resources/src/mediawiki/mediawiki.storage.js

   1 ( function ( mw ) {
   2         'use strict';
   3
   4         // Catch exceptions to avoid fatal in Chrome's "Block data storage" mode
   5         // which throws when accessing the localStorage property itself, as opposed
   6         // to the standard behaviour of throwing on getItem/setItem. (T148998)
   7         var
   8                 localStorage = ( function () {
   9                         try {
  10                                 return window.localStorage;
  11                         } catch ( e ) {}
  12                 }() ),
  13                 sessionStorage = ( function () {
  14                         try {
  15                                 return window.sessionStorage;
  16                         } catch ( e ) {}
  17                 }() );
  18
  19         /**
  20          * A wrapper for an HTML5 Storage interface (`localStorage` or `sessionStorage`)
  21          * that is safe to call on all browsers.
  22          *
  23          * @class mw.SafeStorage
  24          * @private
  25          * @param {Object|undefined} store The Storage instance to wrap around
  26          */
  27         function SafeStorage( store ) {
  28                 this.store = store;
  29         }
  30
  31         /**
  32          * Retrieve value from device storage.
  33          *
  34          * @param {string} key Key of item to retrieve
  35          * @return {string|boolean} False when localStorage not available, otherwise string
  36          */
  37         SafeStorage.prototype.get = function ( key ) {
  38                 try {
  39                         return this.store.getItem( key );
  40                 } catch ( e ) {}
  41                 return false;
  42         };
  43
  44         /**
  45          * Set a value in device storage.
  46          *
  47          * @param {string} key Key name to store under
  48          * @param {string} value Value to be stored
  49          * @return {boolean} Whether the save succeeded or not
  50          */
  51         SafeStorage.prototype.set = function ( key, value ) {
  52                 try {
  53                         this.store.setItem( key, value );
  54                         return true;
  55                 } catch ( e ) {}
  56                 return false;
  57         };
  58
  59         /**
  60          * Remove a value from device storage.
  61          *
  62          * @param {string} key Key of item to remove
  63          * @return {boolean} Whether the save succeeded or not
  64          */
  65         SafeStorage.prototype.remove = function ( key ) {
  66                 try {
  67                         this.store.removeItem( key );
  68                         return true;
  69                 } catch ( e ) {}
  70                 return false;
  71         };
  72
  73         /**
  74          * A wrapper for the HTML5 `localStorage` interface
  75          * that is safe to call on all browsers.
  76          *
  77          * @class
  78          * @singleton
  79          * @extends mw.SafeStorage
  80          */
  81         mw.storage = new SafeStorage( localStorage );
  82
  83         /**
  84          * A wrapper for the HTML5 `sessionStorage` interface
  85          * that is safe to call on all browsers.
  86          *
  87          * @class
  88          * @singleton
  89          * @extends mw.SafeStorage
  90          */
  91         mw.storage.session = new SafeStorage( sessionStorage );
  92
  93 }( mediaWiki ) );