registered properly.
 150                  * But don't do this if a customize_save because this will cause WP to think there is nothing
 151                  * changed that needs to be saved.
 152                  */
 153                 if ( ! $this->manager->doing_ajax( 'customize_save' ) ) {
 154                         foreach ( $settings as $setting ) {
 155                                 $setting->preview();
 156                         }
 157                 }
 158         }
 159
 160         /**
 161          * Determine the arguments for a dynamically-created setting.
 162          *
 163          * @since 4.2.0
 164          * @access public
 165          *
 166          * @param false|array $setting_args The arguments to the WP_Customize_Setting constructor.
 167          * @param string      $setting_id   ID for dynamic setting, usually coming from `$_POST['customized']`.
 168          * @return false|array Setting arguments, false otherwise.
 169          */
 170         public function filter_customize_dynamic_setting_args( $args, $setting_id ) {
 171                 if ( $this->get_setting_type( $setting_id ) ) {
 172                         $args = $this->get_setting_args( $setting_id );
 173                 }
 174                 return $args;
 175         }
 176
 177         /**
 178          * Get an unslashed post value or return a default.
 179          *
 180          * @since 3.9.0
 181          *
 182          * @access protected
 183          *
 184          * @param string $name    Post value.
 185          * @param mixed  $default Default post value.
 186          * @return mixed Unslashed post value or default value.
 187          */
 188         protected function get_post_value( $name, $default = null ) {
 189                 if ( ! isset( $_POST[ $name ] ) ) {
 190                         return $default;
 191                 }
 192
 193                 return wp_unslash( $_POST[ $name ] );
 194         }
 195
 196         /**
 197          * Override sidebars_widgets for theme switch.
 198          *
 199          * When switching a theme via the Customizer, supply any previously-configured
 200          * sidebars_widgets from the target theme as the initial sidebars_widgets
 201          * setting. Also store the old theme's existing settings so that they can
 202          * be passed along for storing in the sidebars_widgets theme_mod when the
 203          * theme gets switched.
 204          *
 205          * @since 3.9.0
 206          * @access public
 207          */
 208         public function override_sidebars_widgets_for_theme_switch() {
 209                 global $sidebars_widgets;
 210
 211                 if ( $this->manager->doing_ajax() || $this->manager->is_theme_active() ) {
 212                         return;
 213                 }
 214
 215                 $this->old_sidebars_widgets = wp_get_sidebars_widgets();
 216                 add_filter( 'customize_value_old_sidebars_widgets_data', array( $this, 'filter_customize_value_old_sidebars_widgets_data' ) );
 217
 218                 // retrieve_widgets() looks at the global $sidebars_widgets
 219                 $sidebars_widgets = $this->old_sidebars_widgets;
 220                 $sidebars_widgets = retrieve_widgets( 'customize' );
 221                 add_filter( 'option_sidebars_widgets', array( $this, 'filter_option_sidebars_widgets_for_theme_switch' ), 1 );
 222                 unset( $GLOBALS['_wp_sidebars_widgets'] ); // reset global cache var used by wp_get_sidebars_widgets()
 223         }
 224
 225         /**
 226          * Filter old_sidebars_widgets_data Customizer setting.
 227          *
 228          * When switching themes, filter the Customizer setting
 229          * old_sidebars_widgets_data to supply initial $sidebars_widgets before they
 230          * were overridden by retrieve_widgets(). The value for
 231          * old_sidebars_widgets_data gets set in the old theme's sidebars_widgets
 232          * theme_mod.
 233          *
 234          * @see WP_Customize_Widgets::handle_theme_switch()
 235          * @since 3.9.0
 236          * @access public
 237          *
 238          * @param array $old_sidebars_widgets
 239          */
 240         public function filter_customize_value_old_sidebars_widgets_data( $old_sidebars_widgets ) {
 241                 return $this->old_sidebars_widgets;
 242         }
 243
 244         /**
 245          * Filter sidebars_widgets option for theme switch.
 246          *
 247          * When switching themes, the retrieve_widgets() function is run when the
 248          * Customizer initializes, and then the new sidebars_widgets here get
 249          * supplied as the default value for the sidebars_widgets option.
 250          *
 251          * @see WP_Customize_Widgets::handle_theme_switch()
 252          * @since 3.9.0
 253          * @access public
 254          *
 255          * @param array $sidebars_widgets
 256          */
 257         public function filter_option_sidebars_widgets_for_theme_switch( $sidebars_widgets ) {
 258                 $sidebars_widgets = $GLOBALS['sidebars_widgets'];
 259                 $sidebars_widgets['array_version'] = 3;
 260                 return $sidebars_widgets;
 261         }
 262
 263         /**
 264          * Make sure all widgets get loaded into the Customizer.
 265          *
 266          * Note: these actions are also fired in wp_ajax_update_widget().
 267          *
 268          * @since 3.9.0
 269          * @access public
 270          */
 271         public function customize_controls_init() {
 272                 /** This action is documented in wp-admin/includes/ajax-actions.php */
 273                 do_action( 'load-widgets.php' );
 274
 275                 /** This action is documented in wp-admin/includes/ajax-actions.php */
 276                 do_action( 'widgets.php' );
 277
 278                 /** This action is documented in wp-admin/widgets.php */
 279                 do_action( 'sidebar_admin_setup' );
 280         }
 281
 282         /**
 283          * Ensure widgets are available for all types of previews.
 284          *
 285          * When in preview, hook to 'customize_register' for settings
 286          * after WordPress is loaded so that all filters have been
 287          * initialized (e.g. Widget Visibility).
 288          *
 289          * @since 3.9.0
 290          * @access public
 291          */
 292         public function schedule_customize_register() {
 293                 if ( is_admin() ) {
 294                         $this->customize_register();
 295                 } else {
 296                         add_action( 'wp', array( $this, 'customize_register' ) );
 297                 }
 298         }
 299
 300         /**
 301          * Register Customizer settings and controls for all sidebars and widgets.
 302          *
 303          * @since 3.9.0
 304          * @access public
 305          */
 306         public function customize_register() {
 307                 global $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_sidebars;
 308
 309                 $sidebars_widgets = array_merge(
 310                         array( 'wp_inactive_widgets' => array() ),
 311                         array_fill_keys( array_keys( $GLOBALS['wp_registered_sidebars'] ), array() ),
 312                         wp_get_sidebars_widgets()
 313                 );
 314
 315                 $new_setting_ids = array();
 316
 317                 /*
 318                  * Register a setting for all widgets, including those which are active,
 319                  * inactive, and orphaned since a widget may get suppressed from a sidebar
 320                  * via a plugin (like Widget Visibility).
 321                  */
 322                 foreach ( array_keys( $wp_registered_widgets ) as $widget_id ) {
 323                         $setting_id   = $this->get_setting_id( $widget_id );
 324                         $setting_args = $this->get_setting_args( $setting_id );
 325                         if ( ! $this->manager->get_setting( $setting_id ) ) {
 326                                 $this->manager->add_setting( $setting_id, $setting_args );
 327                         }
 328                         $new_setting_ids[] = $setting_id;
 329                 }
 330
 331                 /*
 332                  * Add a setting which will be supplied for the theme's sidebars_widgets
 333                  * theme_mod when the the theme is switched.
 334                  */
 335                 if ( ! $this->manager->is_theme_active() ) {
 336                         $setting_id = 'old_sidebars_widgets_data';
 337                         $setting_args = $this->get_setting_args( $setting_id, array(
 338                                 'type' => 'global_variable',
 339                                 'dirty' => true,
 340                         ) );
 341                         $this->manager->add_setting( $setting_id, $setting_args );
 342                 }
 343
 344                 $this->manager->add_panel( 'widgets', array(
 345                         'title'       => __( 'Widgets' ),
 346                         'description' => __( 'Widgets are independent sections of content that can be placed into widgetized areas provided by your theme (commonly called sidebars).' ),
 347                         'priority'    => 110,
 348                 ) );
 349
 350                 foreach ( $sidebars_widgets as $sidebar_id => $sidebar_widget_ids ) {
 351                         if ( empty( $sidebar_widget_ids ) ) {
 352                                 $sidebar_widget_ids = array();
 353                         }
 354
 355                         $is_registered_sidebar = isset( $GLOBALS['wp_registered_sidebars'][$sidebar_id] );
 356                         $is_inactive_widgets   = ( 'wp_inactive_widgets' === $sidebar_id );
 357                         $is_active_sidebar     = ( $is_registered_sidebar && ! $is_inactive_widgets );
 358
 359                         // Add setting for managing the sidebar's widgets.
 360                         if ( $is_registered_sidebar || $is_inactive_widgets ) {
 361                                 $setting_id   = sprintf( 'sidebars_widgets[%s]', $sidebar_id );
 362                                 $setting_args = $this->get_setting_args( $setting_id );
 363                                 if ( ! $this->manager->get_setting( $setting_id ) ) {
 364                                         if ( ! $this->manager->is_theme_active() ) {
 365                                                 $setting_args['dirty'] = true;
 366                                         }
 367                                         $this->manager->add_setting( $setting_id, $setting_args );
 368                                 }
 369                                 $new_setting_ids[] = $setting_id;
 370
 371                                 // Add section to contain controls.
 372                                 $section_id = sprintf( 'sidebar-widgets-%s', $sidebar_id );
 373                                 if ( $is_active_sidebar ) {
 374
 375                                         $section_args = array(
 376                                                 'title' => $GLOBALS['wp_registered_sidebars'][ $sidebar_id ]['name'],
 377                                                 'description' => $GLOBALS['wp_registered_sidebars'][ $sidebar_id ]['description'],
 378                                                 'priority' => array_search( $sidebar_id, array_keys( $wp_registered_sidebars ) ),
 379                                                 'panel' => 'widgets',
 380                                                 'sidebar_id' => $sidebar_id,
 381                                         );
 382
 383                                         /**
 384                                          * Filter Customizer widget section arguments for a given sidebar.
 385                                          *
 386                                          * @since 3.9.0
 387                                          *
 388                                          * @param array      $section_args Array of Customizer widget section arguments.
 389                                          * @param string     $section_id   Customizer section ID.
 390                                          * @param int|string $sidebar_id   Sidebar ID.
 391                                          */
 392                                         $section_args = apply_filters( 'customizer_widgets_section_args', $section_args, $section_id, $sidebar_id );
 393
 394                                         $section = new WP_Customize_Sidebar_Section( $this->manager, $section_id, $section_args );
 395                                         $this->manager->add_section( $section );
 396
 397                                         $control = new WP_Widget_Area_Customize_Control( $this->manager, $setting_id, array(
 398                                                 'section'    => $section_id,
 399                                                 'sidebar_id' => $sidebar_id,
 400                                                 'priority'   => count( $sidebar_widget_ids ), // place 'Add Widget' and 'Reorder' buttons at end.
 401                                         ) );
 402                                         $new_setting_ids[] = $setting_id;
 403
 404                                         $this->manager->add_control( $control );
 405                                 }
 406                         }
 407
 408                         // Add a control for each active widget (located in a sidebar).
 409                         foreach ( $sidebar_widget_ids as $i => $widget_id ) {
 410
 411                                 // Skip widgets that may have gone away due to a plugin being deactivated.
 412                                 if ( ! $is_active_sidebar || ! isset( $GLOBALS['wp_registered_widgets'][$widget_id] ) ) {
 413                                         continue;
 414                                 }
 415
 416                                 $registered_widget = $GLOBALS['wp_registered_widgets'][$widget_id];
 417                                 $setting_id        = $this->get_setting_id( $widget_id );
 418                                 $id_base           = $GLOBALS['wp_registered_widget_controls'][$widget_id]['id_base'];
 419
 420                                 $control = new WP_Widget_Form_Customize_Control( $this->manager, $setting_id, array(
 421                                         'label'          => $registered_widget['name'],
 422                                         'section'        => $section_id,
 423                                         'sidebar_id'     => $sidebar_id,
 424                                         'widget_id'      => $widget_id,
 425                                         'widget_id_base' => $id_base,
 426                                         'priority'       => $i,
 427                                         'width'          => $wp_registered_widget_controls[$widget_id]['width'],
 428                                         'height'         => $wp_registered_widget_controls[$widget_id]['height'],
 429                                         'is_wide'        => $this->is_wide_widget( $widget_id ),
 430                                 ) );
 431                                 $this->manager->add_control( $control );
 432                         }
 433                 }
 434
 435                 if ( ! $this->manager->doing_ajax( 'customize_save' ) ) {
 436                         foreach ( $new_setting_ids as $new_setting_id ) {
 437                                 $this->manager->get_setting( $new_setting_id )->preview();
 438                         }
 439                 }
 440
 441                 add_filter( 'sidebars_widgets', array( $this, 'preview_sidebars_widgets' ), 1 );
 442         }
 443
 444         /**
 445          * Covert a widget_id into its corresponding Customizer setting ID (option name).
 446          *
 447          * @since 3.9.0
 448          * @access public
 449          *
 450          * @param string $widget_id Widget ID.
 451          * @return string Maybe-parsed widget ID.
 452          */
 453         public function get_setting_id( $widget_id ) {
 454                 $parsed_widget_id = $this->parse_widget_id( $widget_id );
 455                 $setting_id       = sprintf( 'widget_%s', $parsed_widget_id['id_base'] );
 456
 457                 if ( ! is_null( $parsed_widget_id['number'] ) ) {
 458                         $setting_id .= sprintf( '[%d]', $parsed_widget_id['number'] );
 459                 }
 460                 return $setting_id;
 461         }
 462
 463         /**
 464          * Determine whether the widget is considered "wide".
 465          *
 466          * Core widgets which may have controls wider than 250, but can
 467          * still be shown in the narrow Customizer panel. The RSS and Text
 468          * widgets in Core, for example, have widths of 400 and yet they
 469          * still render fine in the Customizer panel. This method will
 470          * return all Core widgets as being not wide, but this can be
 471          * overridden with the is_wide_widget_in_customizer filter.
 472          *
 473          * @since 3.9.0
 474          * @access public
 475          *
 476          * @param string $widget_id Widget ID.
 477          * @return bool Whether or not the widget is a "wide" widget.
 478          */
 479         public function is_wide_widget( $widget_id ) {
 480                 global $wp_registered_widget_controls;
 481
 482                 $parsed_widget_id = $this->parse_widget_id( $widget_id );
 483                 $width            = $wp_registered_widget_controls[$widget_id]['width'];
 484                 $is_core          = in_array( $parsed_widget_id['id_base'], $this->core_widget_id_bases );
 485                 $is_wide          = ( $width > 250 && ! $is_core );
 486
 487                 /**
 488                  * Filter whether the given widget is considered "wide".
 489                  *
 490                  * @since 3.9.0
 491                  *
 492                  * @param bool   $is_wide   Whether the widget is wide, Default false.
 493                  * @param string $widget_id Widget ID.
 494                  */
 495                 return apply_filters( 'is_wide_widget_in_customizer', $is_wide, $widget_id );
 496         }
 497
 498         /**
 499          * Covert a widget ID into its id_base and number components.
 500          *
 501          * @since 3.9.0
 502          * @access public
 503          *
 504          * @param string $widget_id Widget ID.
 505          * @return array Array containing a widget's id_base and number components.
 506          */
 507         public function parse_widget_id( $widget_id ) {
 508                 $parsed = array(
 509                         'number' => null,
 510                         'id_base' => null,
 511                 );
 512
 513                 if ( preg_match( '/^(.+)-(\d+)$/', $widget_id, $matches ) ) {
 514                         $parsed['id_base'] = $matches[1];
 515                         $parsed['number']  = intval( $matches[2] );
 516                 } else {
 517                         // likely an old single widget
 518                         $parsed['id_base'] = $widget_id;
 519                 }
 520                 return $parsed;
 521         }
 522
 523         /**
 524          * Convert a widget setting ID (option path) to its id_base and number components.
 525          *
 526          * @since 3.9.0
 527          * @access public
 528          *
 529          * @param string $setting_id Widget setting ID.
 530          * @return WP_Error|array Array containing a widget's id_base and number components,
 531          *                        or a WP_Error object.
 532          */
 533         public function parse_widget_setting_id( $setting_id ) {
 534                 if ( ! preg_match( '/^(widget_(.+?))(?:\[(\d+)\])?$/', $setting_id, $matches ) ) {
 535                         return new WP_Error( 'widget_setting_invalid_id' );
 536                 }
 537
 538                 $id_base = $matches[2];
 539                 $number  = isset( $matches[3] ) ? intval( $matches[3] ) : null;
 540
 541                 return compact( 'id_base', 'number' );
 542         }
 543
 544         /**
 545          * Call admin_print_styles-widgets.php and admin_print_styles hooks to
 546          * allow custom styles from plugins.
 547          *
 548          * @since 3.9.0
 549          * @access public
 550          */
 551         public function print_styles() {
 552                 /** This action is documented in wp-admin/admin-header.php */
 553                 do_action( 'admin_print_styles-widgets.php' );
 554
 555                 /** This action is documented in wp-admin/admin-header.php */
 556                 do_action( 'admin_print_styles' );
 557         }
 558
 559         /**
 560          * Call admin_print_scripts-widgets.php and admin_print_scripts hooks to
 561          * allow custom scripts from plugins.
 562          *
 563          * @since 3.9.0
 564          * @access public
 565          */
 566         public function print_scripts() {
 567                 /** This action is documented in wp-admin/admin-header.php */
 568                 do_action( 'admin_print_scripts-widgets.php' );
 569
 570                 /** This action is documented in wp-admin/admin-header.php */
 571                 do_action( 'admin_print_scripts' );
 572         }
 573
 574         /**
 575          * Enqueue scripts and styles for Customizer panel and export data to JavaScript.
 576          *
 577          * @since 3.9.0
 578          * @access public
 579          */
 580         public function enqueue_scripts() {
 581                 wp_enqueue_style( 'customize-widgets' );
 582                 wp_enqueue_script( 'customize-widgets' );
 583
 584                 /** This action is documented in wp-admin/admin-header.php */
 585                 do_action( 'admin_enqueue_scripts', 'widgets.php' );
 586
 587                 /*
 588                  * Export available widgets with control_tpl removed from model
 589                  * since plugins need templates to be in the DOM.
 590                  */
 591                 $available_widgets = array();
 592
 593                 foreach ( $this->get_available_widgets() as $available_widget ) {
 594                         unset( $available_widget['control_tpl'] );
 595                         $available_widgets[] = $available_widget;
 596                 }
 597
 598                 $widget_reorder_nav_tpl = sprintf(
 599                         '<div class="widget-reorder-nav"><span class="move-widget" tabindex="0">%1$s</span><span class="move-widget-down" tabindex="0">%2$s</span><span class="move-widget-up" tabindex="0">%3$s</span></div>',
 600                         __( 'Move to another area&hellip;' ),
 601                         __( 'Move down' ),
 602                         __( 'Move up' )
 603                 );
 604
 605                 $move_widget_area_tpl = str_replace(
 606                         array( '{description}', '{btn}' ),
 607                         array(
 608                                 __( 'Select an area to move this widget into:' ),
 609                                 _x( 'Move', 'Move widget' ),
 610                         ),
 611                         '<div class="move-widget-area">
 612                                 <p class="description">{description}</p>
 613                                 <ul class="widget-area-select">
 614                                         <% _.each( sidebars, function ( sidebar ){ %>
 615                                                 <li class="" data-id="<%- sidebar.id %>" title="<%- sidebar.description %>" tabindex="0"><%- sidebar.name %></li>
 616                                         <% }); %>
 617                                 </ul>
 618                                 <div class="move-widget-actions">
 619                                         <button class="move-widget-btn button-secondary" type="button">{btn}</button>
 620                                 </div>
 621                         </div>'
 622                 );
 623
 624                 global $wp_scripts;
 625
 626                 $settings = array(
 627                         'nonce'                => wp_create_nonce( 'update-widget' ),
 628                         'registeredSidebars'   => array_values( $GLOBALS['wp_registered_sidebars'] ),
 629                         'registeredWidgets'    => $GLOBALS['wp_registered_widgets'],
 630                         'availableWidgets'     => $available_widgets, // @todo Merge this with registered_widgets
 631                         'l10n' => array(
 632                                 'saveBtnLabel'     => __( 'Apply' ),
 633                                 'saveBtnTooltip'   => __( 'Save and preview changes before publishing them.' ),
 634                                 'removeBtnLabel'   => __( 'Remove' ),
 635                                 'removeBtnTooltip' => __( 'Trash widget by moving it to the inactive widgets sidebar.' ),
 636                                 'error'            => __( 'An error has occurred. Please reload the page and try again.' ),
 637                                 'widgetMovedUp'    => __( 'Widget moved up' ),
 638                                 'widgetMovedDown'  => __( 'Widget moved down' ),
 639                         ),
 640                         'tpl' => array(
 641                                 'widgetReorderNav' => $widget_reorder_nav_tpl,
 642                                 'moveWidgetArea'   => $move_widget_area_tpl,
 643                         ),
 644                 );
 645
 646                 foreach ( $settings['registeredWidgets'] as &$registered_widget ) {
 647                         unset( $registered_widget['callback'] ); // may not be JSON-serializeable
 648                 }
 649
 650                 $wp_scripts->add_data(
 651                         'customize-widgets',
 652                         'data',
 653                         sprintf( 'var _wpCustomizeWidgetsSettings = %s;', wp_json_encode( $settings ) )
 654                 );
 655         }
 656
 657         /**
 658          * Render the widget form control templates into the DOM.
 659          *
 660          * @since 3.9.0
 661          * @access public
 662          */
 663         public function output_widget_control_templates() {
 664                 ?>
 665                 <div id="widgets-left"><!-- compatibility with JS which looks for widget templates here -->
 666                 <div id="available-widgets">
 667                         <div id="available-widgets-filter">
 668                                 <label class="screen-reader-text" for="widgets-search"><?php _e( 'Search Widgets' ); ?></label>
 669                                 <input type="search" id="widgets-search" placeholder="<?php esc_attr_e( 'Search widgets&hellip;' ) ?>" />
 670                         </div>
 671                         <div id="available-widgets-list">
 672                         <?php foreach ( $this->get_available_widgets() as $available_widget ): ?>
 673                                 <div id="widget-tpl-<?php echo esc_attr( $available_widget['id'] ) ?>" data-widget-id="<?php echo esc_attr( $available_widget['id'] ) ?>" class="widget-tpl <?php echo esc_attr( $available_widget['id'] ) ?>" tabindex="0">
 674                                         <?php echo $available_widget['control_tpl']; ?>
 675                                 </div>
 676                         <?php endforeach; ?>
 677                         </div><!-- #available-widgets-list -->
 678                 </div><!-- #available-widgets -->
 679                 </div><!-- #widgets-left -->
 680                 <?php
 681         }
 682
 683         /**
 684          * Call admin_print_footer_scripts and admin_print_scripts hooks to
 685          * allow custom scripts from plugins.
 686          *
 687          * @since 3.9.0
 688          * @access public
 689          */
 690         public function print_footer_scripts() {
 691                 /** This action is documented in wp-admin/admin-footer.php */
 692                 do_action( 'admin_print_footer_scripts' );
 693
 694                 /** This action is documented in wp-admin/admin-footer.php */
 695                 do_action( 'admin_footer-widgets.php' );
 696         }
 697
 698         /**
 699          * Get common arguments to supply when constructing a Customizer setting.
 700          *
 701          * @since 3.9.0
 702          * @access public
 703          *
 704          * @param string $id        Widget setting ID.
 705          * @param array  $overrides Array of setting overrides.
 706          * @return array Possibly modified setting arguments.
 707          */
 708         public function get_setting_args( $id, $overrides = array() ) {
 709                 $args = array(
 710                         'type'       => 'option',
 711                         'capability' => 'edit_theme_options',
 712                         'transport'  => 'refresh',
 713                         'default'    => array(),
 714                 );
 715
 716                 if ( preg_match( $this->setting_id_patterns['sidebar_widgets'], $id, $matches ) ) {
 717                         $args['sanitize_callback'] = array( $this, 'sanitize_sidebar_widgets' );
 718                         $args['sanitize_js_callback'] = array( $this, 'sanitize_sidebar_widgets_js_instance' );
 719                 } else if ( preg_match( $this->setting_id_patterns['widget_instance'], $id, $matches ) ) {
 720                         $args['sanitize_callback'] = array( $this, 'sanitize_widget_instance' );
 721                         $args['sanitize_js_callback'] = array( $this, 'sanitize_widget_js_instance' );
 722                 }
 723
 724                 $args = array_merge( $args, $overrides );
 725
 726                 /**
 727                  * Filter the common arguments supplied when constructing a Customizer setting.
 728                  *
 729                  * @since 3.9.0
 730                  *
 731                  * @see WP_Customize_Setting
 732                  *
 733                  * @param array  $args Array of Customizer setting arguments.
 734                  * @param string $id   Widget setting ID.
 735                  */
 736                 return apply_filters( 'widget_customizer_setting_args', $args, $id );
 737         }
 738
 739         /**
 740          * Make sure that sidebar widget arrays only ever contain widget IDS.
 741          *
 742          * Used as the 'sanitize_callback' for each $sidebars_widgets setting.
 743          *
 744          * @since 3.9.0
 745          * @access public
 746          *
 747          * @param array $widget_ids Array of widget IDs.
 748          * @return array Array of sanitized widget IDs.
 749          */
 750         public function sanitize_sidebar_widgets( $widget_ids ) {
 751                 $widget_ids = array_map( 'strval', (array) $widget_ids );
 752                 $sanitized_widget_ids = array();
 753                 foreach ( $widget_ids as $widget_id ) {
 754                         $sanitized_widget_ids[] = preg_replace( '/[^a-z0-9_\-]/', '', $widget_id );
 755                 }
 756                 return $sanitized_widget_ids;
 757         }
 758
 759         /**
 760          * Build up an index of all available widgets for use in Backbone models.
 761          *
 762          * @since 3.9.0
 763          * @access public
 764          *
 765          * @see wp_list_widgets()
 766          *
 767          * @return array List of available widgets.
 768          */
 769         public function get_available_widgets() {
 770                 static $available_widgets = array();
 771                 if ( ! empty( $available_widgets ) ) {
 772                         return $available_widgets;
 773                 }
 774
 775                 global $wp_registered_widgets, $wp_registered_widget_controls;
 776                 require_once ABSPATH . '/wp-admin/includes/widgets.php'; // for next_widget_id_number()
 777
 778                 $sort = $wp_registered_widgets;
 779                 usort( $sort, array( $this, '_sort_name_callback' ) );
 780                 $done = array();
 781
 782                 foreach ( $sort as $widget ) {
 783                         if ( in_array( $widget['callback'], $done, true ) ) { // We already showed this multi-widget
 784                                 continue;
 785                         }
 786
 787                         $sidebar = is_active_widget( $widget['callback'], $widget['id'], false, false );
 788                         $done[]  = $widget['callback'];
 789
 790                         if ( ! isset( $widget['params'][0] ) ) {
 791                                 $widget['params'][0] = array();
 792                         }
 793
 794                         $available_widget = $widget;
 795                         unset( $available_widget['callback'] ); // not serializable to JSON
 796
 797                         $args = array(
 798                                 'widget_id'   => $widget['id'],
 799                                 'widget_name' => $widget['name'],
 800                                 '_display'    => 'template',
 801                         );
 802
 803                         $is_disabled     = false;
 804                         $is_multi_widget = ( isset( $wp_registered_widget_controls[$widget['id']]['id_base'] ) && isset( $widget['params'][0]['number'] ) );
 805                         if ( $is_multi_widget ) {
 806                                 $id_base            = $wp_registered_widget_controls[$widget['id']]['id_base'];
 807                                 $args['_temp_id']   = "$id_base-__i__";
 808                                 $args['_multi_num'] = next_widget_id_number( $id_base );
 809                                 $args['_add']       = 'multi';
 810                         } else {
 811                                 $args['_add'] = 'single';
 812
 813                                 if ( $sidebar && 'wp_inactive_widgets' !== $sidebar ) {
 814                                         $is_disabled = true;
 815                                 }
 816                                 $id_base = $widget['id'];
 817                         }
 818
 819                         $list_widget_controls_args = wp_list_widget_controls_dynamic_sidebar( array( 0 => $args, 1 => $widget['params'][0] ) );
 820                         $control_tpl = $this->get_widget_control( $list_widget_controls_args );
 821
 822                         // The properties here are mapped to the Backbone Widget model.
 823                         $available_widget = array_merge( $available_widget, array(
 824                                 'temp_id'      => isset( $args['_temp_id'] ) ? $args['_temp_id'] : null,
 825                                 'is_multi'     => $is_multi_widget,
 826                                 'control_tpl'  => $control_tpl,
 827                                 'multi_number' => ( $args['_add'] === 'multi' ) ? $args['_multi_num'] : false,
 828                                 'is_disabled'  => $is_disabled,
 829                                 'id_base'      => $id_base,
 830                                 'transport'    => 'refresh',
 831                                 'width'        => $wp_registered_widget_controls[$widget['id']]['width'],
 832                                 'height'       => $wp_registered_widget_controls[$widget['id']]['height'],
 833                                 'is_wide'      => $this->is_wide_widget( $widget['id'] ),
 834                         ) );
 835
 836                         $available_widgets[] = $available_widget;
 837                 }
 838
 839                 return $available_widgets;
 840         }
 841
 842         /**
 843          * Naturally order available widgets by name.
 844          *
 845          * @since 3.9.0
 846          * @static
 847          * @access protected
 848          *
 849          * @param array $widget_a The first widget to compare.
 850          * @param array $widget_b The second widget to compare.
 851          * @return int Reorder position for the current widget comparison.
 852          */
 853         protected function _sort_name_callback( $widget_a, $widget_b ) {
 854                 return strnatcasecmp( $widget_a['name'], $widget_b['name'] );
 855         }
 856
 857         /**
 858          * Get the widget control markup.
 859          *
 860          * @since 3.9.0
 861          * @access public
 862          *
 863          * @param array $args Widget control arguments.
 864          * @return string Widget control form HTML markup.
 865          */
 866         public function get_widget_control( $args ) {
 867                 ob_start();
 868
 869                 call_user_func_array( 'wp_widget_control', $args );
 870                 $replacements = array(
 871                         '<form method="post">' => '<div class="form">',
 872                         '</form>' => '</div><!-- .form -->',
 873                 );
 874
 875                 $control_tpl = ob_get_clean();
 876
 877                 $control_tpl = str_replace( array_keys( $replacements ), array_values( $replacements ), $control_tpl );
 878
 879                 return $control_tpl;
 880         }
 881
 882         /**
 883          * Add hooks for the Customizer preview.
 884          *
 885          * @since 3.9.0
 886          * @access public
 887          */
 888         public function customize_preview_init() {
 889                 add_action( 'wp_enqueue_scripts', array( $this, 'customize_preview_enqueue' ) );
 890                 add_action( 'wp_print_styles',    array( $this, 'print_preview_css' ), 1 );
 891                 add_action( 'wp_footer',          array( $this, 'export_preview_data' ), 20 );
 892         }
 893
 894         /**
 895          * Refresh nonce for widget updates.
 896          *
 897          * @since 4.2.0
 898          * @access public
 899          *
 900          * @param  array $nonces Array of nonces.
 901          * @return array $nonces Array of nonces.
 902          */
 903         public function refresh_nonces( $nonces ) {
 904                 $nonces['update-widget'] = wp_create_nonce( 'update-widget' );
 905                 return $nonces;
 906         }
 907
 908         /**
 909          * When previewing, make sure the proper previewing widgets are used.
 910          *
 911          * Because wp_get_sidebars_widgets() gets called early at init
 912          * (via wp_convert_widget_settings()) and can set global variable
 913          * $_wp_sidebars_widgets to the value of get_option( 'sidebars_widgets' )
 914          * before the Customizer preview filter is added, we have to reset
 915          * it after the filter has been added.
 916          *
 917          * @since 3.9.0
 918          * @access public
 919          *
 920          * @param array $sidebars_widgets List of widgets for the current sidebar.
 921          */
 922         public function preview_sidebars_widgets( $sidebars_widgets ) {
 923                 $sidebars_widgets = get_option( 'sidebars_widgets' );
 924
 925                 unset( $sidebars_widgets['array_version'] );
 926                 return $sidebars_widgets;
 927         }
 928
 929         /**
 930          * Enqueue scripts for the Customizer preview.
 931          *
 932          * @since 3.9.0
 933          * @access public
 934          */
 935         public function customize_preview_enqueue() {
 936                 wp_enqueue_script( 'customize-preview-widgets' );
 937         }
 938
 939         /**
 940          * Insert default style for highlighted widget at early point so theme
 941          * stylesheet can override.
 942          *
 943          * @since 3.9.0
 944          * @access public
 945          *
 946          * @action wp_print_styles
 947          */
 948         public function print_preview_css() {
 949                 ?>
 950                 <style>
 951                 .widget-customizer-highlighted-widget {
 952                         outline: none;
 953                         -webkit-box-shadow: 0 0 2px rgba(30,140,190,0.8);
 954                         box-shadow: 0 0 2px rgba(30,140,190,0.8);
 955                         position: relative;
 956                         z-index: 1;
 957                 }
 958                 </style>
 959                 <?php
 960         }
 961
 962         /**
 963          * At the very end of the page, at the very end of the wp_footer,
 964          * communicate the sidebars that appeared on the page.
 965          *
 966          * @since 3.9.0
 967          * @access public
 968          */
 969         public function export_preview_data() {
 970
 971                 // Prepare Customizer settings to pass to JavaScript.
 972                 $settings = array(
 973                         'renderedSidebars'   => array_fill_keys( array_unique( $this->rendered_sidebars ), true ),
 974                         'renderedWidgets'    => array_fill_keys( array_keys( $this->rendered_widgets ), true ),
 975                         'registeredSidebars' => array_values( $GLOBALS['wp_registered_sidebars'] ),
 976                         'registeredWidgets'  => $GLOBALS['wp_registered_widgets'],
 977                         'l10n'               => array(
 978                                 'widgetTooltip' => __( 'Shift-click to edit this widget.' ),
 979                         ),
 980                 );
 981                 foreach ( $settings['registeredWidgets'] as &$registered_widget ) {
 982                         unset( $registered_widget['callback'] ); // may not be JSON-serializeable
 983                 }
 984
 985                 ?>
 986                 <script type="text/javascript">
 987                         var _wpWidgetCustomizerPreviewSettings = <?php echo wp_json_encode( $settings ); ?>;
 988                 </script>
 989                 <?php
 990         }
 991
 992         /**
 993          * Keep track of the widgets that were rendered.
 994          *
 995          * @since 3.9.0
 996          * @access public
 997          *
 998          * @param array $widget Rendered widget to tally.
 999          */
1000         public function tally_rendered_widgets( $widget ) {
1001                 $this->rendered_widgets[ $widget['id'] ] = true;
1002         }
1003
1004         /**
1005          * Determine if a widget is rendered on the page.
1006          *
1007          * @since 4.0.0
1008          * @access public
1009          *
1010          * @param string $widget_id Widget ID to check.
1011          * @return bool Whether the widget is rendered.
1012          */
1013         public function is_widget_rendered( $widget_id ) {
1014                 return in_array( $widget_id, $this->rendered_widgets );
1015         }
1016
1017         /**
1018          * Determine if a sidebar is rendered on the page.
1019          *
1020          * @since 4.0.0
1021          * @access public
1022          *
1023          * @param string $sidebar_id Sidebar ID to check.
1024          * @return bool Whether the sidebar is rendered.
1025          */
1026         public function is_sidebar_rendered( $sidebar_id ) {
1027                 return in_array( $sidebar_id, $this->rendered_sidebars );
1028         }
1029
1030         /**
1031          * Tally the sidebars rendered via is_active_sidebar().
1032          *
1033          * Keep track of the times that is_active_sidebar() is called
1034          * in the template, and assume that this means that the sidebar
1035          * would be rendered on the template if there were widgets
1036          * populating it.
1037          *
1038          * @since 3.9.0
1039          * @access public
1040          *
1041          * @param bool   $is_active  Whether the sidebar is active.
1042          * @param string $sidebar_id Sidebar ID.
1043          */
1044         public function tally_sidebars_via_is_active_sidebar_calls( $is_active, $sidebar_id ) {
1045                 if ( isset( $GLOBALS['wp_registered_sidebars'][$sidebar_id] ) ) {
1046                         $this->rendered_sidebars[] = $sidebar_id;
1047                 }
1048                 /*
1049                  * We may need to force this to true, and also force-true the value
1050                  * for 'dynamic_sidebar_has_widgets' if we want to ensure that there
1051                  * is an area to drop widgets into, if the sidebar is empty.
1052                  */
1053                 return $is_active;
1054         }
1055
1056         /**
1057          * Tally the sidebars rendered via dynamic_sidebar().
1058          *
1059          * Keep track of the times that dynamic_sidebar() is called in the template,
1060          * and assume this means the sidebar would be rendered on the template if
1061          * there were widgets populating it.
1062          *
1063          * @since 3.9.0
1064          * @access public
1065          *
1066          * @param bool   $has_widgets Whether the current sidebar has widgets.
1067          * @param string $sidebar_id  Sidebar ID.
1068          */
1069         public function tally_sidebars_via_dynamic_sidebar_calls( $has_widgets, $sidebar_id ) {
1070                 if ( isset( $GLOBALS['wp_registered_sidebars'][$sidebar_id] ) ) {
1071                         $this->rendered_sidebars[] = $sidebar_id;
1072                 }
1073
1074                 /*
1075                  * We may need to force this to true, and also force-true the value
1076                  * for 'is_active_sidebar' if we want to ensure there is an area to
1077                  * drop widgets into, if the sidebar is empty.
1078                  */
1079                 return $has_widgets;
1080         }
1081
1082         /**
1083          * Get MAC for a serialized widget instance string.
1084          *
1085          * Allows values posted back from JS to be rejected if any tampering of the
1086          * data has occurred.
1087          *
1088          * @since 3.9.0
1089          * @access protected
1090          *
1091          * @param string $serialized_instance Widget instance.
1092          * @return string MAC for serialized widget instance.
1093          */
1094         protected function get_instance_hash_key( $serialized_instance ) {
1095                 return wp_hash( $serialized_instance );
1096         }
1097
1098         /**
1099          * Sanitize a widget instance.
1100          *
1101          * Unserialize the JS-instance for storing in the options. It's important
1102          * that this filter only get applied to an instance once.
1103          *
1104          * @since 3.9.0
1105          * @access public
1106          *
1107          * @param array $value Widget instance to sanitize.
1108          * @return array Sanitized widget instance.
1109          */
1110         public function sanitize_widget_instance( $value ) {
1111                 if ( $value === array() ) {
1112                         return $value;
1113                 }
1114
1115                 if ( empty( $value['is_widget_customizer_js_value'] )
1116                         || empty( $value['instance_hash_key'] )
1117                         || empty( $value['encoded_serialized_instance'] ) )
1118                 {
1119                         return null;
1120                 }
1121
1122                 $decoded = base64_decode( $value['encoded_serialized_instance'], true );
1123                 if ( false === $decoded ) {
1124                         return null;
1125                 }
1126
1127                 if ( $this->get_instance_hash_key( $decoded ) !== $value['instance_hash_key'] ) {
1128                         return null;
1129                 }
1130
1131                 $instance = unserialize( $decoded );
1132                 if ( false === $instance ) {
1133                         return null;
1134                 }
1135
1136                 return $instance;
1137         }
1138
1139         /**
1140          * Convert widget instance into JSON-representable format.
1141          *
1142          * @since 3.9.0
1143          * @access public
1144          *
1145          * @param array $value Widget instance to convert to JSON.
1146          * @return array JSON-converted widget instance.
1147          */
1148         public function sanitize_widget_js_instance( $value ) {
1149                 if ( empty( $value['is_widget_customizer_js_value'] ) ) {
1150                         $serialized = serialize( $value );
1151
1152                         $value = array(
1153                                 'encoded_serialized_instance'   => base64_encode( $serialized ),
1154                                 'title'                         => empty( $value['title'] ) ? '' : $value['title'],
1155                                 'is_widget_customizer_js_value' => true,
1156                                 'instance_hash_key'             => $this->get_instance_hash_key( $serialized ),
1157                         );
1158                 }
1159                 return $value;
1160         }
1161
1162         /**
1163          * Strip out widget IDs for widgets which are no longer registered.
1164          *
1165          * One example where this might happen is when a plugin orphans a widget
1166          * in a sidebar upon deactivation.
1167          *
1168          * @since 3.9.0
1169          * @access public
1170          *
1171          * @param array $widget_ids List of widget IDs.
1172          * @return array Parsed list of widget IDs.
1173          */
1174         public function sanitize_sidebar_widgets_js_instance( $widget_ids ) {
1175                 global $wp_registered_widgets;
1176                 $widget_ids = array_values( array_intersect( $widget_ids, array_keys( $wp_registered_widgets ) ) );
1177                 return $widget_ids;
1178         }
1179
1180         /**
1181          * Find and invoke the widget update and control callbacks.
1182          *
1183          * Requires that $_POST be populated with the instance data.
1184          *
1185          * @since 3.9.0
1186          * @access public
1187          *
1188          * @param  string $widget_id Widget ID.
1189          * @return WP_Error|array Array containing the updated widget information.
1190          *                        A WP_Error object, otherwise.
1191          */
1192         public function call_widget_update( $widget_id ) {
1193                 global $wp_registered_widget_updates, $wp_registered_widget_controls;
1194
1195                 $this->start_capturing_option_updates();
1196                 $parsed_id   = $this->parse_widget_id( $widget_id );
1197                 $option_name = 'widget_' . $parsed_id['id_base'];
1198
1199                 /*
1200                  * If a previously-sanitized instance is provided, populate the input vars
1201                  * with its values so that the widget update callback will read this instance
1202                  */
1203                 $added_input_vars = array();
1204                 if ( ! empty( $_POST['sanitized_widget_setting'] ) ) {
1205                         $sanitized_widget_setting = json_decode( $this->get_post_value( 'sanitized_widget_setting' ), true );
1206                         if ( false === $sanitized_widget_setting ) {
1207                                 $this->stop_capturing_option_updates();
1208                                 return new WP_Error( 'widget_setting_malformed' );
1209                         }
1210
1211                         $instance = $this->sanitize_widget_instance( $sanitized_widget_setting );
1212                         if ( is_null( $instance ) ) {
1213                                 $this->stop_capturing_option_updates();
1214                                 return new WP_Error( 'widget_setting_unsanitized' );
1215                         }
1216
1217                         if ( ! is_null( $parsed_id['number'] ) ) {
1218                                 $value = array();
1219                                 $value[$parsed_id['number']] = $instance;
1220                                 $key = 'widget-' . $parsed_id['id_base'];
1221                                 $_REQUEST[$key] = $_POST[$key] = wp_slash( $value );
1222                                 $added_input_vars[] = $key;
1223                         } else {
1224                                 foreach ( $instance as $key => $value ) {
1225                                         $_REQUEST[$key] = $_POST[$key] = wp_slash( $value );
1226                                         $added_input_vars[] = $key;
1227                                 }
1228                         }
1229                 }
1230
1231                 // Invoke the widget update callback.
1232                 foreach ( (array) $wp_registered_widget_updates as $name => $control ) {
1233                         if ( $name === $parsed_id['id_base'] && is_callable( $control['callback'] ) ) {
1234                                 ob_start();
1235                                 call_user_func_array( $control['callback'], $control['params'] );
1236                                 ob_end_clean();
1237                                 break;
1238                         }
1239                 }
1240
1241                 // Clean up any input vars that were manually added
1242                 foreach ( $added_input_vars as $key ) {
1243                         unset( $_POST[ $key ] );
1244                         unset( $_REQUEST[ $key ] );
1245                 }
1246
1247                 // Make sure the expected option was updated.
1248                 if ( 0 !== $this->count_captured_options() ) {
1249                         if ( $this->count_captured_options() > 1 ) {
1250                                 $this->stop_capturing_option_updates();
1251                                 return new WP_Error( 'widget_setting_too_many_options' );
1252                         }
1253
1254                         $updated_option_name = key( $this->get_captured_options() );
1255                         if ( $updated_option_name !== $option_name ) {
1256                                 $this->stop_capturing_option_updates();
1257                                 return new WP_Error( 'widget_setting_unexpected_option' );
1258                         }
1259                 }
1260
1261                 // Obtain the widget instance.
1262                 $option = $this->get_captured_option( $option_name );
1263                 if ( null !== $parsed_id['number'] ) {
1264                         $instance = $option[ $parsed_id['number'] ];
1265                 } else {
1266                         $instance = $option;
1267                 }
1268
1269                 /*
1270                  * Override the incoming $_POST['customized'] for a newly-created widget's
1271                  * setting with the new $instance so that the preview filter currently
1272                  * in place from WP_Customize_Setting::preview() will use this value
1273                  * instead of the default widget instance value (an empty array).
1274                  */
1275                 $setting_id = $this->get_setting_id( $widget_id );
1276                 $this->manager->set_post_value( $setting_id, $instance );
1277
1278                 // Obtain the widget control with the updated instance in place.
1279                 ob_start();
1280                 $form = $wp_registered_widget_controls[ $widget_id ];
1281                 if ( $form ) {
1282                         call_user_func_array( $form['callback'], $form['params'] );
1283                 }
1284                 $form = ob_get_clean();
1285
1286                 $this->stop_capturing_option_updates();
1287
1288                 return compact( 'instance', 'form' );
1289         }
1290
1291         /**
1292          * Update widget settings asynchronously.
1293          *
1294          * Allows the Customizer to update a widget using its form, but return the new
1295          * instance info via Ajax instead of saving it to the options table.
1296          *
1297          * Most code here copied from wp_ajax_save_widget()
1298          *
1299          * @since 3.9.0
1300          * @access public
1301          *
1302          * @see wp_ajax_save_widget()
1303          *
1304          */
1305         public function wp_ajax_update_widget() {
1306
1307                 if ( ! is_user_logged_in() ) {
1308                         wp_die( 0 );
1309                 }
1310
1311                 check_ajax_referer( 'update-widget', 'nonce' );
1312
1313                 if ( ! current_user_can( 'edit_theme_options' ) ) {
1314                         wp_die( -1 );
1315                 }
1316
1317                 if ( empty( $_POST['widget-id'] ) ) {
1318                         wp_send_json_error( 'missing_widget-id' );
1319                 }
1320
1321                 /** This action is documented in wp-admin/includes/ajax-actions.php */
1322                 do_action( 'load-widgets.php' );
1323
1324                 /** This action is documented in wp-admin/includes/ajax-actions.php */
1325                 do_action( 'widgets.php' );
1326
1327                 /** This action is documented in wp-admin/widgets.php */
1328                 do_action( 'sidebar_admin_setup' );
1329
1330                 $widget_id = $this->get_post_value( 'widget-id' );
1331                 $parsed_id = $this->parse_widget_id( $widget_id );
1332                 $id_base = $parsed_id['id_base'];
1333
1334                 $is_updating_widget_template = (
1335                         isset( $_POST[ 'widget-' . $id_base ] )
1336                         &&
1337                         is_array( $_POST[ 'widget-' . $id_base ] )
1338                         &&
1339                         preg_match( '/__i__|%i%/', key( $_POST[ 'widget-' . $id_base ] ) )
1340                 );
1341                 if ( $is_updating_widget_template ) {
1342                         wp_send_json_error( 'template_widget_not_updatable' );
1343                 }
1344
1345                 $updated_widget = $this->call_widget_update( $widget_id ); // => {instance,form}
1346                 if ( is_wp_error( $updated_widget ) ) {
1347                         wp_send_json_error( $updated_widget->get_error_message() );
1348                 }
1349
1350                 $form = $updated_widget['form'];
1351                 $instance = $this->sanitize_widget_js_instance( $updated_widget['instance'] );
1352
1353                 wp_send_json_success( compact( 'form', 'instance' ) );
1354         }
1355
1356         /***************************************************************************
1357          * Option Update Capturing
1358          ***************************************************************************/
1359
1360         /**
1361          * List of captured widget option updates.
1362          *
1363          * @since 3.9.0
1364          * @access protected
1365          * @var array $_captured_options Values updated while option capture is happening.
1366          */
1367         protected $_captured_options = array();
1368
1369         /**
1370          * Whether option capture is currently happening.
1371          *
1372          * @since 3.9.0
1373          * @access protected
1374          * @var bool $_is_current Whether option capture is currently happening or not.
1375          */
1376         protected $_is_capturing_option_updates = false;
1377
1378         /**
1379          * Determine whether the captured option update should be ignored.
1380          *
1381          * @since 3.9.0
1382          * @access protected
1383          *
1384          * @param string $option_name Option name.
1385          * @return boolean Whether the option capture is ignored.
1386          */
1387         protected function is_option_capture_ignored( $option_name ) {
1388                 return ( 0 === strpos( $option_name, '_transient_' ) );
1389         }
1390
1391         /**
1392          * Retrieve captured widget option updates.
1393          *
1394          * @since 3.9.0
1395          * @access protected
1396          *
1397          * @return array Array of captured options.
1398          */
1399         protected function get_captured_options() {
1400                 return $this->_captured_options;
1401         }
1402
1403         /**
1404          * Get the option that was captured from being saved.
1405          *
1406          * @since 4.2.0
1407          * @access protected
1408          *
1409          * @param string $option_name Option name.
1410          * @param mixed  $default     Optional. Default value to return if the option does not exist.
1411          * @return mixed Value set for the option.
1412          */
1413         protected function get_captured_option( $option_name, $default = false ) {
1414                 if ( array_key_exists( $option_name, $this->_captured_options ) ) {
1415                         $value = $this->_captured_options[ $option_name ];
1416                 } else {
1417                         $value = $default;
1418                 }
1419                 return $value;
1420         }
1421
1422         /**
1423          * Get the number of captured widget option updates.
1424          *
1425          * @since 3.9.0
1426          * @access protected
1427          *
1428          * @return int Number of updated options.
1429          */
1430         protected function count_captured_options() {
1431                 return count( $this->_captured_options );
1432         }
1433
1434         /**
1435          * Start keeping track of changes to widget options, caching new values.
1436          *
1437          * @since 3.9.0
1438          * @access protected
1439          */
1440         protected function start_capturing_option_updates() {
1441                 if ( $this->_is_capturing_option_updates ) {
1442                         return;
1443                 }
1444
1445                 $this->_is_capturing_option_updates = true;
1446
1447                 add_filter( 'pre_update_option', array( $this, 'capture_filter_pre_update_option' ), 10, 3 );
1448         }
1449
1450         /**
1451          * Pre-filter captured option values before updating.
1452          *
1453          * @since 3.9.0
1454          * @access public
1455          *
1456          * @param mixed  $new_value   The new option value.
1457          * @param string $option_name Name of the option.
1458          * @param mixed  $old_value   The old option value.
1459          * @return mixed Filtered option value.
1460          */
1461         public function capture_filter_pre_update_option( $new_value, $option_name, $old_value ) {
1462                 if ( $this->is_option_capture_ignored( $option_name ) ) {
1463                         return;
1464                 }
1465
1466                 if ( ! isset( $this->_captured_options[ $option_name ] ) ) {
1467                         add_filter( "pre_option_{$option_name}", array( $this, 'capture_filter_pre_get_option' ) );
1468                 }
1469
1470                 $this->_captured_options[ $option_name ] = $new_value;
1471
1472                 return $old_value;
1473         }
1474
1475         /**
1476          * Pre-filter captured option values before retrieving.
1477          *
1478          * @since 3.9.0
1479          * @access public
1480          *
1481          * @param mixed $value Value to return instead of the option value.
1482          * @return mixed Filtered option value.
1483          */
1484         public function capture_filter_pre_get_option( $value ) {
1485                 $option_name = preg_replace( '/^pre_option_/', '', current_filter() );
1486
1487                 if ( isset( $this->_captured_options[ $option_name ] ) ) {
1488                         $value = $this->_captured_options[ $option_name ];
1489
1490                         /** This filter is documented in wp-includes/option.php */
1491                         $value = apply_filters( 'option_' . $option_name, $value );
1492                 }
1493
1494                 return $value;
1495         }
1496
1497         /**
1498          * Undo any changes to the options since options capture began.
1499          *
1500          * @since 3.9.0
1501          * @access protected
1502          */
1503         protected function stop_capturing_option_updates() {
1504                 if ( ! $this->_is_capturing_option_updates ) {
1505                         return;
1506                 }
1507
1508                 remove_filter( 'pre_update_option', array( $this, 'capture_filter_pre_update_option' ), 10, 3 );
1509
1510                 foreach ( array_keys( $this->_captured_options ) as $option_name ) {
1511                         remove_filter( "pre_option_{$option_name}", array( $this, 'capture_filter_pre_get_option' ) );
1512                 }
1513
1514                 $this->_captured_options = array();
1515                 $this->_is_capturing_option_updates = false;
1516         }
1517
1518         /**
1519          * @since 3.9.0
1520          * @deprecated 4.2.0 Deprecated in favor of customize_dynamic_setting_args filter.
1521          */
1522         public function setup_widget_addition_previews() {
1523                 _deprecated_function( __METHOD__, '4.2.0' );
1524         }
1525
1526         /**
1527          * @since 3.9.0
1528          * @deprecated 4.2.0 Deprecated in favor of customize_dynamic_setting_args filter.
1529          */
1530         public function prepreview_added_sidebars_widgets() {
1531                 _deprecated_function( __METHOD__, '4.2.0' );
1532         }
1533
1534         /**
1535          * @since 3.9.0
1536          * @deprecated 4.2.0 Deprecated in favor of customize_dynamic_setting_args filter.
1537          */
1538         public function prepreview_added_widget_instance() {
1539                 _deprecated_function( __METHOD__, '4.2.0' );
1540         }
1541
1542         /**
1543          * @since 3.9.0
1544          * @deprecated 4.2.0 Deprecated in favor of customize_dynamic_setting_args filter.
1545          */
1546         public function remove_prepreview_filters() {
1547                 _deprecated_function( __METHOD__, '4.2.0' );
1548         }
1549 }