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 Date.now(); };
  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  * - ECMAScript 5
  30  * - DOM Level 4 & Selectors API Level 1
  31  * - HTML5 & Web Storage
  32  * - DOM Level 2 Events
  33  *
  34  * Browsers we support in our modern run-time (Grade A):
  35  * - Chrome 13+
  36  * - IE 10+
  37  * - Firefox 4+
  38  * - Safari 5+
  39  * - Opera 12.10+
  40  * - Mobile Safari 5.1+ (iOS 5+)
  41  * - Android 4.1+
  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  * - Mobile Safari 5.0+ (iOS 4+)
  50  * - Android 2.0+
  51  * - WebOS < 1.5
  52  * - PlayStation
  53  * - Symbian-based browsers
  54  * - NetFront-based browser
  55  * - Opera Mini
  56  * - Nokia's Ovi Browser
  57  * - MeeGo's browser
  58  * - Google Glass
  59  * - UC Mini (speed mode on)
  60  *
  61  * Other browsers that pass the check are considered Grade X.
  62  *
  63  * @param {string} [str] User agent, defaults to navigator.userAgent
  64  * @return {boolean} User agent is compatible with MediaWiki JS
  65  */
  66 function isCompatible( str ) {
  67         var ua = str || navigator.userAgent;
  68         return !!(
  69                 // http://caniuse.com/#feat=es5
  70                 // http://caniuse.com/#feat=use-strict
  71                 // http://caniuse.com/#feat=json / https://phabricator.wikimedia.org/T141344#2784065
  72                 ( function () {
  73                         'use strict';
  74                         return !this && !!Function.prototype.bind && !!window.JSON;
  75                 }() ) &&
  76
  77                 // http://caniuse.com/#feat=queryselector
  78                 'querySelector' in document &&
  79
  80                 // http://caniuse.com/#feat=namevalue-storage
  81                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  82                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  83                 'localStorage' in window &&
  84
  85                 // http://caniuse.com/#feat=addeventlistener
  86                 'addEventListener' in window &&
  87
  88                 // Hardcoded exceptions for browsers that pass the requirement but we don't want to
  89                 // support in the modern run-time.
  90                 // Note: Please extend the regex instead of adding new ones
  91                 !(
  92                         ua.match( /webOS\/1\.[0-4]|SymbianOS|Series60|NetFront|Opera Mini|S40OviBrowser|MeeGo|Android.+Glass|^Mozilla\/5\.0 .+ Gecko\/$|googleweblight/ ) ||
  93                         ua.match( /PlayStation/i )
  94                 )
  95         );
  96 }
  97
  98 // Conditional script injection
  99 ( function () {
 100         var NORLQ, script;
 101         if ( !isCompatible() ) {
 102                 // Undo class swapping in case of an unsupported browser.
 103                 // See ResourceLoaderClientHtml::getDocumentAttributes().
 104                 document.documentElement.className = document.documentElement.className
 105                         .replace( /(^|\s)client-js(\s|$)/, '$1client-nojs$2' );
 106
 107                 NORLQ = window.NORLQ || [];
 108                 while ( NORLQ.length ) {
 109                         NORLQ.shift()();
 110                 }
 111                 window.NORLQ = {
 112                         push: function ( fn ) {
 113                                 fn();
 114                         }
 115                 };
 116
 117                 // Clear and disable the other queue
 118                 window.RLQ = {
 119                         // No-op
 120                         push: function () {}
 121                 };
 122
 123                 return;
 124         }
 125
 126         /**
 127          * The $CODE and $VARS placeholders are substituted in ResourceLoaderStartUpModule.php.
 128          */
 129         function startUp() {
 130                 mw.config = new mw.Map( $VARS.wgLegacyJavaScriptGlobals );
 131
 132                 $CODE.registrations();
 133
 134                 mw.config.set( $VARS.configuration );
 135
 136                 // Must be after mw.config.set because these callbacks may use mw.loader which
 137                 // needs to have values 'skin', 'debug' etc. from mw.config.
 138                 // eslint-disable-next-line vars-on-top
 139                 var RLQ = window.RLQ || [];
 140                 while ( RLQ.length ) {
 141                         RLQ.shift()();
 142                 }
 143                 window.RLQ = {
 144                         push: function ( fn ) {
 145                                 fn();
 146                         }
 147                 };
 148
 149                 // Clear and disable the other queue
 150                 window.NORLQ = {
 151                         // No-op
 152                         push: function () {}
 153                 };
 154         }
 155
 156         script = document.createElement( 'script' );
 157         script.src = $VARS.baseModulesUri;
 158         script.onload = script.onreadystatechange = function () {
 159                 if ( !script.readyState || /loaded|complete/.test( script.readyState ) ) {
 160                         // Clean up
 161                         script.onload = script.onreadystatechange = null;
 162                         script = null;
 163                         // Callback
 164                         startUp();
 165                 }
 166         };
 167         document.getElementsByTagName( 'head' )[ 0 ].appendChild( script );
 168 }() );