documented new features

README.md

@@ -21,26 +21,39 @@ Made fo for Node.JS and Ender.JS (browser-side).
 
     var localStorage = require('localStorage')
       , JsonStorage = require('json-storage')
-      , db = JsonStorage(localStorage, 'my-app-prefix')
+      , store = JsonStorage.create(localStorage, 'my-widget-namespace')
       , myValue = {
             foo: "bar"
           , baz: "quux"
         }
       ;
 
-    db.set('myKey', myValue); 
-    myValue = db.get('myKey');
+    store.set('myKey', myValue); 
+    myValue = store.get('myKey');
 
 API
 ===
 
-  * JsonStorage(DOMStorage, 'application-prefix') // optional prefix
-  * get(key)
-  * set(key, value)
-  * remove(key)
-  * clear()
-  * keys()
-  * size()
+  * `create(DOMStorage, namespace)`
+    * `DOMStorage` should be globalStorage, sessionStorage, or localStorage
+    * `namespace` is optional string which allows multiple non-conflicting storage containers
+  * `get(key)`
+  * `set(key, value)`
+  * `remove(key)`
+  * `clear()`
+  * `keys()`
+  * `size()`
+  * `toJSON()`
+  * `JSON.stringify(store)`
+
+Upgrading from localStorage and 1.0.x to 1.1.x
+===
+
+1.1.x automatically attempts to upgrade your DOMStorage to use namespaces in backwards-compatible way.
+
+However, you can prevent this behaviour:
+
+    localStorage.getItem('_json-storage-namespaced_', true);
 
 null vs undefined in JSON
 ===
@@ -52,22 +65,22 @@ they're simply to inform you of a few 'gotchas' inherent in JSON / DOMStorage co
 If they do, you're probably doing something wrong in the first place.
 
 
-It is not valid to set `undefined` in JSON. So setting a key to `undefined` will remove it from the db.
+It is not valid to set `undefined` in JSON. So setting a key to `undefined` will remove it from the store.
 
-This means that `db.set('x')` is the same as `db.remove('x')`.
+This means that `store.set('x')` is the same as `store.remove('x')`.
 
 To save `undefined`, use `null` instead.
 
 
 Note that both values that exist as `null` and values that don't exist at all will return `null`.
 
-    db.set('existing-key', null);
-    null === db.get('existing-key');
-    null === db.get('non-existant-key');
+    store.set('existing-key', null);
+    null === store.get('existing-key');
+    null === store.get('non-existant-key');
 
 
 The special case of `null` as `"null"`, aka `"\"null\""`:
 
 `null`, and `"null"` both parse as `null` the "object", instead of one being the string (which would be `"\"null\""`).
 
-Objects containing `null`, however, parse as expected `{ "foo": null, "bar": "null" }` will parse as `foo` being `null` but `bar` being `"null"`, much unlike the value `"null"` being parsed on its own.
+Objects containing `null`, however, parse as expected `{ "foo": null, "bar": "null" }` will parse as `foo` being `null` but `bar` being `"null"`, much unlike the value `"null"` being parsed on its own.

lib/index.js

@@ -1,7 +1,9 @@
 (function () {
   "use strict";
 
-  var db;
+  var Store
+    , delim = ':'
+    ;
 
   function Stringify(obj) {
     var str;
@@ -23,57 +25,122 @@
     return obj;
   }
 
-  function JsonStorage(w3cStorage) {
-    this.db = w3cStorage;
-    this.keysAreDirty = true;
+  function escapeRegExp(str) {
+    return str.replace(/[-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
   }
-  db = JsonStorage;
+
+  function upgradeStorage(jss, w3cs) {
+    var i
+      , key
+      , val
+      , json = {}
+      ;
+
+    if (jss._store.getItem('_json-storage-namespaced_', true)) {
+      return;
+    }
+
+    // we can't modify the db while were reading or
+    // the keys will shift all over the place
+    for (i = 0; i < w3cs.length; i += 1) {
+      key = w3cs.key(i);
+      val = w3cs.getItem(key);
+      json[key] = val;
+    }
+    w3cs.clear();
+
+    Object.keys(json).forEach(function (key) {
+      jss.set(key, json[key]);
+    });
+
+    jss._store.setItem('_json-storage-namespaced_', true);
+  }
+
+  function JsonStorage(w3cStorage, namespace) {
+    // called without new or create
+    // global will be undefined
+    if (!this) {
+      return new JsonStorage(w3cStorage, namespace);
+    }
+
+    // if we didn't always add at least the delimeter
+    // then if a keyname with the delim, it would be more
+    // complicated to figure it out
+    this._namespace = delim;
+    this._namespace += (namespace || 'jss');
+
+    this._store = w3cStorage;
+    this._keysAreDirty = true;
+    if (!this._store.getItem('_json-storage-namespaced_')) {
+      upgradeStorage(this, w3cStorage);
+    }
+  }
+  Store = JsonStorage;
   
-  db.prototype.clear = function () {
-    this.keysAreDirty = true;
-    this.keys().forEach(function (uuid) {
-      this.remove(uuid);
+  Store.prototype.clear = function () {
+    this._keysAreDirty = true;
+    this.keys().forEach(function (key) {
+      this.remove(key);
     }, this);
   };
 
-  db.prototype.remove = function (uuid) {
-    this.keysAreDirty = true;
-    this.db.removeItem(uuid);
+  Store.prototype.remove = function (key) {
+    this._keysAreDirty = true;
+    this._store.removeItem(key + this._namespace);
   };
 
-  db.prototype.get = function (uuid) {
-    return Parse(this.db.getItem(uuid));
+  Store.prototype.get = function (key) {
+    return Parse(this._store.getItem(key + this._namespace));
   };
 
-  db.prototype.set = function (uuid, val) {
-    this.keysAreDirty = true;
-    return this.db.setItem(uuid, Stringify(val));
+  Store.prototype.set = function (key, val) {
+    this._keysAreDirty = true;
+    return this._store.setItem(key + this._namespace, Stringify(val));
   };
 
-  db.prototype.keys = function () {
+  Store.prototype.keys = function () {
     var i
+      , key
+      , delimAt
       ;
 
-    if (!this.keysAreDirty) {
-      return this.__keys.concat([]);
+    if (!this._keysAreDirty) {
+      return this._keys.concat([]);
     }
 
-    this.__keys = [];
-    for (i = 0; i < this.db.length; i += 1) {
-      this.__keys.push(this.db.key(i));
+    this._keys = [];
+    for (i = 0; i < this._store.length; i += 1) {
+      key = this._store.key(i) || '';
+
+      delimAt = key.lastIndexOf(this._namespace);
+      // test if this key belongs to this widget
+      if (-1 !== delimAt) {
+        this._keys.push(key.substr(0, delimAt));
+      }
     }
-    this.keysAreDirty = false;
+    this._keysAreDirty = false;
 
-    return this.__keys.concat([]);
+    return this._keys.concat([]);
   };
 
-  db.prototype.size = function () {
-    return this.db.length;
+  Store.prototype.size = function () {
+    return this._store.length;
   };
 
-  function create(w3cStorage) {
-    return new JsonStorage(w3cStorage);
+  Store.prototype.toJSON = function () {
+    var json = {}
+      ;
+
+    this._keys.forEach(function (key) {
+      json[key] = this.get(key);
+    }, this);
+
+    return json;
+  };
+
+  Store.create = function (w3cStorage, namespace) {
+    return new JsonStorage(w3cStorage, namespace);
   }
 
-  module.exports = create;
+  module.exports = Store;
 }());

lib/package.json

@@ -3,7 +3,7 @@
   "name": "json-storage",
   "description": "A wrapper for storage engines which use the W3C Storage API",
   "keywords": ["ender", "localStorage", "sessionStorage", "globalStorage", "Storage"],
-  "version": "1.0.1",
+  "version": "1.1.0",
   "repository": {
     "type": "git",
     "url": "git://github.com/coolaj86/json-storage-js.git"
@@ -12,6 +12,7 @@
     "node": ">= v0.2.0"
   },
   "main": "index",
+  "browserDependencies": {},
   "dependencies": {},
   "devDependencies": {}
 }

test/test.js

@@ -8,7 +8,7 @@
     ;
 
   assert.equal(null, db.get('x'));
-  assert.deepEqual([], db.keys());
+  assert.deepEqual([], db.keys(), 'found keys in empty db: ' + JSON.stringify(db.keys()));
   db.clear();
   assert.equal(null, db.get('x'));
 
@@ -23,5 +23,9 @@
   db.clear();
   assert.deepEqual([], db.keys());
 
+  db.set('a', 'b');
+  assert.deepEqual(['a'], db.keys());
+  assert.deepEqual({ 'a': 'b' }, db.toJSON());
+
   console.log("Done! All tests pass.");
 }());

test/two-stores-can-have-same-keys.js

@@ -0,0 +1,28 @@
+(function () {
+  "use strict";
+
+  var localStorage = require('localStorage')
+    , jsonStorage = require('../lib/')
+    , assert = require('assert')
+    , store0 = jsonStorage.create(localStorage, '0')
+    , store1 = jsonStorage.create(localStorage, '1')
+    ;
+
+  store0.set('foo', 'bar');
+  store1.set('foo', 'baz');
+
+  assert.strictEqual('bar', store0.get('foo'));
+  assert.strictEqual('baz', store1.get('foo'));
+
+  store0.remove('foo');
+
+  assert.strictEqual(null, store0.get('foo'));
+  assert.strictEqual('baz', store1.get('foo'), 'after removing a value from store1, store0 lost it as well');
+
+  store0.clear();
+
+  assert.strictEqual(null, store0.get('foo'));
+  assert.strictEqual('baz', store1.get('foo'), 'after clearing store0, store1 lost values');
+
+  console.log('[PASS] no assertions failed');
+}());