]> scripts.mit.edu Git - autoinstalls/wordpress.git/blobdiff - wp-includes/class-wp-customize-manager.php
WordPress 4.3
[autoinstalls/wordpress.git] / wp-includes / class-wp-customize-manager.php
index c14d61652ab28e114cb7b66d8e57b1e6f0d4125d..9cac338591189dc687fab0b940466d838c4f36bd 100644 (file)
@@ -1,6 +1,14 @@
 <?php
 /**
- * Customize Manager.
+ * WordPress Customize Manager classes
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 3.4.0
+ */
+
+/**
+ * Customize Manager class.
  *
  * Bootstraps the Customize experience on the server-side.
  *
@@ -10,8 +18,6 @@
  * Serves as a factory for Customize Controls and Settings, and
  * instantiates default Customize Controls and Settings.
  *
- * @package WordPress
- * @subpackage Customize
  * @since 3.4.0
  */
 final class WP_Customize_Manager {
@@ -32,7 +38,7 @@ final class WP_Customize_Manager {
        /**
         * Whether this is a Customizer pageload.
         *
-        * @var boolean
+        * @var bool
         */
        protected $previewing = false;
 
@@ -43,6 +49,13 @@ final class WP_Customize_Manager {
         */
        public $widgets;
 
+       /**
+        * Methods and properties deailing with managing nav menus in the Customizer.
+        *
+        * @var WP_Customize_Nav_Menus
+        */
+       public $nav_menus;
+
        protected $settings   = array();
        protected $containers = array();
        protected $panels     = array();
@@ -54,7 +67,25 @@ final class WP_Customize_Manager {
        protected $customized;
 
        /**
-        * Controls that may be rendered from JS templates.
+        * Panel types that may be rendered from JS templates.
+        *
+        * @since 4.3.0
+        * @access protected
+        * @var array
+        */
+       protected $registered_panel_types = array();
+
+       /**
+        * Section types that may be rendered from JS templates.
+        *
+        * @since 4.3.0
+        * @access protected
+        * @var array
+        */
+       protected $registered_section_types = array();
+
+       /**
+        * Control types that may be rendered from JS templates.
         *
         * @since 4.1.0
         * @access protected
@@ -65,7 +96,7 @@ final class WP_Customize_Manager {
        /**
         * Unsanitized values for Customize Settings parsed from $_POST['customized'].
         *
-        * @var array|false
+        * @var array
         */
        private $_post_values;
 
@@ -80,13 +111,15 @@ final class WP_Customize_Manager {
                require_once( ABSPATH . WPINC . '/class-wp-customize-section.php' );
                require_once( ABSPATH . WPINC . '/class-wp-customize-control.php' );
                require_once( ABSPATH . WPINC . '/class-wp-customize-widgets.php' );
+               require_once( ABSPATH . WPINC . '/class-wp-customize-nav-menus.php' );
 
                $this->widgets = new WP_Customize_Widgets( $this );
+               $this->nav_menus = new WP_Customize_Nav_Menus( $this );
 
                add_filter( 'wp_die_handler', array( $this, 'wp_die_handler' ) );
 
-               add_action( 'setup_theme',  array( $this, 'setup_theme' ) );
-               add_action( 'wp_loaded',    array( $this, 'wp_loaded' ) );
+               add_action( 'setup_theme', array( $this, 'setup_theme' ) );
+               add_action( 'wp_loaded',   array( $this, 'wp_loaded' ) );
 
                // Run wp_redirect_status late to make sure we override the status last.
                add_action( 'wp_redirect_status', array( $this, 'wp_redirect_status' ), 1000 );
@@ -99,9 +132,11 @@ final class WP_Customize_Manager {
                remove_action( 'admin_init', '_maybe_update_plugins' );
                remove_action( 'admin_init', '_maybe_update_themes' );
 
-               add_action( 'wp_ajax_customize_save', array( $this, 'save' ) );
+               add_action( 'wp_ajax_customize_save',           array( $this, 'save' ) );
+               add_action( 'wp_ajax_customize_refresh_nonces', array( $this, 'refresh_nonces' ) );
 
                add_action( 'customize_register',                 array( $this, 'register_controls' ) );
+               add_action( 'customize_register',                 array( $this, 'register_dynamic_settings' ), 11 ); // allow code to create settings first
                add_action( 'customize_controls_init',            array( $this, 'prepare_controls' ) );
                add_action( 'customize_controls_enqueue_scripts', array( $this, 'enqueue_control_scripts' ) );
        }
@@ -110,11 +145,27 @@ final class WP_Customize_Manager {
         * Return true if it's an AJAX request.
         *
         * @since 3.4.0
+        * @since 4.2.0 Added `$action` param.
+        * @access public
         *
-        * @return bool
+        * @param string|null $action Whether the supplied AJAX action is being run.
+        * @return bool True if it's an AJAX request, false otherwise.
         */
-       public function doing_ajax() {
-               return isset( $_POST['customized'] ) || ( defined( 'DOING_AJAX' ) && DOING_AJAX );
+       public function doing_ajax( $action = null ) {
+               $doing_ajax = ( defined( 'DOING_AJAX' ) && DOING_AJAX );
+               if ( ! $doing_ajax ) {
+                       return false;
+               }
+
+               if ( ! $action ) {
+                       return true;
+               } else {
+                       /*
+                        * Note: we can't just use doing_action( "wp_ajax_{$action}" ) because we need
+                        * to check before admin-ajax.php gets to that point.
+                        */
+                       return isset( $_REQUEST['action'] ) && wp_unslash( $_REQUEST['action'] ) === $action;
+               }
        }
 
        /**
@@ -127,11 +178,13 @@ final class WP_Customize_Manager {
         * @param mixed $message UI message
         */
        protected function wp_die( $ajax_message, $message = null ) {
-               if ( $this->doing_ajax() )
+               if ( $this->doing_ajax() || isset( $_POST['customized'] ) ) {
                        wp_die( $ajax_message );
+               }
 
-               if ( ! $message )
+               if ( ! $message ) {
                        $message = __( 'Cheatin&#8217; uh?' );
+               }
 
                wp_die( $message );
        }
@@ -144,8 +197,9 @@ final class WP_Customize_Manager {
         * @return string
         */
        public function wp_die_handler() {
-               if ( $this->doing_ajax() )
+               if ( $this->doing_ajax() || isset( $_POST['customized'] ) ) {
                        return '_ajax_wp_die_handler';
+               }
 
                return '_default_wp_die_handler';
        }
@@ -160,10 +214,12 @@ final class WP_Customize_Manager {
        public function setup_theme() {
                send_origin_headers();
 
-               if ( is_admin() && ! $this->doing_ajax() )
-                   auth_redirect();
-               elseif ( $this->doing_ajax() && ! is_user_logged_in() )
-                   $this->wp_die( 0 );
+               $doing_ajax_or_is_customized = ( $this->doing_ajax() || isset( $_POST['customized'] ) );
+               if ( is_admin() && ! $doing_ajax_or_is_customized ) {
+                       auth_redirect();
+               } elseif ( $doing_ajax_or_is_customized && ! is_user_logged_in() ) {
+                       $this->wp_die( 0 );
+               }
 
                show_admin_bar( false );
 
@@ -181,16 +237,19 @@ final class WP_Customize_Manager {
                } else {
                        // If the requested theme is not the active theme and the user doesn't have the
                        // switch_themes cap, bail.
-                       if ( ! current_user_can( 'switch_themes' ) )
+                       if ( ! current_user_can( 'switch_themes' ) ) {
                                $this->wp_die( -1 );
+                       }
 
                        // If the theme has errors while loading, bail.
-                       if ( $this->theme()->errors() )
+                       if ( $this->theme()->errors() ) {
                                $this->wp_die( -1 );
+                       }
 
                        // If the theme isn't allowed per multisite settings, bail.
-                       if ( ! $this->theme()->is_allowed() )
+                       if ( ! $this->theme()->is_allowed() ) {
                                $this->wp_die( -1 );
+                       }
                }
 
                $this->start_previewing_theme();
@@ -202,7 +261,8 @@ final class WP_Customize_Manager {
         * @since 3.4.0
         */
        public function after_setup_theme() {
-               if ( ! $this->doing_ajax() && ! validate_current_theme() ) {
+               $doing_ajax_or_is_customized = ( $this->doing_ajax() || isset( $_SERVER['customized'] ) );
+               if ( ! $doing_ajax_or_is_customized && ! validate_current_theme() ) {
                        wp_redirect( 'themes.php?broken=true' );
                        exit;
                }
@@ -216,8 +276,9 @@ final class WP_Customize_Manager {
         */
        public function start_previewing_theme() {
                // Bail if we're already previewing.
-               if ( $this->is_preview() )
+               if ( $this->is_preview() ) {
                        return;
+               }
 
                $this->previewing = true;
 
@@ -253,8 +314,9 @@ final class WP_Customize_Manager {
         * @since 3.4.0
         */
        public function stop_previewing_theme() {
-               if ( ! $this->is_preview() )
+               if ( ! $this->is_preview() ) {
                        return;
+               }
 
                $this->previewing = false;
 
@@ -290,6 +352,9 @@ final class WP_Customize_Manager {
         * @return WP_Theme
         */
        public function theme() {
+               if ( ! $this->theme ) {
+                       $this->theme = wp_get_theme();
+               }
                return $this->theme;
        }
 
@@ -411,8 +476,8 @@ final class WP_Customize_Manager {
                        if ( isset( $_POST['customized'] ) ) {
                                $this->_post_values = json_decode( wp_unslash( $_POST['customized'] ), true );
                        }
-                       if ( empty( $this->_post_values ) ) { // if not isset or of JSON error
-                               $this->_post_values = false;
+                       if ( empty( $this->_post_values ) ) { // if not isset or if JSON error
+                               $this->_post_values = array();
                        }
                }
                if ( empty( $this->_post_values ) ) {
@@ -441,6 +506,20 @@ final class WP_Customize_Manager {
                }
        }
 
+       /**
+        * Override a setting's (unsanitized) value as found in any incoming $_POST['customized'].
+        *
+        * @since 4.2.0
+        * @access public
+        *
+        * @param string $setting_id ID for the WP_Customize_Setting instance.
+        * @param mixed  $value      Post value.
+        */
+       public function set_post_value( $setting_id, $value ) {
+               $this->unsanitized_post_values();
+               $this->_post_values[ $setting_id ] = $value;
+       }
+
        /**
         * Print JavaScript settings.
         *
@@ -455,6 +534,7 @@ final class WP_Customize_Manager {
                add_action( 'wp', array( $this, 'customize_preview_override_404_status' ) );
                add_action( 'wp_head', array( $this, 'customize_preview_base' ) );
                add_action( 'wp_head', array( $this, 'customize_preview_html5' ) );
+               add_action( 'wp_head', array( $this, 'customize_preview_loading_style' ) );
                add_action( 'wp_footer', array( $this, 'customize_preview_settings' ), 20 );
                add_action( 'shutdown', array( $this, 'customize_preview_signature' ), 1000 );
                add_filter( 'wp_die_handler', array( $this, 'remove_preview_signature' ) );
@@ -497,7 +577,7 @@ final class WP_Customize_Manager {
        }
 
        /**
-        * Print a workaround to handle HTML5 tags in IE < 9
+        * Print a workaround to handle HTML5 tags in IE < 9.
         *
         * @since 3.4.0
         */
@@ -514,6 +594,26 @@ final class WP_Customize_Manager {
                <![endif]--><?php
        }
 
+       /**
+        * Print CSS for loading indicators for the Customizer preview.
+        *
+        * @since 4.2.0
+        * @access public
+        */
+       public function customize_preview_loading_style() {
+               ?><style>
+                       body.wp-customizer-unloading {
+                               opacity: 0.25;
+                               cursor: progress !important;
+                               -webkit-transition: opacity 0.5s;
+                               transition: opacity 0.5s;
+                       }
+                       body.wp-customizer-unloading * {
+                               pointer-events: none !important;
+                       }
+               </style><?php
+       }
+
        /**
         * Print JavaScript settings for preview frame.
         *
@@ -526,6 +626,9 @@ final class WP_Customize_Manager {
                        'activePanels' => array(),
                        'activeSections' => array(),
                        'activeControls' => array(),
+                       'l10n' => array(
+                               'loading'  => __( 'Loading ...' ),
+                       ),
                );
 
                if ( 2 == $this->nonce_tick ) {
@@ -536,19 +639,29 @@ final class WP_Customize_Manager {
                }
 
                foreach ( $this->settings as $id => $setting ) {
-                       $settings['values'][ $id ] = $setting->js_value();
+                       if ( $setting->check_capabilities() ) {
+                               $settings['values'][ $id ] = $setting->js_value();
+                       }
                }
-               foreach ( $this->panels as $id => $panel ) {
-                       $settings['activePanels'][ $id ] = $panel->active();
-                       foreach ( $panel->sections as $id => $section ) {
-                               $settings['activeSections'][ $id ] = $section->active();
+               foreach ( $this->panels as $panel_id => $panel ) {
+                       if ( $panel->check_capabilities() ) {
+                               $settings['activePanels'][ $panel_id ] = $panel->active();
+                               foreach ( $panel->sections as $section_id => $section ) {
+                                       if ( $section->check_capabilities() ) {
+                                               $settings['activeSections'][ $section_id ] = $section->active();
+                                       }
+                               }
                        }
                }
                foreach ( $this->sections as $id => $section ) {
-                       $settings['activeSections'][ $id ] = $section->active();
+                       if ( $section->check_capabilities() ) {
+                               $settings['activeSections'][ $id ] = $section->active();
+                       }
                }
                foreach ( $this->controls as $id => $control ) {
-                       $settings['activeControls'][ $id ] = $control->active();
+                       if ( $control->check_capabilities() ) {
+                               $settings['activeControls'][ $id ] = $control->active();
+                       }
                }
 
                ?>
@@ -571,6 +684,8 @@ final class WP_Customize_Manager {
         * Removes the signature in case we experience a case where the Customizer was not properly executed.
         *
         * @since 3.4.0
+        *
+        * @return mixed
         */
        public function remove_preview_signature( $return = null ) {
                remove_action( 'shutdown', array( $this, 'customize_preview_signature' ), 1000 );
@@ -651,10 +766,14 @@ final class WP_Customize_Manager {
         * @since 3.4.0
         */
        public function save() {
-               if ( ! $this->is_preview() )
-                       die;
+               if ( ! $this->is_preview() ) {
+                       wp_send_json_error( 'not_preview' );
+               }
 
-               check_ajax_referer( 'save-customize_' . $this->get_stylesheet(), 'nonce' );
+               $action = 'save-customize_' . $this->get_stylesheet();
+               if ( ! check_ajax_referer( $action, 'nonce', false ) ) {
+                       wp_send_json_error( 'invalid_nonce' );
+               }
 
                // Do we have to switch themes?
                if ( ! $this->is_theme_active() ) {
@@ -689,7 +808,47 @@ final class WP_Customize_Manager {
                 */
                do_action( 'customize_save_after', $this );
 
-               die;
+               /**
+                * Filter response data for a successful customize_save AJAX request.
+                *
+                * This filter does not apply if there was a nonce or authentication failure.
+                *
+                * @since 4.2.0
+                *
+                * @param array                $data Additional information passed back to the 'saved'
+                *                                   event on `wp.customize`.
+                * @param WP_Customize_Manager $this WP_Customize_Manager instance.
+                */
+               $response = apply_filters( 'customize_save_response', array(), $this );
+               wp_send_json_success( $response );
+       }
+
+       /**
+        * Refresh nonces for the current preview.
+        *
+        * @since 4.2.0
+        */
+       public function refresh_nonces() {
+               if ( ! $this->is_preview() ) {
+                       wp_send_json_error( 'not_preview' );
+               }
+
+               $nonces = array(
+                       'save'    => wp_create_nonce( 'save-customize_' . $this->get_stylesheet() ),
+                       'preview' => wp_create_nonce( 'preview-customize_' . $this->get_stylesheet() ),
+               );
+
+               /**
+                * Filter nonces for a customize_refresh_nonces AJAX request.
+                *
+                * @since 4.2.0
+                *
+                * @param array                $nonces Array of refreshed nonces for save and
+                *                                     preview actions.
+                * @param WP_Customize_Manager $this   WP_Customize_Manager instance.
+                */
+               $nonces = apply_filters( 'customize_refresh_nonces', $nonces, $this );
+               wp_send_json_success( $nonces );
        }
 
        /**
@@ -702,25 +861,87 @@ final class WP_Customize_Manager {
         *                                        constructor.
         */
        public function add_setting( $id, $args = array() ) {
-               if ( is_a( $id, 'WP_Customize_Setting' ) )
+               if ( $id instanceof WP_Customize_Setting ) {
                        $setting = $id;
-               else
+               } else {
                        $setting = new WP_Customize_Setting( $this, $id, $args );
-
+               }
                $this->settings[ $setting->id ] = $setting;
        }
 
+       /**
+        * Register any dynamically-created settings, such as those from $_POST['customized']
+        * that have no corresponding setting created.
+        *
+        * This is a mechanism to "wake up" settings that have been dynamically created
+        * on the frontend and have been sent to WordPress in `$_POST['customized']`. When WP
+        * loads, the dynamically-created settings then will get created and previewed
+        * even though they are not directly created statically with code.
+        *
+        * @since 4.2.0
+        *
+        * @param array $setting_ids The setting IDs to add.
+        * @return WP_Customize_Setting The settings added.
+        */
+       public function add_dynamic_settings( $setting_ids ) {
+               $new_settings = array();
+               foreach ( $setting_ids as $setting_id ) {
+                       // Skip settings already created
+                       if ( $this->get_setting( $setting_id ) ) {
+                               continue;
+                       }
+
+                       $setting_args = false;
+                       $setting_class = 'WP_Customize_Setting';
+
+                       /**
+                        * Filter a dynamic setting's constructor args.
+                        *
+                        * For a dynamic setting to be registered, this filter must be employed
+                        * to override the default false value with an array of args to pass to
+                        * the WP_Customize_Setting constructor.
+                        *
+                        * @since 4.2.0
+                        *
+                        * @param false|array $setting_args The arguments to the WP_Customize_Setting constructor.
+                        * @param string      $setting_id   ID for dynamic setting, usually coming from `$_POST['customized']`.
+                        */
+                       $setting_args = apply_filters( 'customize_dynamic_setting_args', $setting_args, $setting_id );
+                       if ( false === $setting_args ) {
+                               continue;
+                       }
+
+                       /**
+                        * Allow non-statically created settings to be constructed with custom WP_Customize_Setting subclass.
+                        *
+                        * @since 4.2.0
+                        *
+                        * @param string $setting_class WP_Customize_Setting or a subclass.
+                        * @param string $setting_id    ID for dynamic setting, usually coming from `$_POST['customized']`.
+                        * @param array  $setting_args  WP_Customize_Setting or a subclass.
+                        */
+                       $setting_class = apply_filters( 'customize_dynamic_setting_class', $setting_class, $setting_id, $setting_args );
+
+                       $setting = new $setting_class( $this, $setting_id, $setting_args );
+
+                       $this->add_setting( $setting );
+                       $new_settings[] = $setting;
+               }
+               return $new_settings;
+       }
+
        /**
         * Retrieve a customize setting.
         *
         * @since 3.4.0
         *
         * @param string $id Customize Setting ID.
-        * @return WP_Customize_Setting
+        * @return WP_Customize_Setting|void The setting, if set.
         */
        public function get_setting( $id ) {
-               if ( isset( $this->settings[ $id ] ) )
+               if ( isset( $this->settings[ $id ] ) ) {
                        return $this->settings[ $id ];
+               }
        }
 
        /**
@@ -744,10 +965,9 @@ final class WP_Customize_Manager {
         * @param array                     $args Optional. Panel arguments. Default empty array.
         */
        public function add_panel( $id, $args = array() ) {
-               if ( is_a( $id, 'WP_Customize_Panel' ) ) {
+               if ( $id instanceof WP_Customize_Panel ) {
                        $panel = $id;
-               }
-               else {
+               } else {
                        $panel = new WP_Customize_Panel( $this, $id, $args );
                }
 
@@ -761,7 +981,7 @@ final class WP_Customize_Manager {
         * @access public
         *
         * @param string $id Panel ID to get.
-        * @return WP_Customize_Panel Requested panel instance.
+        * @return WP_Customize_Panel|void Requested panel instance, if set.
         */
        public function get_panel( $id ) {
                if ( isset( $this->panels[ $id ] ) ) {
@@ -781,6 +1001,35 @@ final class WP_Customize_Manager {
                unset( $this->panels[ $id ] );
        }
 
+       /**
+        * Register a customize panel type.
+        *
+        * Registered types are eligible to be rendered via JS and created dynamically.
+        *
+        * @since 4.3.0
+        * @access public
+        *
+        * @see WP_Customize_Panel
+        *
+        * @param string $panel Name of a custom panel which is a subclass of WP_Customize_Panel.
+        */
+       public function register_panel_type( $panel ) {
+               $this->registered_panel_types[] = $panel;
+       }
+
+       /**
+        * Render JS templates for all registered panel types.
+        *
+        * @since 4.3.0
+        * @access public
+        */
+       public function render_panel_templates() {
+               foreach ( $this->registered_panel_types as $panel_type ) {
+                       $panel = new $panel_type( $this, 'temp', array() );
+                       $panel->print_template();
+               }
+       }
+
        /**
         * Add a customize section.
         *
@@ -790,11 +1039,11 @@ final class WP_Customize_Manager {
         * @param array                       $args Section arguments.
         */
        public function add_section( $id, $args = array() ) {
-               if ( is_a( $id, 'WP_Customize_Section' ) )
+               if ( $id instanceof WP_Customize_Section ) {
                        $section = $id;
-               else
+               } else {
                        $section = new WP_Customize_Section( $this, $id, $args );
-
+               }
                $this->sections[ $section->id ] = $section;
        }
 
@@ -804,7 +1053,7 @@ final class WP_Customize_Manager {
         * @since 3.4.0
         *
         * @param string $id Section ID.
-        * @return WP_Customize_Section
+        * @return WP_Customize_Section|void The section, if set.
         */
        public function get_section( $id ) {
                if ( isset( $this->sections[ $id ] ) )
@@ -822,6 +1071,35 @@ final class WP_Customize_Manager {
                unset( $this->sections[ $id ] );
        }
 
+       /**
+        * Register a customize section type.
+        *
+        * Registered types are eligible to be rendered via JS and created dynamically.
+        *
+        * @since 4.3.0
+        * @access public
+        *
+        * @see WP_Customize_Section
+        *
+        * @param string $section Name of a custom section which is a subclass of WP_Customize_Section.
+        */
+       public function register_section_type( $section ) {
+               $this->registered_section_types[] = $section;
+       }
+
+       /**
+        * Render JS templates for all registered section types.
+        *
+        * @since 4.3.0
+        * @access public
+        */
+       public function render_section_templates() {
+               foreach ( $this->registered_section_types as $section_type ) {
+                       $section = new $section_type( $this, 'temp', array() );
+                       $section->print_template();
+               }
+       }
+
        /**
         * Add a customize control.
         *
@@ -832,11 +1110,11 @@ final class WP_Customize_Manager {
         *                                          constructor.
         */
        public function add_control( $id, $args = array() ) {
-               if ( is_a( $id, 'WP_Customize_Control' ) )
+               if ( $id instanceof WP_Customize_Control ) {
                        $control = $id;
-               else
+               } else {
                        $control = new WP_Customize_Control( $this, $id, $args );
-
+               }
                $this->controls[ $control->id ] = $control;
        }
 
@@ -846,7 +1124,7 @@ final class WP_Customize_Manager {
         * @since 3.4.0
         *
         * @param string $id ID of the control.
-        * @return WP_Customize_Control $control The control object.
+        * @return WP_Customize_Control|void The control object, if set.
         */
        public function get_control( $id ) {
                if ( isset( $this->controls[ $id ] ) )
@@ -897,11 +1175,11 @@ final class WP_Customize_Manager {
         *
         * @since 3.4.0
         *
-        * @param {WP_Customize_Panel|WP_Customize_Section|WP_Customize_Control} $a Object A.
-        * @param {WP_Customize_Panel|WP_Customize_Section|WP_Customize_Control} $b Object B.
+        * @param WP_Customize_Panel|WP_Customize_Section|WP_Customize_Control $a Object A.
+        * @param WP_Customize_Panel|WP_Customize_Section|WP_Customize_Control $b Object B.
         * @return int
         */
-       protected final function _cmp_priority( $a, $b ) {
+       protected function _cmp_priority( $a, $b ) {
                if ( $a->priority === $b->priority ) {
                        return $a->instance_number - $a->instance_number;
                } else {
@@ -938,7 +1216,7 @@ final class WP_Customize_Manager {
                $sections = array();
 
                foreach ( $this->sections as $section ) {
-                       if ( ! $section->check_capabilities() || ! $section->controls ) {
+                       if ( ! $section->check_capabilities() ) {
                                continue;
                        }
 
@@ -961,7 +1239,7 @@ final class WP_Customize_Manager {
                $panels = array();
 
                foreach ( $this->panels as $panel ) {
-                       if ( ! $panel->check_capabilities() || ! $panel->sections ) {
+                       if ( ! $panel->check_capabilities() ) {
                                continue;
                        }
 
@@ -993,16 +1271,67 @@ final class WP_Customize_Manager {
         */
        public function register_controls() {
 
-               /* Control Types (custom control classes) */
+               /* Panel, Section, and Control Types */
+               $this->register_panel_type( 'WP_Customize_Panel' );
+               $this->register_section_type( 'WP_Customize_Section' );
+               $this->register_section_type( 'WP_Customize_Sidebar_Section' );
                $this->register_control_type( 'WP_Customize_Color_Control' );
+               $this->register_control_type( 'WP_Customize_Media_Control' );
                $this->register_control_type( 'WP_Customize_Upload_Control' );
                $this->register_control_type( 'WP_Customize_Image_Control' );
                $this->register_control_type( 'WP_Customize_Background_Image_Control' );
+               $this->register_control_type( 'WP_Customize_Cropped_Image_Control' );
+               $this->register_control_type( 'WP_Customize_Site_Icon_Control' );
+               $this->register_control_type( 'WP_Customize_Theme_Control' );
+
+               /* Themes */
 
-               /* Site Title & Tagline */
+               $this->add_section( new WP_Customize_Themes_Section( $this, 'themes', array(
+                       'title'      => $this->theme()->display( 'Name' ),
+                       'capability' => 'switch_themes',
+                       'priority'   => 0,
+               ) ) );
+
+               // Themes Setting (unused - the theme is considerably more fundamental to the Customizer experience).
+               $this->add_setting( new WP_Customize_Filter_Setting( $this, 'active_theme', array(
+                       'capability' => 'switch_themes',
+               ) ) );
+
+               require_once( ABSPATH . 'wp-admin/includes/theme.php' );
+
+               // Theme Controls.
+
+               // Add a control for the active/original theme.
+               if ( ! $this->is_theme_active() ) {
+                       $themes = wp_prepare_themes_for_js( array( wp_get_theme( $this->original_stylesheet ) ) );
+                       $active_theme = current( $themes );
+                       $active_theme['isActiveTheme'] = true;
+                       $this->add_control( new WP_Customize_Theme_Control( $this, $active_theme['id'], array(
+                               'theme'    => $active_theme,
+                               'section'  => 'themes',
+                               'settings' => 'active_theme',
+                       ) ) );
+               }
+
+               $themes = wp_prepare_themes_for_js();
+               foreach ( $themes as $theme ) {
+                       if ( $theme['active'] || $theme['id'] === $this->original_stylesheet ) {
+                               continue;
+                       }
+
+                       $theme_id = 'theme_' . $theme['id'];
+                       $theme['isActiveTheme'] = false;
+                       $this->add_control( new WP_Customize_Theme_Control( $this, $theme_id, array(
+                               'theme'    => $theme,
+                               'section'  => 'themes',
+                               'settings' => 'active_theme',
+                       ) ) );
+               }
+
+               /* Site Identity */
 
                $this->add_section( 'title_tagline', array(
-                       'title'    => __( 'Site Title & Tagline' ),
+                       'title'    => __( 'Site Identity' ),
                        'priority' => 20,
                ) );
 
@@ -1028,6 +1357,21 @@ final class WP_Customize_Manager {
                        'section'    => 'title_tagline',
                ) );
 
+               $this->add_setting( 'site_icon', array(
+                       'type'       => 'option',
+                       'capability' => 'manage_options',
+                       'transport'  => 'postMessage', // Previewed with JS in the Customizer controls window.
+               ) );
+
+               $this->add_control( new WP_Customize_Site_Icon_Control( $this, 'site_icon', array(
+                       'label'       => __( 'Site Icon' ),
+                       'description' => __( 'The Site Icon is used as a browser and app icon for your site. Icons must be square, and at least 512px wide and tall.' ),
+                       'section'     => 'title_tagline',
+                       'priority'    => 60,
+                       'height'      => 512,
+                       'width'       => 512,
+               ) ) );
+
                /* Colors */
 
                $this->add_section( 'colors', array(
@@ -1050,6 +1394,7 @@ final class WP_Customize_Manager {
                        'label'    => __( 'Display Header Text' ),
                        'section'  => 'title_tagline',
                        'type'     => 'checkbox',
+                       'priority' => 40,
                ) );
 
                $this->add_control( new WP_Customize_Color_Control( $this, 'header_textcolor', array(
@@ -1168,92 +1513,71 @@ final class WP_Customize_Manager {
                        }
                }
 
-               /* Nav Menus */
-
-               $locations      = get_registered_nav_menus();
-               $menus          = wp_get_nav_menus();
-               $num_locations  = count( array_keys( $locations ) );
-
-               $this->add_section( 'nav', array(
-                       'title'          => __( 'Navigation' ),
-                       'theme_supports' => 'menus',
-                       'priority'       => 100,
-                       'description'    => sprintf( _n('Your theme supports %s menu. Select which menu you would like to use.', 'Your theme supports %s menus. Select which menu appears in each location.', $num_locations ), number_format_i18n( $num_locations ) ) . "\n\n" . __('You can edit your menu content on the Menus screen in the Appearance section.'),
-               ) );
-
-               if ( $menus ) {
-                       $choices = array( 0 => __( '&mdash; Select &mdash;' ) );
-                       foreach ( $menus as $menu ) {
-                               $choices[ $menu->term_id ] = wp_html_excerpt( $menu->name, 40, '&hellip;' );
-                       }
-
-                       foreach ( $locations as $location => $description ) {
-                               $menu_setting_id = "nav_menu_locations[{$location}]";
-
-                               $this->add_setting( $menu_setting_id, array(
-                                       'sanitize_callback' => 'absint',
-                                       'theme_supports'    => 'menus',
-                               ) );
-
-                               $this->add_control( $menu_setting_id, array(
-                                       'label'   => $description,
-                                       'section' => 'nav',
-                                       'type'    => 'select',
-                                       'choices' => $choices,
-                               ) );
-                       }
-               }
-
                /* Static Front Page */
                // #WP19627
 
-               $this->add_section( 'static_front_page', array(
-                       'title'          => __( 'Static Front Page' ),
-               //      'theme_supports' => 'static-front-page',
-                       'priority'       => 120,
-                       'description'    => __( 'Your theme supports a static front page.' ),
-               ) );
-
-               $this->add_setting( 'show_on_front', array(
-                       'default'        => get_option( 'show_on_front' ),
-                       'capability'     => 'manage_options',
-                       'type'           => 'option',
-               //      'theme_supports' => 'static-front-page',
-               ) );
-
-               $this->add_control( 'show_on_front', array(
-                       'label'   => __( 'Front page displays' ),
-                       'section' => 'static_front_page',
-                       'type'    => 'radio',
-                       'choices' => array(
-                               'posts' => __( 'Your latest posts' ),
-                               'page'  => __( 'A static page' ),
-                       ),
-               ) );
-
-               $this->add_setting( 'page_on_front', array(
-                       'type'       => 'option',
-                       'capability' => 'manage_options',
-               //      'theme_supports' => 'static-front-page',
-               ) );
-
-               $this->add_control( 'page_on_front', array(
-                       'label'      => __( 'Front page' ),
-                       'section'    => 'static_front_page',
-                       'type'       => 'dropdown-pages',
-               ) );
-
-               $this->add_setting( 'page_for_posts', array(
-                       'type'           => 'option',
-                       'capability'     => 'manage_options',
-               //      'theme_supports' => 'static-front-page',
-               ) );
+               // Replicate behavior from options-reading.php and hide front page options if there are no pages
+               if ( get_pages() ) {
+                       $this->add_section( 'static_front_page', array(
+                               'title'          => __( 'Static Front Page' ),
+                       //      'theme_supports' => 'static-front-page',
+                               'priority'       => 120,
+                               'description'    => __( 'Your theme supports a static front page.' ),
+                       ) );
+
+                       $this->add_setting( 'show_on_front', array(
+                               'default'        => get_option( 'show_on_front' ),
+                               'capability'     => 'manage_options',
+                               'type'           => 'option',
+                       //      'theme_supports' => 'static-front-page',
+                       ) );
+
+                       $this->add_control( 'show_on_front', array(
+                               'label'   => __( 'Front page displays' ),
+                               'section' => 'static_front_page',
+                               'type'    => 'radio',
+                               'choices' => array(
+                                       'posts' => __( 'Your latest posts' ),
+                                       'page'  => __( 'A static page' ),
+                               ),
+                       ) );
+
+                       $this->add_setting( 'page_on_front', array(
+                               'type'       => 'option',
+                               'capability' => 'manage_options',
+                       //      'theme_supports' => 'static-front-page',
+                       ) );
+
+                       $this->add_control( 'page_on_front', array(
+                               'label'      => __( 'Front page' ),
+                               'section'    => 'static_front_page',
+                               'type'       => 'dropdown-pages',
+                       ) );
+
+                       $this->add_setting( 'page_for_posts', array(
+                               'type'           => 'option',
+                               'capability'     => 'manage_options',
+                       //      'theme_supports' => 'static-front-page',
+                       ) );
+
+                       $this->add_control( 'page_for_posts', array(
+                               'label'      => __( 'Posts page' ),
+                               'section'    => 'static_front_page',
+                               'type'       => 'dropdown-pages',
+                       ) );
+               }
+       }
 
-               $this->add_control( 'page_for_posts', array(
-                       'label'      => __( 'Posts page' ),
-                       'section'    => 'static_front_page',
-                       'type'       => 'dropdown-pages',
-               ) );
+       /**
+        * Add settings from the POST data that were not added with code, e.g. dynamically-created settings for Widgets
+        *
+        * @since 4.2.0
+        * @access public
+        *
+        * @see add_dynamic_settings()
+        */
+       public function register_dynamic_settings() {
+               $this->add_dynamic_settings( array_keys( $this->unsanitized_post_values() ) );
        }
 
        /**
@@ -1265,7 +1589,7 @@ final class WP_Customize_Manager {
         * @since 3.4.0
         *
         * @param string $color
-        * @return string
+        * @return mixed
         */
        public function _sanitize_header_textcolor( $color ) {
                if ( 'blank' === $color )
@@ -1282,13 +1606,13 @@ final class WP_Customize_Manager {
 /**
  * Sanitizes a hex color.
  *
- * Returns either '', a 3 or 6 digit hex color (with #), or null.
+ * Returns either '', a 3 or 6 digit hex color (with #), or nothing.
  * For sanitizing values without a #, see sanitize_hex_color_no_hash().
  *
  * @since 3.4.0
  *
  * @param string $color
- * @return string|null
+ * @return string|void
  */
 function sanitize_hex_color( $color ) {
        if ( '' === $color )
@@ -1297,8 +1621,6 @@ function sanitize_hex_color( $color ) {
        // 3 or 6 hex digits, or the empty string.
        if ( preg_match('|^#([A-Fa-f0-9]{3}){1,2}$|', $color ) )
                return $color;
-
-       return null;
 }
 
 /**