resources/src/startup/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  */
   6 /* eslint-disable no-implicit-globals, vars-on-top, no-unmodified-loop-condition */
   7 /* global $VARS, $CODE */
   8
   9 /**
  10  * See <https://www.mediawiki.org/wiki/Compatibility#Browsers>
  11  *
  12  * Capabilities required for modern run-time:
  13  * - ECMAScript 5
  14  * - DOM Level 4 & Selectors API Level 1
  15  * - HTML5 & Web Storage
  16  * - DOM Level 2 Events
  17  *
  18  * Browsers we support in our modern run-time (Grade A):
  19  * - Chrome 13+
  20  * - IE 11+
  21  * - Firefox 4+
  22  * - Safari 5+
  23  * - Opera 15+
  24  * - Mobile Safari 6.0+ (iOS 6+)
  25  * - Android 4.1+
  26  *
  27  * Browsers we support in our no-javascript run-time (Grade C):
  28  * - Chrome 1+
  29  * - IE 6+
  30  * - Firefox 3+
  31  * - Safari 3+
  32  * - Opera 15+
  33  * - Mobile Safari 5.0+ (iOS 4+)
  34  * - Android 2.0+
  35  * - WebOS < 1.5
  36  * - PlayStation
  37  * - Symbian-based browsers
  38  * - NetFront-based browser
  39  * - Opera Mini
  40  * - Nokia's Ovi Browser
  41  * - MeeGo's browser
  42  * - Google Glass
  43  * - UC Mini (speed mode on)
  44  *
  45  * Other browsers that pass the check are considered Grade X.
  46  *
  47  * @private
  48  * @param {string} ua User agent string
  49  * @return {boolean} User agent is compatible with MediaWiki JS
  50  */
  51 function isCompatible( ua ) {
  52         return !!(
  53                 // https://caniuse.com/#feat=es5
  54                 // https://caniuse.com/#feat=use-strict
  55                 // https://caniuse.com/#feat=json / https://phabricator.wikimedia.org/T141344#2784065
  56                 ( function () {
  57                         'use strict';
  58                         return !this && Function.prototype.bind && window.JSON;
  59                 }() ) &&
  60
  61                 // https://caniuse.com/#feat=queryselector
  62                 'querySelector' in document &&
  63
  64                 // https://caniuse.com/#feat=namevalue-storage
  65                 // https://developer.blackberry.com/html5/apis/v1_0/localstorage.html
  66                 // https://blog.whatwg.org/this-week-in-html-5-episode-30
  67                 'localStorage' in window &&
  68
  69                 // https://caniuse.com/#feat=addeventlistener
  70                 'addEventListener' in window &&
  71
  72                 // Hardcoded exceptions for browsers that pass the requirement but we don't
  73                 // want to support in the modern run-time.
  74                 //
  75                 // Please extend the regex instead of adding new ones!
  76                 // And add a test case to startup.test.js
  77                 !ua.match( /MSIE 10|webOS\/1\.[0-4]|SymbianOS|Series60|NetFront|Opera Mini|S40OviBrowser|MeeGo|Android.+Glass|^Mozilla\/5\.0 .+ Gecko\/$|googleweblight|PLAYSTATION|PlayStation/ )
  78         );
  79 }
  80
  81 if ( !isCompatible( navigator.userAgent ) ) {
  82         // Handle Grade C
  83         // Undo speculative Grade A <html> class. See ResourceLoaderClientHtml::getDocumentAttributes().
  84         document.documentElement.className = document.documentElement.className
  85                 .replace( /(^|\s)client-js(\s|$)/, '$1client-nojs$2' );
  86
  87         // Process any callbacks for Grade C
  88         while ( window.NORLQ && window.NORLQ[ 0 ] ) {
  89                 window.NORLQ.shift()();
  90         }
  91         window.NORLQ = {
  92                 push: function ( fn ) {
  93                         fn();
  94                 }
  95         };
  96
  97         // Clear and disable the Grade A queue
  98         window.RLQ = {
  99                 push: function () {}
 100         };
 101 } else {
 102         // Handle Grade A
 103
 104         if ( window.performance && performance.mark ) {
 105                 performance.mark( 'mwStartup' );
 106         }
 107
 108         // This embeds mediawiki.js, which defines 'mw' and 'mw.loader'.
 109         $CODE.defineLoader();
 110
 111         /**
 112          * The $CODE and $VARS placeholders are substituted in ResourceLoaderStartUpModule.php.
 113          */
 114         ( function () {
 115                 /* global mw */
 116                 mw.config = new mw.Map( $VARS.wgLegacyJavaScriptGlobals );
 117
 118                 $CODE.registrations();
 119
 120                 mw.config.set( $VARS.configuration );
 121
 122                 // Process callbacks for Grade A
 123                 var queue = window.RLQ;
 124                 // Replace RLQ placeholder from ResourceLoaderClientHtml with an implementation
 125                 // that executes simple callbacks, but continues to store callbacks that require
 126                 // modules.
 127                 window.RLQ = [];
 128                 /* global RLQ */
 129                 RLQ.push = function ( fn ) {
 130                         if ( typeof fn === 'function' ) {
 131                                 fn();
 132                         } else {
 133                                 // This callback requires a module, handled in mediawiki.base.
 134                                 RLQ[ RLQ.length ] = fn;
 135                         }
 136                 };
 137                 while ( queue && queue[ 0 ] ) {
 138                         // Re-use our new push() method
 139                         RLQ.push( queue.shift() );
 140                 }
 141
 142                 // Clear and disable the Grade C queue
 143                 window.NORLQ = {
 144                         push: function () {}
 145                 };
 146         }() );
 147 }