resources/src/startup.js

   1 /**
   2  * This file is where we decide whether to initialise the Grade A run-time.
   3  *
   4  * - Beware: This file MUST parse without errors on even the most ancient of browsers!
   5  * - Beware: Do not call mwNow before the isCompatible() check.
   6  */
   7
   8 /* global mw, $VARS, $CODE */
   9
  10 var mwPerformance = ( window.performance && performance.mark ) ? performance : {
  11                 mark: function () {}
  12         },
  13         // Define now() here to ensure valid comparison with mediaWikiLoadEnd (T153819).
  14         mwNow = ( function () {
  15                 var perf = window.performance,
  16                         navStart = perf && perf.timing && perf.timing.navigationStart;
  17                 return navStart && typeof perf.now === 'function' ?
  18                         function () { return navStart + perf.now(); } :
  19                         function () { return Date.now(); };
  20         }() ),
  21         // eslint-disable-next-line no-unused-vars
  22         mediaWikiLoadStart;
  23
  24 /**
  25  * See <https://www.mediawiki.org/wiki/Compatibility#Browsers>
  26  *
  27  * Capabilities required for modern run-time:
  28  * - ECMAScript 5
  29  * - DOM Level 4 & Selectors API Level 1
  30  * - HTML5 & Web Storage
  31  * - DOM Level 2 Events
  32  *
  33  * Browsers we support in our modern run-time (Grade A):
  34  * - Chrome 13+
  35  * - IE 10+
  36  * - Firefox 4+
  37  * - Safari 5+
  38  * - Opera 12.10+
  39  * - Mobile Safari 5.1+ (iOS 5+)
  40  * - Android 4.1+
  41  *
  42  * Browsers we support in our no-javascript run-time (Grade C):
  43  * - Chrome 1+
  44  * - IE 6+
  45  * - Firefox 3+
  46  * - Safari 3+
  47  * - Opera 10+
  48  * - Mobile Safari 5.0+ (iOS 4+)
  49  * - Android 2.0+
  50  * - WebOS < 1.5
  51  * - PlayStation
  52  * - Symbian-based browsers
  53  * - NetFront-based browser
  54  * - Opera Mini
  55  * - Nokia's Ovi Browser
  56  * - MeeGo's browser
  57  * - Google Glass
  58  * - UC Mini (speed mode on)
  59  *
  60  * Other browsers that pass the check are considered Grade X.
  61  *
  62  * @param {string} [str] User agent, defaults to navigator.userAgent
  63  * @return {boolean} User agent is compatible with MediaWiki JS
  64  */
  65 function isCompatible( str ) {
  66         var ua = str || navigator.userAgent;
  67         return !!(
  68                 // http://caniuse.com/#feat=es5
  69                 // http://caniuse.com/#feat=use-strict
  70                 // http://caniuse.com/#feat=json / https://phabricator.wikimedia.org/T141344#2784065
  71                 ( function () {
  72                         'use strict';
  73                         return !this && !!Function.prototype.bind && !!window.JSON;
  74                 }() ) &&
  75
  76                 // http://caniuse.com/#feat=queryselector
  77                 'querySelector' in document &&
  78
  79                 // http://caniuse.com/#feat=namevalue-storage
  80                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  81                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  82                 'localStorage' in window &&
  83
  84                 // http://caniuse.com/#feat=addeventlistener
  85                 'addEventListener' in window &&
  86
  87                 // Hardcoded exceptions for browsers that pass the requirement but we don't want to
  88                 // support in the modern run-time.
  89                 // Note: Please extend the regex instead of adding new ones
  90                 !(
  91                         ua.match( /webOS\/1\.[0-4]|SymbianOS|Series60|NetFront|Opera Mini|S40OviBrowser|MeeGo|Android.+Glass|^Mozilla\/5\.0 .+ Gecko\/$|googleweblight/ ) ||
  92                         ua.match( /PlayStation/i )
  93                 )
  94         );
  95 }
  96
  97 // Conditional script injection
  98 ( function () {
  99         var NORLQ, script;
 100         if ( !isCompatible() ) {
 101                 // Undo class swapping in case of an unsupported browser.
 102                 // See ResourceLoaderClientHtml::getDocumentAttributes().
 103                 document.documentElement.className = document.documentElement.className
 104                         .replace( /(^|\s)client-js(\s|$)/, '$1client-nojs$2' );
 105
 106                 NORLQ = window.NORLQ || [];
 107                 while ( NORLQ.length ) {
 108                         NORLQ.shift()();
 109                 }
 110                 window.NORLQ = {
 111                         push: function ( fn ) {
 112                                 fn();
 113                         }
 114                 };
 115
 116                 // Clear and disable the other queue
 117                 window.RLQ = {
 118                         // No-op
 119                         push: function () {}
 120                 };
 121
 122                 return;
 123         }
 124
 125         /**
 126          * The $CODE and $VARS placeholders are substituted in ResourceLoaderStartUpModule.php.
 127          */
 128         function startUp() {
 129                 mw.config = new mw.Map( $VARS.wgLegacyJavaScriptGlobals );
 130
 131                 $CODE.registrations();
 132
 133                 mw.config.set( $VARS.configuration );
 134
 135                 // Must be after mw.config.set because these callbacks may use mw.loader which
 136                 // needs to have values 'skin', 'debug' etc. from mw.config.
 137                 // eslint-disable-next-line vars-on-top
 138                 var RLQ = window.RLQ || [];
 139                 while ( RLQ.length ) {
 140                         RLQ.shift()();
 141                 }
 142                 window.RLQ = {
 143                         push: function ( fn ) {
 144                                 fn();
 145                         }
 146                 };
 147
 148                 // Clear and disable the other queue
 149                 window.NORLQ = {
 150                         // No-op
 151                         push: function () {}
 152                 };
 153         }
 154
 155         mediaWikiLoadStart = mwNow();
 156         mwPerformance.mark( 'mwLoadStart' );
 157
 158         script = document.createElement( 'script' );
 159         script.src = $VARS.baseModulesUri;
 160         script.onload = script.onreadystatechange = function () {
 161                 if ( !script.readyState || /loaded|complete/.test( script.readyState ) ) {
 162                         // Clean up
 163                         script.onload = script.onreadystatechange = null;
 164                         script = null;
 165                         // Callback
 166                         startUp();
 167                 }
 168         };
 169         document.getElementsByTagName( 'head' )[ 0 ].appendChild( script );
 170 }() );