/*
* ----------------------------- JSTORAGE -------------------------------------
* Simple local storage wrapper to save data on the browser side, supporting
* all major browsers - IE6+, Firefox2+, Safari4+, Chrome4+ and Opera 10.5+
*
* Author: Andris Reinman, andris.reinman@gmail.com
* Project homepage: www.jstorage.info
*
* Licensed under Unlicense:
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* For more information, please refer to
*/
(function() {
'use strict';
var
/* jStorage version */
JSTORAGE_VERSION = '0.4.10',
/* detect a dollar object or create one if not found */
$ = window.jQuery || window.$ || (window.$ = {}),
/* check for a JSON handling support */
JSON = {
parse: window.JSON && (window.JSON.parse || window.JSON.decode) ||
String.prototype.evalJSON && function(str) {
return String(str).evalJSON();
} ||
$.parseJSON ||
$.evalJSON,
stringify: Object.toJSON ||
window.JSON && (window.JSON.stringify || window.JSON.encode) ||
$.toJSON
};
// Break if no JSON support was found
if (!('parse' in JSON) || !('stringify' in JSON)) {
throw new Error('No JSON support found, include //cdnjs.cloudflare.com/ajax/libs/json2/20110223/json2.js to page');
}
var
/* This is the object, that holds the cached values */
_storage = {
__jstorage_meta: {
CRC32: {}
}
},
/* Actual browser storage (localStorage or globalStorage['domain']) */
_storage_service = {
jStorage: '{}'
},
/* DOM element for older IE versions, holds userData behavior */
_storage_elm = null,
/* How much space does the storage take */
_storage_size = 0,
/* which backend is currently used */
_backend = false,
/* onchange observers */
_observers = {},
/* timeout to wait after onchange event */
_observer_timeout = false,
/* last update time */
_observer_update = 0,
/* pubsub observers */
_pubsub_observers = {},
/* skip published items older than current timestamp */
_pubsub_last = +new Date(),
/* Next check for TTL */
_ttl_timeout,
/**
* XML encoding and decoding as XML nodes can't be JSON'ized
* XML nodes are encoded and decoded if the node is the value to be saved
* but not if it's as a property of another object
* Eg. -
* $.jStorage.set('key', xmlNode); // IS OK
* $.jStorage.set('key', {xml: xmlNode}); // NOT OK
*/
_XMLService = {
/**
* Validates a XML node to be XML
* based on jQuery.isXML function
*/
isXML: function(elm) {
var documentElement = (elm ? elm.ownerDocument || elm : 0).documentElement;
return documentElement ? documentElement.nodeName !== 'HTML' : false;
},
/**
* Encodes a XML node to string
* based on http://www.mercurytide.co.uk/news/article/issues-when-working-ajax/
*/
encode: function(xmlNode) {
if (!this.isXML(xmlNode)) {
return false;
}
try { // Mozilla, Webkit, Opera
return new XMLSerializer().serializeToString(xmlNode);
} catch (E1) {
try { // IE
return xmlNode.xml;
} catch (E2) {}
}
return false;
},
/**
* Decodes a XML node from string
* loosely based on http://outwestmedia.com/jquery-plugins/xmldom/
*/
decode: function(xmlString) {
var dom_parser = ('DOMParser' in window && (new DOMParser()).parseFromString) ||
(window.ActiveXObject && function(_xmlString) {
var xml_doc = new ActiveXObject('Microsoft.XMLDOM');
xml_doc.async = 'false';
xml_doc.loadXML(_xmlString);
return xml_doc;
}),
resultXML;
if (!dom_parser) {
return false;
}
resultXML = dom_parser.call('DOMParser' in window && (new DOMParser()) || window, xmlString, 'text/xml');
return this.isXML(resultXML) ? resultXML : false;
}
};
////////////////////////// PRIVATE METHODS ////////////////////////
/**
* Initialization function. Detects if the browser supports DOM Storage
* or userData behavior and behaves accordingly.
*/
function _init() {
/* Check if browser supports localStorage */
var localStorageReallyWorks = false;
if ('localStorage' in window) {
try {
window.localStorage.setItem('_tmptest', 'tmpval');
localStorageReallyWorks = true;
window.localStorage.removeItem('_tmptest');
} catch (BogusQuotaExceededErrorOnIos5) {
// Thanks be to iOS5 Private Browsing mode which throws
// QUOTA_EXCEEDED_ERRROR DOM Exception 22.
}
}
if (localStorageReallyWorks) {
try {
if (window.localStorage) {
_storage_service = window.localStorage;
_backend = 'localStorage';
_observer_update = _storage_service.jStorage_update;
}
} catch (E3) { /* Firefox fails when touching localStorage and cookies are disabled */ }
}
/* Check if browser supports globalStorage */
else if ('globalStorage' in window) {
try {
if (window.globalStorage) {
if (window.location.hostname == 'localhost') {
_storage_service = window.globalStorage['localhost.localdomain'];
} else {
_storage_service = window.globalStorage[window.location.hostname];
}
_backend = 'globalStorage';
_observer_update = _storage_service.jStorage_update;
}
} catch (E4) { /* Firefox fails when touching localStorage and cookies are disabled */ }
}
/* Check if browser supports userData behavior */
else {
_storage_elm = document.createElement('link');
if (_storage_elm.addBehavior) {
/* Use a DOM element to act as userData storage */
_storage_elm.style.behavior = 'url(#default#userData)';
/* userData element needs to be inserted into the DOM! */
document.getElementsByTagName('head')[0].appendChild(_storage_elm);
try {
_storage_elm.load('jStorage');
} catch (E) {
// try to reset cache
_storage_elm.setAttribute('jStorage', '{}');
_storage_elm.save('jStorage');
_storage_elm.load('jStorage');
}
var data = '{}';
try {
data = _storage_elm.getAttribute('jStorage');
} catch (E5) {}
try {
_observer_update = _storage_elm.getAttribute('jStorage_update');
} catch (E6) {}
_storage_service.jStorage = data;
_backend = 'userDataBehavior';
} else {
_storage_elm = null;
return;
}
}
// Load data from storage
_load_storage();
// remove dead keys
_handleTTL();
// start listening for changes
_setupObserver();
// initialize publish-subscribe service
_handlePubSub();
// handle cached navigation
if ('addEventListener' in window) {
window.addEventListener('pageshow', function(event) {
if (event.persisted) {
_storageObserver();
}
}, false);
}
}
/**
* Reload data from storage when needed
*/
function _reloadData() {
var data = '{}';
if (_backend == 'userDataBehavior') {
_storage_elm.load('jStorage');
try {
data = _storage_elm.getAttribute('jStorage');
} catch (E5) {}
try {
_observer_update = _storage_elm.getAttribute('jStorage_update');
} catch (E6) {}
_storage_service.jStorage = data;
}
_load_storage();
// remove dead keys
_handleTTL();
_handlePubSub();
}
/**
* Sets up a storage change observer
*/
function _setupObserver() {
if (_backend == 'localStorage' || _backend == 'globalStorage') {
if ('addEventListener' in window) {
window.addEventListener('storage', _storageObserver, false);
} else {
document.attachEvent('onstorage', _storageObserver);
}
} else if (_backend == 'userDataBehavior') {
setInterval(_storageObserver, 1000);
}
}
/**
* Fired on any kind of data change, needs to check if anything has
* really been changed
*/
function _storageObserver() {
var updateTime;
// cumulate change notifications with timeout
clearTimeout(_observer_timeout);
_observer_timeout = setTimeout(function() {
if (_backend == 'localStorage' || _backend == 'globalStorage') {
updateTime = _storage_service.jStorage_update;
} else if (_backend == 'userDataBehavior') {
_storage_elm.load('jStorage');
try {
updateTime = _storage_elm.getAttribute('jStorage_update');
} catch (E5) {}
}
if (updateTime && updateTime != _observer_update) {
_observer_update = updateTime;
_checkUpdatedKeys();
}
}, 25);
}
/**
* Reloads the data and checks if any keys are changed
*/
function _checkUpdatedKeys() {
var oldCrc32List = JSON.parse(JSON.stringify(_storage.__jstorage_meta.CRC32)),
newCrc32List;
_reloadData();
newCrc32List = JSON.parse(JSON.stringify(_storage.__jstorage_meta.CRC32));
var key,
updated = [],
removed = [];
for (key in oldCrc32List) {
if (oldCrc32List.hasOwnProperty(key)) {
if (!newCrc32List[key]) {
removed.push(key);
continue;
}
if (oldCrc32List[key] != newCrc32List[key] && String(oldCrc32List[key]).substr(0, 2) == '2.') {
updated.push(key);
}
}
}
for (key in newCrc32List) {
if (newCrc32List.hasOwnProperty(key)) {
if (!oldCrc32List[key]) {
updated.push(key);
}
}
}
_fireObservers(updated, 'updated');
_fireObservers(removed, 'deleted');
}
/**
* Fires observers for updated keys
*
* @param {Array|String} keys Array of key names or a key
* @param {String} action What happened with the value (updated, deleted, flushed)
*/
function _fireObservers(keys, action) {
keys = [].concat(keys || []);
var i, j, len, jlen;
if (action == 'flushed') {
keys = [];
for (var key in _observers) {
if (_observers.hasOwnProperty(key)) {
keys.push(key);
}
}
action = 'deleted';
}
for (i = 0, len = keys.length; i < len; i++) {
if (_observers[keys[i]]) {
for (j = 0, jlen = _observers[keys[i]].length; j < jlen; j++) {
_observers[keys[i]][j](keys[i], action);
}
}
if (_observers['*']) {
for (j = 0, jlen = _observers['*'].length; j < jlen; j++) {
_observers['*'][j](keys[i], action);
}
}
}
}
/**
* Publishes key change to listeners
*/
function _publishChange() {
var updateTime = (+new Date()).toString();
if (_backend == 'localStorage' || _backend == 'globalStorage') {
try {
_storage_service.jStorage_update = updateTime;
} catch (E8) {
// safari private mode has been enabled after the jStorage initialization
_backend = false;
}
} else if (_backend == 'userDataBehavior') {
_storage_elm.setAttribute('jStorage_update', updateTime);
_storage_elm.save('jStorage');
}
_storageObserver();
}
/**
* Loads the data from the storage based on the supported mechanism
*/
function _load_storage() {
/* if jStorage string is retrieved, then decode it */
if (_storage_service.jStorage) {
try {
_storage = JSON.parse(String(_storage_service.jStorage));
} catch (E6) {
_storage_service.jStorage = '{}';
}
} else {
_storage_service.jStorage = '{}';
}
_storage_size = _storage_service.jStorage ? String(_storage_service.jStorage).length : 0;
if (!_storage.__jstorage_meta) {
_storage.__jstorage_meta = {};
}
if (!_storage.__jstorage_meta.CRC32) {
_storage.__jstorage_meta.CRC32 = {};
}
}
/**
* This functions provides the 'save' mechanism to store the jStorage object
*/
function _save() {
_dropOldEvents(); // remove expired events
try {
_storage_service.jStorage = JSON.stringify(_storage);
// If userData is used as the storage engine, additional
if (_storage_elm) {
_storage_elm.setAttribute('jStorage', _storage_service.jStorage);
_storage_elm.save('jStorage');
}
_storage_size = _storage_service.jStorage ? String(_storage_service.jStorage).length : 0;
} catch (E7) { /* probably cache is full, nothing is saved this way*/ }
}
/**
* Function checks if a key is set and is string or numberic
*
* @param {String} key Key name
*/
function _checkKey(key) {
if (typeof key != 'string' && typeof key != 'number') {
throw new TypeError('Key name must be string or numeric');
}
if (key == '__jstorage_meta') {
throw new TypeError('Reserved key name');
}
return true;
}
/**
* Removes expired keys
*/
function _handleTTL() {
var curtime, i, TTL, CRC32, nextExpire = Infinity,
changed = false,
deleted = [];
clearTimeout(_ttl_timeout);
if (!_storage.__jstorage_meta || typeof _storage.__jstorage_meta.TTL != 'object') {
// nothing to do here
return;
}
curtime = +new Date();
TTL = _storage.__jstorage_meta.TTL;
CRC32 = _storage.__jstorage_meta.CRC32;
for (i in TTL) {
if (TTL.hasOwnProperty(i)) {
if (TTL[i] <= curtime) {
delete TTL[i];
delete CRC32[i];
delete _storage[i];
changed = true;
deleted.push(i);
} else if (TTL[i] < nextExpire) {
nextExpire = TTL[i];
}
}
}
// set next check
if (nextExpire != Infinity) {
_ttl_timeout = setTimeout(_handleTTL, Math.min(nextExpire - curtime, 0x7FFFFFFF));
}
// save changes
if (changed) {
_save();
_publishChange();
_fireObservers(deleted, 'deleted');
}
}
/**
* Checks if there's any events on hold to be fired to listeners
*/
function _handlePubSub() {
var i, len;
if (!_storage.__jstorage_meta.PubSub) {
return;
}
var pubelm,
_pubsubCurrent = _pubsub_last;
for (i = len = _storage.__jstorage_meta.PubSub.length - 1; i >= 0; i--) {
pubelm = _storage.__jstorage_meta.PubSub[i];
if (pubelm[0] > _pubsub_last) {
_pubsubCurrent = pubelm[0];
_fireSubscribers(pubelm[1], pubelm[2]);
}
}
_pubsub_last = _pubsubCurrent;
}
/**
* Fires all subscriber listeners for a pubsub channel
*
* @param {String} channel Channel name
* @param {Mixed} payload Payload data to deliver
*/
function _fireSubscribers(channel, payload) {
if (_pubsub_observers[channel]) {
for (var i = 0, len = _pubsub_observers[channel].length; i < len; i++) {
// send immutable data that can't be modified by listeners
try {
_pubsub_observers[channel][i](channel, JSON.parse(JSON.stringify(payload)));
} catch (E) {}
}
}
}
/**
* Remove old events from the publish stream (at least 2sec old)
*/
function _dropOldEvents() {
if (!_storage.__jstorage_meta.PubSub) {
return;
}
var retire = +new Date() - 2000;
for (var i = 0, len = _storage.__jstorage_meta.PubSub.length; i < len; i++) {
if (_storage.__jstorage_meta.PubSub[i][0] <= retire) {
// deleteCount is needed for IE6
_storage.__jstorage_meta.PubSub.splice(i, _storage.__jstorage_meta.PubSub.length - i);
break;
}
}
if (!_storage.__jstorage_meta.PubSub.length) {
delete _storage.__jstorage_meta.PubSub;
}
}
/**
* Publish payload to a channel
*
* @param {String} channel Channel name
* @param {Mixed} payload Payload to send to the subscribers
*/
function _publish(channel, payload) {
if (!_storage.__jstorage_meta) {
_storage.__jstorage_meta = {};
}
if (!_storage.__jstorage_meta.PubSub) {
_storage.__jstorage_meta.PubSub = [];
}
_storage.__jstorage_meta.PubSub.unshift([+new Date(), channel, payload]);
_save();
_publishChange();
}
/**
* JS Implementation of MurmurHash2
*
* SOURCE: https://github.com/garycourt/murmurhash-js (MIT licensed)
*
* @author Gary Court
* @see http://github.com/garycourt/murmurhash-js
* @author Austin Appleby
* @see http://sites.google.com/site/murmurhash/
*
* @param {string} str ASCII only
* @param {number} seed Positive integer only
* @return {number} 32-bit positive integer hash
*/
function murmurhash2_32_gc(str, seed) {
var
l = str.length,
h = seed ^ l,
i = 0,
k;
while (l >= 4) {
k =
((str.charCodeAt(i) & 0xff)) |
((str.charCodeAt(++i) & 0xff) << 8) |
((str.charCodeAt(++i) & 0xff) << 16) |
((str.charCodeAt(++i) & 0xff) << 24);
k = (((k & 0xffff) * 0x5bd1e995) + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16));
k ^= k >>> 24;
k = (((k & 0xffff) * 0x5bd1e995) + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16));
h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16)) ^ k;
l -= 4;
++i;
}
switch (l) {
case 3:
h ^= (str.charCodeAt(i + 2) & 0xff) << 16;
case 2:
h ^= (str.charCodeAt(i + 1) & 0xff) << 8;
case 1:
h ^= (str.charCodeAt(i) & 0xff);
h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16));
}
h ^= h >>> 13;
h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16));
h ^= h >>> 15;
return h >>> 0;
}
////////////////////////// PUBLIC INTERFACE /////////////////////////
$.jStorage = {
/* Version number */
version: JSTORAGE_VERSION,
/**
* Sets a key's value.
*
* @param {String} key Key to set. If this value is not set or not
* a string an exception is raised.
* @param {Mixed} value Value to set. This can be any value that is JSON
* compatible (Numbers, Strings, Objects etc.).
* @param {Object} [options] - possible options to use
* @param {Number} [options.TTL] - optional TTL value, in milliseconds
* @return {Mixed} the used value
*/
set: function(key, value, options) {
_checkKey(key);
options = options || {};
// undefined values are deleted automatically
if (typeof value == 'undefined') {
this.deleteKey(key);
return value;
}
if (_XMLService.isXML(value)) {
value = {
_is_xml: true,
xml: _XMLService.encode(value)
};
} else if (typeof value == 'function') {
return undefined; // functions can't be saved!
} else if (value && typeof value == 'object') {
// clone the object before saving to _storage tree
value = JSON.parse(JSON.stringify(value));
}
_storage[key] = value;
_storage.__jstorage_meta.CRC32[key] = '2.' + murmurhash2_32_gc(JSON.stringify(value), 0x9747b28c);
this.setTTL(key, options.TTL || 0); // also handles saving and _publishChange
_fireObservers(key, 'updated');
return value;
},
/**
* Looks up a key in cache
*
* @param {String} key - Key to look up.
* @param {mixed} def - Default value to return, if key didn't exist.
* @return {Mixed} the key value, default value or null
*/
get: function(key, def) {
_checkKey(key);
if (key in _storage) {
if (_storage[key] && typeof _storage[key] == 'object' && _storage[key]._is_xml) {
return _XMLService.decode(_storage[key].xml);
} else {
return _storage[key];
}
}
return typeof(def) == 'undefined' ? null : def;
},
/**
* Deletes a key from cache.
*
* @param {String} key - Key to delete.
* @return {Boolean} true if key existed or false if it didn't
*/
deleteKey: function(key) {
_checkKey(key);
if (key in _storage) {
delete _storage[key];
// remove from TTL list
if (typeof _storage.__jstorage_meta.TTL == 'object' &&
key in _storage.__jstorage_meta.TTL) {
delete _storage.__jstorage_meta.TTL[key];
}
delete _storage.__jstorage_meta.CRC32[key];
_save();
_publishChange();
_fireObservers(key, 'deleted');
return true;
}
return false;
},
/**
* Sets a TTL for a key, or remove it if ttl value is 0 or below
*
* @param {String} key - key to set the TTL for
* @param {Number} ttl - TTL timeout in milliseconds
* @return {Boolean} true if key existed or false if it didn't
*/
setTTL: function(key, ttl) {
var curtime = +new Date();
_checkKey(key);
ttl = Number(ttl) || 0;
if (key in _storage) {
if (!_storage.__jstorage_meta.TTL) {
_storage.__jstorage_meta.TTL = {};
}
// Set TTL value for the key
if (ttl > 0) {
_storage.__jstorage_meta.TTL[key] = curtime + ttl;
} else {
delete _storage.__jstorage_meta.TTL[key];
}
_save();
_handleTTL();
_publishChange();
return true;
}
return false;
},
/**
* Gets remaining TTL (in milliseconds) for a key or 0 when no TTL has been set
*
* @param {String} key Key to check
* @return {Number} Remaining TTL in milliseconds
*/
getTTL: function(key) {
var curtime = +new Date(),
ttl;
_checkKey(key);
if (key in _storage && _storage.__jstorage_meta.TTL && _storage.__jstorage_meta.TTL[key]) {
ttl = _storage.__jstorage_meta.TTL[key] - curtime;
return ttl || 0;
}
return 0;
},
/**
* Deletes everything in cache.
*
* @return {Boolean} Always true
*/
flush: function() {
_storage = {
__jstorage_meta: {
CRC32: {}
}
};
_save();
_publishChange();
_fireObservers(null, 'flushed');
return true;
},
/**
* Returns a read-only copy of _storage
*
* @return {Object} Read-only copy of _storage
*/
storageObj: function() {
function F() {}
F.prototype = _storage;
return new F();
},
/**
* Returns an index of all used keys as an array
* ['key1', 'key2',..'keyN']
*
* @return {Array} Used keys
*/
index: function() {
var index = [],
i;
for (i in _storage) {
if (_storage.hasOwnProperty(i) && i != '__jstorage_meta') {
index.push(i);
}
}
return index;
},
/**
* How much space in bytes does the storage take?
*
* @return {Number} Storage size in chars (not the same as in bytes,
* since some chars may take several bytes)
*/
storageSize: function() {
return _storage_size;
},
/**
* Which backend is currently in use?
*
* @return {String} Backend name
*/
currentBackend: function() {
return _backend;
},
/**
* Test if storage is available
*
* @return {Boolean} True if storage can be used
*/
storageAvailable: function() {
return !!_backend;
},
/**
* Register change listeners
*
* @param {String} key Key name
* @param {Function} callback Function to run when the key changes
*/
listenKeyChange: function(key, callback) {
_checkKey(key);
if (!_observers[key]) {
_observers[key] = [];
}
_observers[key].push(callback);
},
/**
* Remove change listeners
*
* @param {String} key Key name to unregister listeners against
* @param {Function} [callback] If set, unregister the callback, if not - unregister all
*/
stopListening: function(key, callback) {
_checkKey(key);
if (!_observers[key]) {
return;
}
if (!callback) {
delete _observers[key];
return;
}
for (var i = _observers[key].length - 1; i >= 0; i--) {
if (_observers[key][i] == callback) {
_observers[key].splice(i, 1);
}
}
},
/**
* Subscribe to a Publish/Subscribe event stream
*
* @param {String} channel Channel name
* @param {Function} callback Function to run when the something is published to the channel
*/
subscribe: function(channel, callback) {
channel = (channel || '').toString();
if (!channel) {
throw new TypeError('Channel not defined');
}
if (!_pubsub_observers[channel]) {
_pubsub_observers[channel] = [];
}
_pubsub_observers[channel].push(callback);
},
/**
* Publish data to an event stream
*
* @param {String} channel Channel name
* @param {Mixed} payload Payload to deliver
*/
publish: function(channel, payload) {
channel = (channel || '').toString();
if (!channel) {
throw new TypeError('Channel not defined');
}
_publish(channel, payload);
},
/**
* Reloads the data from browser storage
*/
reInit: function() {
_reloadData();
},
/**
* Removes reference from global objects and saves it as jStorage
*
* @param {Boolean} option if needed to save object as simple 'jStorage' in windows context
*/
noConflict: function(saveInGlobal) {
delete window.$.jStorage;
if (saveInGlobal) {
window.jStorage = this;
}
return this;
}
};
// Initialize jStorage
_init();
})();