/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
'use strict';
/** @module store/dom */
var utils = require('./../utils.js');
// Imports.
var throwErrorCallback = utils.throwErrorCallback;
var delay = utils.delay;
var localStorage = null;
/** This method is used to override the Date.toJSON method and is called only by
* JSON.stringify. It should never be called directly.
* @summary Converts a Date object into an object representation friendly to JSON serialization.
* @returns {Object} Object that represents the Date.
*/
function domStoreDateToJSON() {
var newValue = { v: this.valueOf(), t: "[object Date]" };
// Date objects might have extra properties on them so we save them.
for (var name in this) {
newValue[name] = this[name];
}
return newValue;
}
/** This method is used during JSON parsing and invoked only by the reviver function.
* It should never be called directly.
* @summary JSON reviver function for converting an object representing a Date in a JSON stream to a Date object
* @param value _
* @param value - Object to convert.
* @returns {Date} Date object.
*/
function domStoreJSONToDate(_, value) {
if (value && value.t === "[object Date]") {
var newValue = new Date(value.v);
for (var name in value) {
if (name !== "t" && name !== "v") {
newValue[name] = value[name];
}
}
value = newValue;
}
return value;
}
/** Qualifies the key with the name of the store.
* @param {Object} store - Store object whose name will be used for qualifying the key.
* @param {String} key - Key string.
* @returns {String} Fully qualified key string.
*/
function qualifyDomStoreKey(store, key) {
return store.name + "#!#" + key;
}
/** Gets the key part of a fully qualified key string.
* @param {Object} store - Store object whose name will be used for qualifying the key.
* @param {String} key - Fully qualified key string.
* @returns {String} Key part string
*/
function unqualifyDomStoreKey(store, key) {
return key.replace(store.name + "#!#", "");
}
/** Constructor for store objects that use DOM storage as the underlying mechanism.
* @class DomStore
* @constructor
* @param {String} name - Store name.
*/
function DomStore(name) {
this.name = name;
}
/** Creates a store object that uses DOM Storage as its underlying mechanism.
* @method module:store/dom~DomStore.create
* @param {String} name - Store name.
* @returns {Object} Store object.
*/
DomStore.create = function (name) {
if (DomStore.isSupported()) {
localStorage = localStorage || window.localStorage;
return new DomStore(name);
}
throw { message: "Web Storage not supported by the browser" };
};
/** Checks whether the underlying mechanism for this kind of store objects is supported by the browser.
* @method DomStore.isSupported
* @returns {Boolean} - True if the mechanism is supported by the browser; otherwise false.
*/
DomStore.isSupported = function () {
return !!window.localStorage;
};
/** Adds a new value identified by a key to the store.
* @method module:store/dom~DomStore#add
* @param {String} key - Key string.
* @param value - Value that is going to be added to the store.
* @param {Function} success - Callback for a successful add operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
* This method errors out if the store already contains the specified key.
*/
DomStore.prototype.add = function (key, value, success, error) {
error = error || this.defaultError;
var store = this;
this.contains(key, function (contained) {
if (!contained) {
store.addOrUpdate(key, value, success, error);
} else {
delay(error, { message: "key already exists", key: key });
}
}, error);
};
/** This method will overwrite the key's current value if it already exists in the store; otherwise it simply adds the new key and value.
* @summary Adds or updates a value identified by a key to the store.
* @method module:store/dom~DomStore#addOrUpdate
* @param {String} key - Key string.
* @param value - Value that is going to be added or updated to the store.
* @param {Function} success - Callback for a successful add or update operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
*/
DomStore.prototype.addOrUpdate = function (key, value, success, error) {
error = error || this.defaultError;
if (key instanceof Array) {
error({ message: "Array of keys not supported" });
} else {
var fullKey = qualifyDomStoreKey(this, key);
var oldDateToJSON = Date.prototype.toJSON;
try {
var storedValue = value;
if (storedValue !== undefined) {
// Dehydrate using json
Date.prototype.toJSON = domStoreDateToJSON;
storedValue = window.JSON.stringify(value);
}
// Save the json string.
localStorage.setItem(fullKey, storedValue);
delay(success, key, value);
}
catch (e) {
if (e.code === 22 || e.number === 0x8007000E) {
delay(error, { name: "QUOTA_EXCEEDED_ERR", error: e });
} else {
delay(error, e);
}
}
finally {
Date.prototype.toJSON = oldDateToJSON;
}
}
};
/** In case of an error, this method will not restore any keys that might have been deleted at that point.
* @summary Removes all the data associated with this store object.
* @method module:store/dom~DomStore#clear
* @param {Function} success - Callback for a successful clear operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
*/
DomStore.prototype.clear = function (success, error) {
error = error || this.defaultError;
try {
var i = 0, len = localStorage.length;
while (len > 0 && i < len) {
var fullKey = localStorage.key(i);
var key = unqualifyDomStoreKey(this, fullKey);
if (fullKey !== key) {
localStorage.removeItem(fullKey);
len = localStorage.length;
} else {
i++;
}
}
delay(success);
}
catch (e) {
delay(error, e);
}
};
/** This function does nothing in DomStore as it does not have a connection model
* @method module:store/dom~DomStore#close
*/
DomStore.prototype.close = function () {
};
/** Checks whether a key exists in the store.
* @method module:store/dom~DomStore#contains
* @param {String} key - Key string.
* @param {Function} success - Callback indicating whether the store contains the key or not.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
*/
DomStore.prototype.contains = function (key, success, error) {
error = error || this.defaultError;
try {
var fullKey = qualifyDomStoreKey(this, key);
var value = localStorage.getItem(fullKey);
delay(success, value !== null);
} catch (e) {
delay(error, e);
}
};
DomStore.prototype.defaultError = throwErrorCallback;
/** Gets all the keys that exist in the store.
* @method module:store/dom~DomStore#getAllKeys
* @param {Function} success - Callback for a successful get operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
*/
DomStore.prototype.getAllKeys = function (success, error) {
error = error || this.defaultError;
var results = [];
var i, len;
try {
for (i = 0, len = localStorage.length; i < len; i++) {
var fullKey = localStorage.key(i);
var key = unqualifyDomStoreKey(this, fullKey);
if (fullKey !== key) {
results.push(key);
}
}
delay(success, results);
}
catch (e) {
delay(error, e);
}
};
/** Identifies the underlying mechanism used by the store.*/
DomStore.prototype.mechanism = "dom";
/** Reads the value associated to a key in the store.
* @method module:store/dom~DomStore#read
* @param {String} key - Key string.
* @param {Function} success - Callback for a successful reads operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
*/
DomStore.prototype.read = function (key, success, error) {
error = error || this.defaultError;
if (key instanceof Array) {
error({ message: "Array of keys not supported" });
} else {
try {
var fullKey = qualifyDomStoreKey(this, key);
var value = localStorage.getItem(fullKey);
if (value !== null && value !== "undefined") {
// Hydrate using json
value = window.JSON.parse(value, domStoreJSONToDate);
}
else {
value = undefined;
}
delay(success, key, value);
} catch (e) {
delay(error, e);
}
}
};
/** Removes a key and its value from the store.
* @method module:store/dom~DomStore#remove
* @param {String} key - Key string.
* @param {Function} success - Callback for a successful remove operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked.
*/
DomStore.prototype.remove = function (key, success, error) {
error = error || this.defaultError;
if (key instanceof Array) {
error({ message: "Batches not supported" });
} else {
try {
var fullKey = qualifyDomStoreKey(this, key);
localStorage.removeItem(fullKey);
delay(success);
} catch (e) {
delay(error, e);
}
}
};
/** Updates the value associated to a key in the store.
* @method module:store/dom~DomStore#update
* @param {String} key - Key string.
* @param value - New value.
* @param {Function} success - Callback for a successful update operation.
* @param {Function} [error] - Callback for handling errors. If not specified then store.defaultError is invoked
* This method errors out if the specified key is not found in the store.
*/
DomStore.prototype.update = function (key, value, success, error) {
error = error || this.defaultError;
var store = this;
this.contains(key, function (contained) {
if (contained) {
store.addOrUpdate(key, value, success, error);
} else {
delay(error, { message: "key not found", key: key });
}
}, error);
};
module.exports = DomStore;