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          */
  26
  27         /**
  28          * @ignore
  29          * @param {Object|undefined} store The Storage instance to wrap around
  30          */
  31         function SafeStorage( store ) {
  32                 this.store = store;
  33         }
  34
  35         /**
  36          * Retrieve value from device storage.
  37          *
  38          * @param {string} key Key of item to retrieve
  39          * @return {string|boolean} False when localStorage not available, otherwise string
  40          */
  41         SafeStorage.prototype.get = function ( key ) {
  42                 try {
  43                         return this.store.getItem( key );
  44                 } catch ( e ) {}
  45                 return false;
  46         };
  47
  48         /**
  49           * Set a value in device storage.
  50           *
  51           * @param {string} key Key name to store under
  52           * @param {string} value Value to be stored
  53           * @return {boolean} Whether the save succeeded or not
  54           */
  55         SafeStorage.prototype.set = function ( key, value ) {
  56                 try {
  57                         this.store.setItem( key, value );
  58                         return true;
  59                 } catch ( e ) {}
  60                 return false;
  61         };
  62
  63         /**
  64           * Remove a value from device storage.
  65           *
  66           * @param {string} key Key of item to remove
  67           * @return {boolean} Whether the save succeeded or not
  68           */
  69         SafeStorage.prototype.remove = function ( key ) {
  70                 try {
  71                         this.store.removeItem( key );
  72                         return true;
  73                 } catch ( e ) {}
  74                 return false;
  75         };
  76
  77         /**
  78          * @class
  79          * @singleton
  80          * @extends mw.SafeStorage
  81          */
  82         mw.storage = new SafeStorage( localStorage );
  83
  84         /**
  85          * @class
  86          * @singleton
  87          * @extends mw.SafeStorage
  88          */
  89         mw.storage.session = new SafeStorage( sessionStorage );
  90
  91 }( mediaWiki ) );