src/core/ready.js

   1 define([
   2         "../core",
   3         "../core/init",
   4         "../deferred"
   5 ], function( jQuery ) {
   6
   7 // The deferred used on DOM ready
   8 var readyList;
   9
  10 jQuery.fn.ready = function( fn ) {
  11         // Add the callback
  12         jQuery.ready.promise().done( fn );
  13
  14         return this;
  15 };
  16
  17 jQuery.extend({
  18         // Is the DOM ready to be used? Set to true once it occurs.
  19         isReady: false,
  20
  21         // A counter to track how many items to wait for before
  22         // the ready event fires. See #6781
  23         readyWait: 1,
  24
  25         // Hold (or release) the ready event
  26         holdReady: function( hold ) {
  27                 if ( hold ) {
  28                         jQuery.readyWait++;
  29                 } else {
  30                         jQuery.ready( true );
  31                 }
  32         },
  33
  34         // Handle when the DOM is ready
  35         ready: function( wait ) {
  36
  37                 // Abort if there are pending holds or we're already ready
  38                 if ( wait === true ? --jQuery.readyWait : jQuery.isReady ) {
  39                         return;
  40                 }
  41
  42                 // Make sure body exists, at least, in case IE gets a little overzealous (ticket #5443).
  43                 if ( !document.body ) {
  44                         return setTimeout( jQuery.ready );
  45                 }
  46
  47                 // Remember that the DOM is ready
  48                 jQuery.isReady = true;
  49
  50                 // If a normal DOM Ready event fired, decrement, and wait if need be
  51                 if ( wait !== true && --jQuery.readyWait > 0 ) {
  52                         return;
  53                 }
  54
  55                 // If there are functions bound, to execute
  56                 readyList.resolveWith( document, [ jQuery ] );
  57
  58                 // Trigger any bound ready events
  59                 if ( jQuery.fn.triggerHandler ) {
  60                         jQuery( document ).triggerHandler( "ready" );
  61                         jQuery( document ).off( "ready" );
  62                 }
  63         }
  64 });
  65
  66 /**
  67  * Clean-up method for dom ready events
  68  */
  69 function detach() {
  70         if ( document.addEventListener ) {
  71                 document.removeEventListener( "DOMContentLoaded", completed, false );
  72                 window.removeEventListener( "load", completed, false );
  73
  74         } else {
  75                 document.detachEvent( "onreadystatechange", completed );
  76                 window.detachEvent( "onload", completed );
  77         }
  78 }
  79
  80 /**
  81  * The ready event handler and self cleanup method
  82  */
  83 function completed() {
  84         // readyState === "complete" is good enough for us to call the dom ready in oldIE
  85         if ( document.addEventListener ||
  86                 event.type === "load" ||
  87                 document.readyState === "complete" ) {
  88
  89                 detach();
  90                 jQuery.ready();
  91         }
  92 }
  93
  94 jQuery.ready.promise = function( obj ) {
  95         if ( !readyList ) {
  96
  97                 readyList = jQuery.Deferred();
  98
  99                 // Catch cases where $(document).ready() is called
 100                 // after the browser event has already occurred.
 101                 // we once tried to use readyState "interactive" here,
 102                 // but it caused issues like the one
 103                 // discovered by ChrisS here:
 104                 // http://bugs.jquery.com/ticket/12282#comment:15
 105                 if ( document.readyState === "complete" ) {
 106                         // Handle it asynchronously to allow scripts the opportunity to delay ready
 107                         setTimeout( jQuery.ready );
 108
 109                 // Standards-based browsers support DOMContentLoaded
 110                 } else if ( document.addEventListener ) {
 111                         // Use the handy event callback
 112                         document.addEventListener( "DOMContentLoaded", completed, false );
 113
 114                         // A fallback to window.onload, that will always work
 115                         window.addEventListener( "load", completed, false );
 116
 117                 // If IE event model is used
 118                 } else {
 119                         // Ensure firing before onload, maybe late but safe also for iframes
 120                         document.attachEvent( "onreadystatechange", completed );
 121
 122                         // A fallback to window.onload, that will always work
 123                         window.attachEvent( "onload", completed );
 124
 125                         // If IE and not a frame
 126                         // continually check to see if the document is ready
 127                         var top = false;
 128
 129                         try {
 130                                 top = window.frameElement == null && document.documentElement;
 131                         } catch ( e ) {}
 132
 133                         if ( top && top.doScroll ) {
 134                                 (function doScrollCheck() {
 135                                         if ( !jQuery.isReady ) {
 136
 137                                                 try {
 138                                                         // Use the trick by Diego Perini
 139                                                         // http://javascript.nwbox.com/IEContentLoaded/
 140                                                         top.doScroll("left");
 141                                                 } catch ( e ) {
 142                                                         return setTimeout( doScrollCheck, 50 );
 143                                                 }
 144
 145                                                 // detach all dom ready events
 146                                                 detach();
 147
 148                                                 // and execute any waiting functions
 149                                                 jQuery.ready();
 150                                         }
 151                                 })();
 152                         }
 153                 }
 154         }
 155         return readyList.promise( obj );
 156 };
 157
 158 });