michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["GlobalState"];
michael@0: 
michael@0: const EXPORTED_METHODS = ["getState", "clear", "get", "set", "delete", "setFromState"];
michael@0: /**
michael@0:  * Module that contains global session data.
michael@0:  */
michael@0: function GlobalState() {
michael@0:   let internal = new GlobalStateInternal();
michael@0:   let external = {};
michael@0:   for (let method of EXPORTED_METHODS) {
michael@0:     external[method] = internal[method].bind(internal);
michael@0:   }
michael@0:   return Object.freeze(external);
michael@0: }
michael@0: 
michael@0: function GlobalStateInternal() {
michael@0:   // Storage for global state.
michael@0:   this.state = {};
michael@0: }
michael@0: 
michael@0: GlobalStateInternal.prototype = {
michael@0:   /**
michael@0:    * Get all value from the global state.
michael@0:    */
michael@0:   getState: function() {
michael@0:     return this.state;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Clear all currently stored global state.
michael@0:    */
michael@0:   clear: function() {
michael@0:     this.state = {};
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Retrieve a value from the global state.
michael@0:    *
michael@0:    * @param aKey
michael@0:    *        A key the value is stored under.
michael@0:    * @return The value stored at aKey, or an empty string if no value is set.
michael@0:    */
michael@0:   get: function(aKey) {
michael@0:     return this.state[aKey] || "";
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Set a global value.
michael@0:    *
michael@0:    * @param aKey
michael@0:    *        A key to store the value under.
michael@0:    */
michael@0:   set: function(aKey, aStringValue) {
michael@0:     this.state[aKey] = aStringValue;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Delete a global value.
michael@0:    *
michael@0:    * @param aKey
michael@0:    *        A key to delete the value for.
michael@0:    */
michael@0:   delete: function(aKey) {
michael@0:     delete this.state[aKey];
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Set the current global state from a state object. Any previous global
michael@0:    * state will be removed, even if the new state does not contain a matching
michael@0:    * key.
michael@0:    *
michael@0:    * @param aState
michael@0:    *        A state object to extract global state from to be set.
michael@0:    */
michael@0:   setFromState: function (aState) {
michael@0:     this.state = (aState && aState.global) || {};
michael@0:   }
michael@0: };