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, mwNow, isCompatible, $VARS, $CODE */
   9
  10 // Define now() here to ensure valid comparison with mediaWikiLoadEnd (T153819).
  11 window.mwNow = ( function () {
  12         var perf = window.performance,
  13                 navStart = perf && perf.timing && perf.timing.navigationStart;
  14         return navStart && typeof perf.now === 'function' ?
  15                 function () { return navStart + perf.now(); } :
  16                 function () { return Date.now(); };
  17 }() );
  18
  19 /**
  20  * See <https://www.mediawiki.org/wiki/Compatibility#Browsers>
  21  *
  22  * Capabilities required for modern run-time:
  23  * - ECMAScript 5
  24  * - DOM Level 4 & Selectors API Level 1
  25  * - HTML5 & Web Storage
  26  * - DOM Level 2 Events
  27  *
  28  * Browsers we support in our modern run-time (Grade A):
  29  * - Chrome 13+
  30  * - IE 11+
  31  * - Firefox 4+
  32  * - Safari 5+
  33  * - Opera 15+
  34  * - Mobile Safari 6.0+ (iOS 6+)
  35  * - Android 4.1+
  36  *
  37  * Browsers we support in our no-javascript run-time (Grade C):
  38  * - Chrome 1+
  39  * - IE 6+
  40  * - Firefox 3+
  41  * - Safari 3+
  42  * - Opera 15+
  43  * - Mobile Safari 5.0+ (iOS 4+)
  44  * - Android 2.0+
  45  * - WebOS < 1.5
  46  * - PlayStation
  47  * - Symbian-based browsers
  48  * - NetFront-based browser
  49  * - Opera Mini
  50  * - Nokia's Ovi Browser
  51  * - MeeGo's browser
  52  * - Google Glass
  53  * - UC Mini (speed mode on)
  54  *
  55  * Other browsers that pass the check are considered Grade X.
  56  *
  57  * @param {string} [str] User agent, defaults to navigator.userAgent
  58  * @return {boolean} User agent is compatible with MediaWiki JS
  59  */
  60 window.isCompatible = function ( str ) {
  61         var ua = str || navigator.userAgent;
  62         return !!(
  63                 // https://caniuse.com/#feat=es5
  64                 // https://caniuse.com/#feat=use-strict
  65                 // https://caniuse.com/#feat=json / https://phabricator.wikimedia.org/T141344#2784065
  66                 ( function () {
  67                         'use strict';
  68                         return !this && !!Function.prototype.bind && !!window.JSON;
  69                 }() ) &&
  70
  71                 // https://caniuse.com/#feat=queryselector
  72                 'querySelector' in document &&
  73
  74                 // https://caniuse.com/#feat=namevalue-storage
  75                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  76                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  77                 'localStorage' in window &&
  78
  79                 // https://caniuse.com/#feat=addeventlistener
  80                 'addEventListener' in window &&
  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( /MSIE 10|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         window.mediaWikiLoadStart = mwNow();
 151         if ( window.performance && performance.mark ) {
 152                 performance.mark( 'mwStartup' );
 153         }
 154         script = document.createElement( 'script' );
 155         script.src = $VARS.baseModulesUri;
 156         script.onload = function () {
 157                 // Clean up
 158                 script.onload = null;
 159                 script = null;
 160                 // Callback
 161                 startUp();
 162         };
 163         document.head.appendChild( script );
 164 }() );