resources/src/startup.js

   1 /**
   2  * Code in this file MUST work on even the most ancient of browsers!
   3  *
   4  * This file is where we decide whether to initialise the modern run-time.
   5  */
   6
   7 /* global mw, $VARS, $CODE */
   8
   9 // eslint-disable-next-line no-unused-vars
  10 var mediaWikiLoadStart = ( new Date() ).getTime(),
  11         mwPerformance = ( window.performance && performance.mark ) ? performance : {
  12                 mark: function () {}
  13         };
  14
  15 mwPerformance.mark( 'mwLoadStart' );
  16
  17 /**
  18  * See <https://www.mediawiki.org/wiki/Compatibility#Browsers>
  19  *
  20  * Capabilities required for modern run-time:
  21  * - DOM Level 4 & Selectors API Level 1
  22  * - HTML5 & Web Storage
  23  * - DOM Level 2 Events
  24  *
  25  * Browsers we support in our modern run-time (Grade A):
  26  * - Chrome
  27  * - IE 9+
  28  * - Firefox 3.5+
  29  * - Safari 4+
  30  * - Opera 10.5+
  31  * - Mobile Safari (iOS 1+)
  32  * - Android 2.0+
  33  *
  34  * Browsers we support in our no-javascript run-time (Grade C):
  35  * - IE 6+
  36  * - Firefox 3+
  37  * - Safari 3+
  38  * - Opera 10+
  39  * - WebOS < 1.5
  40  * - PlayStation
  41  * - Symbian-based browsers
  42  * - NetFront-based browser
  43  * - Opera Mini
  44  * - Nokia's Ovi Browser
  45  * - MeeGo's browser
  46  * - Google Glass
  47  *
  48  * Other browsers that pass the check are considered Grade X.
  49  */
  50 function isCompatible( str ) {
  51         var ua = str || navigator.userAgent;
  52         return !!(
  53                 // http://caniuse.com/#feat=queryselector
  54                 'querySelector' in document &&
  55
  56                 // http://caniuse.com/#feat=namevalue-storage
  57                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  58                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  59                 'localStorage' in window &&
  60
  61                 // http://caniuse.com/#feat=addeventlistener
  62                 'addEventListener' in window &&
  63
  64                 // Hardcoded exceptions for browsers that pass the requirement but we don't want to
  65                 // support in the modern run-time.
  66                 !(
  67                         ua.match( /webOS\/1\.[0-4]|SymbianOS|Series60|NetFront|Opera Mini|S40OviBrowser|MeeGo|Android.+Glass/ ) ||
  68                         ua.match( /PlayStation/i ) ||
  69                         // UC Mini (speed mode on)
  70                         ua.match( /^Mozilla\/5\.0 .+ Gecko\/$/ )
  71                 )
  72         );
  73 }
  74
  75 // Conditional script injection
  76 ( function () {
  77         var NORLQ, script;
  78         if ( !isCompatible() ) {
  79                 // Undo class swapping in case of an unsupported browser.
  80                 // See ResourceLoaderClientHtml::getDocumentAttributes().
  81                 document.documentElement.className = document.documentElement.className
  82                         .replace( /(^|\s)client-js(\s|$)/, '$1client-nojs$2' );
  83
  84                 NORLQ = window.NORLQ || [];
  85                 while ( NORLQ.length ) {
  86                         NORLQ.shift()();
  87                 }
  88                 window.NORLQ = {
  89                         push: function ( fn ) {
  90                                 fn();
  91                         }
  92                 };
  93
  94                 // Clear and disable the other queue
  95                 window.RLQ = {
  96                         // No-op
  97                         push: function () {}
  98                 };
  99
 100                 return;
 101         }
 102
 103         /**
 104          * The $CODE and $VARS placeholders are substituted in ResourceLoaderStartUpModule.php.
 105          */
 106         function startUp() {
 107                 mw.config = new mw.Map( $VARS.wgLegacyJavaScriptGlobals );
 108
 109                 $CODE.registrations();
 110
 111                 mw.config.set( $VARS.configuration );
 112
 113                 // Must be after mw.config.set because these callbacks may use mw.loader which
 114                 // needs to have values 'skin', 'debug' etc. from mw.config.
 115                 // eslint-disable-next-line vars-on-top
 116                 var RLQ = window.RLQ || [];
 117                 while ( RLQ.length ) {
 118                         RLQ.shift()();
 119                 }
 120                 window.RLQ = {
 121                         push: function ( fn ) {
 122                                 fn();
 123                         }
 124                 };
 125
 126                 // Clear and disable the other queue
 127                 window.NORLQ = {
 128                         // No-op
 129                         push: function () {}
 130                 };
 131         }
 132
 133         script = document.createElement( 'script' );
 134         script.src = $VARS.baseModulesUri;
 135         script.onload = script.onreadystatechange = function () {
 136                 if ( !script.readyState || /loaded|complete/.test( script.readyState ) ) {
 137                         // Clean up
 138                         script.onload = script.onreadystatechange = null;
 139                         script = null;
 140                         // Callback
 141                         startUp();
 142                 }
 143         };
 144         document.getElementsByTagName( 'head' )[ 0 ].appendChild( script );
 145 }() );