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 var mwPerformance = ( window.performance && performance.mark ) ? performance : {
  10                 mark: function () {}
  11         },
  12         // Define now() here to ensure valid comparison with mediaWikiLoadEnd (T153819).
  13         mwNow = ( function () {
  14                 var perf = window.performance,
  15                         navStart = perf && perf.timing && perf.timing.navigationStart;
  16                 return navStart && typeof perf.now === 'function' ?
  17                         function () { return navStart + perf.now(); } :
  18                         function () { return +new Date(); };
  19         }() ),
  20         // eslint-disable-next-line no-unused-vars
  21         mediaWikiLoadStart = mwNow();
  22
  23 mwPerformance.mark( 'mwLoadStart' );
  24
  25 /**
  26  * See <https://www.mediawiki.org/wiki/Compatibility#Browsers>
  27  *
  28  * Capabilities required for modern run-time:
  29  * - DOM Level 4 & Selectors API Level 1
  30  * - HTML5 & Web Storage
  31  * - DOM Level 2 Events
  32  * - JSON
  33  *
  34  * Browsers we support in our modern run-time (Grade A):
  35  * - Chrome 4+
  36  * - IE 9+
  37  * - Firefox 3.5+
  38  * - Safari 5+
  39  * - Opera 10.5+
  40  * - Mobile Safari (iOS 4+)
  41  * - Android 2.0+
  42  *
  43  * Browsers we support in our no-javascript run-time (Grade C):
  44  * - Chrome 1+
  45  * - IE 6+
  46  * - Firefox 3+
  47  * - Safari 3+
  48  * - Opera 10+
  49  * - WebOS < 1.5
  50  * - PlayStation
  51  * - Symbian-based browsers
  52  * - NetFront-based browser
  53  * - Opera Mini
  54  * - Nokia's Ovi Browser
  55  * - MeeGo's browser
  56  * - Google Glass
  57  * - UC Mini (speed mode on)
  58  *
  59  * Other browsers that pass the check are considered Grade X.
  60  *
  61  * @param {string} [str] User agent, defaults to navigator.userAgent
  62  * @return {boolean} User agent is compatible with MediaWiki JS
  63  */
  64 function isCompatible( str ) {
  65         var ua = str || navigator.userAgent;
  66         return !!(
  67                 // http://caniuse.com/#feat=queryselector
  68                 'querySelector' in document &&
  69
  70                 // http://caniuse.com/#feat=namevalue-storage
  71                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  72                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  73                 'localStorage' in window &&
  74
  75                 // http://caniuse.com/#feat=addeventlistener
  76                 'addEventListener' in window &&
  77
  78                 // http://caniuse.com/#feat=json
  79                 // https://phabricator.wikimedia.org/T141344#2784065
  80                 ( window.JSON && JSON.stringify && JSON.parse ) &&
  81
  82                 // Hardcoded exceptions for browsers that pass the requirement but we don't want to
  83                 // support in the modern run-time.
  84                 // Note: Please extend the regex instead of adding new ones
  85                 !(
  86                         ua.match( /webOS\/1\.[0-4]|SymbianOS|Series60|NetFront|Opera Mini|S40OviBrowser|MeeGo|Android.+Glass|^Mozilla\/5\.0 .+ Gecko\/$|googleweblight/ ) ||
  87                         ua.match( /PlayStation/i )
  88                 )
  89         );
  90 }
  91
  92 // Conditional script injection
  93 ( function () {
  94         var NORLQ, script;
  95         if ( !isCompatible() ) {
  96                 // Undo class swapping in case of an unsupported browser.
  97                 // See ResourceLoaderClientHtml::getDocumentAttributes().
  98                 document.documentElement.className = document.documentElement.className
  99                         .replace( /(^|\s)client-js(\s|$)/, '$1client-nojs$2' );
 100
 101                 NORLQ = window.NORLQ || [];
 102                 while ( NORLQ.length ) {
 103                         NORLQ.shift()();
 104                 }
 105                 window.NORLQ = {
 106                         push: function ( fn ) {
 107                                 fn();
 108                         }
 109                 };
 110
 111                 // Clear and disable the other queue
 112                 window.RLQ = {
 113                         // No-op
 114                         push: function () {}
 115                 };
 116
 117                 return;
 118         }
 119
 120         /**
 121          * The $CODE and $VARS placeholders are substituted in ResourceLoaderStartUpModule.php.
 122          */
 123         function startUp() {
 124                 mw.config = new mw.Map( $VARS.wgLegacyJavaScriptGlobals );
 125
 126                 $CODE.registrations();
 127
 128                 mw.config.set( $VARS.configuration );
 129
 130                 // Must be after mw.config.set because these callbacks may use mw.loader which
 131                 // needs to have values 'skin', 'debug' etc. from mw.config.
 132                 // eslint-disable-next-line vars-on-top
 133                 var RLQ = window.RLQ || [];
 134                 while ( RLQ.length ) {
 135                         RLQ.shift()();
 136                 }
 137                 window.RLQ = {
 138                         push: function ( fn ) {
 139                                 fn();
 140                         }
 141                 };
 142
 143                 // Clear and disable the other queue
 144                 window.NORLQ = {
 145                         // No-op
 146                         push: function () {}
 147                 };
 148         }
 149
 150         script = document.createElement( 'script' );
 151         script.src = $VARS.baseModulesUri;
 152         script.onload = script.onreadystatechange = function () {
 153                 if ( !script.readyState || /loaded|complete/.test( script.readyState ) ) {
 154                         // Clean up
 155                         script.onload = script.onreadystatechange = null;
 156                         script = null;
 157                         // Callback
 158                         startUp();
 159                 }
 160         };
 161         document.getElementsByTagName( 'head' )[ 0 ].appendChild( script );
 162 }() );