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, mwPerformance, mwNow, isCompatible, $VARS, $CODE */
   9
  10 window.mwPerformance = ( window.performance && performance.mark ) ? performance : {
  11         mark: function () {}
  12 };
  13 // Define now() here to ensure valid comparison with mediaWikiLoadEnd (T153819).
  14 window.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
  22 /**
  23  * See <https://www.mediawiki.org/wiki/Compatibility#Browsers>
  24  *
  25  * Capabilities required for modern run-time:
  26  * - ECMAScript 5
  27  * - DOM Level 4 & Selectors API Level 1
  28  * - HTML5 & Web Storage
  29  * - DOM Level 2 Events
  30  *
  31  * Browsers we support in our modern run-time (Grade A):
  32  * - Chrome 13+
  33  * - IE 11+
  34  * - Firefox 4+
  35  * - Safari 5+
  36  * - Opera 15+
  37  * - Mobile Safari 6.0+ (iOS 6+)
  38  * - Android 4.1+
  39  *
  40  * Browsers we support in our no-javascript run-time (Grade C):
  41  * - Chrome 1+
  42  * - IE 6+
  43  * - Firefox 3+
  44  * - Safari 3+
  45  * - Opera 15+
  46  * - Mobile Safari 5.0+ (iOS 4+)
  47  * - Android 2.0+
  48  * - WebOS < 1.5
  49  * - PlayStation
  50  * - Symbian-based browsers
  51  * - NetFront-based browser
  52  * - Opera Mini
  53  * - Nokia's Ovi Browser
  54  * - MeeGo's browser
  55  * - Google Glass
  56  * - UC Mini (speed mode on)
  57  *
  58  * Other browsers that pass the check are considered Grade X.
  59  *
  60  * @param {string} [str] User agent, defaults to navigator.userAgent
  61  * @return {boolean} User agent is compatible with MediaWiki JS
  62  */
  63 window.isCompatible = function ( str ) {
  64         var ua = str || navigator.userAgent;
  65         return !!(
  66                 // https://caniuse.com/#feat=es5
  67                 // https://caniuse.com/#feat=use-strict
  68                 // https://caniuse.com/#feat=json / https://phabricator.wikimedia.org/T141344#2784065
  69                 ( function () {
  70                         'use strict';
  71                         return !this && !!Function.prototype.bind && !!window.JSON;
  72                 }() ) &&
  73
  74                 // https://caniuse.com/#feat=queryselector
  75                 'querySelector' in document &&
  76
  77                 // https://caniuse.com/#feat=namevalue-storage
  78                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  79                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  80                 'localStorage' in window &&
  81
  82                 // https://caniuse.com/#feat=addeventlistener
  83                 'addEventListener' in window &&
  84
  85                 // Hardcoded exceptions for browsers that pass the requirement but we don't want to
  86                 // support in the modern run-time.
  87                 // Note: Please extend the regex instead of adding new ones
  88                 !(
  89                         ua.match( /MSIE 10|webOS\/1\.[0-4]|SymbianOS|Series60|NetFront|Opera Mini|S40OviBrowser|MeeGo|Android.+Glass|^Mozilla\/5\.0 .+ Gecko\/$|googleweblight/ ) ||
  90                         ua.match( /PlayStation/i )
  91                 )
  92         );
  93 };
  94
  95 // Conditional script injection
  96 ( function () {
  97         var NORLQ, script;
  98         if ( !isCompatible() ) {
  99                 // Undo class swapping in case of an unsupported browser.
 100                 // See ResourceLoaderClientHtml::getDocumentAttributes().
 101                 document.documentElement.className = document.documentElement.className
 102                         .replace( /(^|\s)client-js(\s|$)/, '$1client-nojs$2' );
 103
 104                 NORLQ = window.NORLQ || [];
 105                 while ( NORLQ.length ) {
 106                         NORLQ.shift()();
 107                 }
 108                 window.NORLQ = {
 109                         push: function ( fn ) {
 110                                 fn();
 111                         }
 112                 };
 113
 114                 // Clear and disable the other queue
 115                 window.RLQ = {
 116                         // No-op
 117                         push: function () {}
 118                 };
 119
 120                 return;
 121         }
 122
 123         /**
 124          * The $CODE and $VARS placeholders are substituted in ResourceLoaderStartUpModule.php.
 125          */
 126         function startUp() {
 127                 mw.config = new mw.Map( $VARS.wgLegacyJavaScriptGlobals );
 128
 129                 $CODE.registrations();
 130
 131                 mw.config.set( $VARS.configuration );
 132
 133                 // Must be after mw.config.set because these callbacks may use mw.loader which
 134                 // needs to have values 'skin', 'debug' etc. from mw.config.
 135                 // eslint-disable-next-line vars-on-top
 136                 var RLQ = window.RLQ || [];
 137                 while ( RLQ.length ) {
 138                         RLQ.shift()();
 139                 }
 140                 window.RLQ = {
 141                         push: function ( fn ) {
 142                                 fn();
 143                         }
 144                 };
 145
 146                 // Clear and disable the other queue
 147                 window.NORLQ = {
 148                         // No-op
 149                         push: function () {}
 150                 };
 151         }
 152
 153         window.mediaWikiLoadStart = mwNow();
 154         mwPerformance.mark( 'mwLoadStart' );
 155
 156         script = document.createElement( 'script' );
 157         script.src = $VARS.baseModulesUri;
 158         script.onload = function () {
 159                 // Clean up
 160                 script.onload = null;
 161                 script = null;
 162                 // Callback
 163                 startUp();
 164         };
 165         document.head.appendChild( script );
 166 }() );