wp-includes/js/customize-preview.js

   1 /*
   2  * Script run inside a Customizer preview frame.
   3  */
   4 (function( exports, $ ){
   5         var api = wp.customize,
   6                 debounce;
   7
   8         /**
   9          * Returns a debounced version of the function.
  10          *
  11          * @todo Require Underscore.js for this file and retire this.
  12          */
  13         debounce = function( fn, delay, context ) {
  14                 var timeout;
  15                 return function() {
  16                         var args = arguments;
  17
  18                         context = context || this;
  19
  20                         clearTimeout( timeout );
  21                         timeout = setTimeout( function() {
  22                                 timeout = null;
  23                                 fn.apply( context, args );
  24                         }, delay );
  25                 };
  26         };
  27
  28         /**
  29          * @constructor
  30          * @augments wp.customize.Messenger
  31          * @augments wp.customize.Class
  32          * @mixes wp.customize.Events
  33          */
  34         api.Preview = api.Messenger.extend({
  35                 /**
  36                  * @param {string} url The URL of preview frame
  37                  */
  38                 initialize: function( params, options ) {
  39                         var self = this;
  40
  41                         api.Messenger.prototype.initialize.call( this, params, options );
  42
  43                         this.body = $( document.body );
  44                         this.body.on( 'click.preview', 'a', function( event ) {
  45                                 event.preventDefault();
  46                                 self.send( 'scroll', 0 );
  47                                 self.send( 'url', $(this).prop('href') );
  48                         });
  49
  50                         // You cannot submit forms.
  51                         // @todo: Allow form submissions by mixing $_POST data with the customize setting $_POST data.
  52                         this.body.on( 'submit.preview', 'form', function( event ) {
  53                                 event.preventDefault();
  54                         });
  55
  56                         this.window = $( window );
  57                         this.window.on( 'scroll.preview', debounce( function() {
  58                                 self.send( 'scroll', self.window.scrollTop() );
  59                         }, 200 ));
  60
  61                         this.bind( 'scroll', function( distance ) {
  62                                 self.window.scrollTop( distance );
  63                         });
  64                 }
  65         });
  66
  67         $( function() {
  68                 api.settings = window._wpCustomizeSettings;
  69                 if ( ! api.settings )
  70                         return;
  71
  72                 var bg;
  73
  74                 api.preview = new api.Preview({
  75                         url: window.location.href,
  76                         channel: api.settings.channel
  77                 });
  78
  79                 api.preview.bind( 'settings', function( values ) {
  80                         $.each( values, function( id, value ) {
  81                                 if ( api.has( id ) )
  82                                         api( id ).set( value );
  83                                 else
  84                                         api.create( id, value );
  85                         });
  86                 });
  87
  88                 api.preview.trigger( 'settings', api.settings.values );
  89
  90                 api.preview.bind( 'setting', function( args ) {
  91                         var value;
  92
  93                         args = args.slice();
  94
  95                         if ( value = api( args.shift() ) )
  96                                 value.set.apply( value, args );
  97                 });
  98
  99                 api.preview.bind( 'sync', function( events ) {
 100                         $.each( events, function( event, args ) {
 101                                 api.preview.trigger( event, args );
 102                         });
 103                         api.preview.send( 'synced' );
 104                 });
 105
 106                 api.preview.bind( 'active', function() {
 107                         if ( api.settings.nonce ) {
 108                                 api.preview.send( 'nonce', api.settings.nonce );
 109                         }
 110
 111                         api.preview.send( 'documentTitle', document.title );
 112                 });
 113
 114                 /*
 115                  * Send a message to the parent customize frame with a list of which
 116                  * containers and controls are active.
 117                  */
 118                 api.preview.send( 'ready', {
 119                         activePanels: api.settings.activePanels,
 120                         activeSections: api.settings.activeSections,
 121                         activeControls: api.settings.activeControls
 122                 } );
 123
 124                 // Display a loading indicator when preview is reloading, and remove on failure.
 125                 api.preview.bind( 'loading-initiated', function () {
 126                         $( 'body' ).addClass( 'wp-customizer-unloading' );
 127                 });
 128                 api.preview.bind( 'loading-failed', function () {
 129                         $( 'body' ).removeClass( 'wp-customizer-unloading' );
 130                 });
 131
 132                 /* Custom Backgrounds */
 133                 bg = $.map(['color', 'image', 'position_x', 'repeat', 'attachment'], function( prop ) {
 134                         return 'background_' + prop;
 135                 });
 136
 137                 api.when.apply( api, bg ).done( function( color, image, position_x, repeat, attachment ) {
 138                         var body = $(document.body),
 139                                 head = $('head'),
 140                                 style = $('#custom-background-css'),
 141                                 update;
 142
 143                         update = function() {
 144                                 var css = '';
 145
 146                                 // The body will support custom backgrounds if either
 147                                 // the color or image are set.
 148                                 //
 149                                 // See get_body_class() in /wp-includes/post-template.php
 150                                 body.toggleClass( 'custom-background', !! ( color() || image() ) );
 151
 152                                 if ( color() )
 153                                         css += 'background-color: ' + color() + ';';
 154
 155                                 if ( image() ) {
 156                                         css += 'background-image: url("' + image() + '");';
 157                                         css += 'background-position: top ' + position_x() + ';';
 158                                         css += 'background-repeat: ' + repeat() + ';';
 159                                         css += 'background-attachment: ' + attachment() + ';';
 160                                 }
 161
 162                                 // Refresh the stylesheet by removing and recreating it.
 163                                 style.remove();
 164                                 style = $('<style type="text/css" id="custom-background-css">body.custom-background { ' + css + ' }</style>').appendTo( head );
 165                         };
 166
 167                         $.each( arguments, function() {
 168                                 this.bind( update );
 169                         });
 170                 });
 171
 172                 api.trigger( 'preview-ready' );
 173         });
 174
 175 })( wp, jQuery );