version-storage

localStorage like, fileSystem/localStorage based storage with upgrade.

Usage

var upgrade = function(storage) {
    var oldVersion = storage.version;
    if(oldVersion < 1) {
        // Version 1 is the first version of the database.
        storage.setItem('hello', '[1, 2, 3]');
    }
    if(oldVersion < 2) {
        // Version 2 changes the data structure of `hello`
        var hello = storage.getItem('hello');
        // do some remaping
        storage.setItem('hello', newhello);
    }
    if(oldVersion < 3) {
        // Version 3 changes the name of `hello`
        var hello = storage.getItem('hello');
        storage.removeItem('hello');
        storage.setItem('world', hello);
    }
    storage.setVersion(3);
};

var storage = new VersionStorage('kizz/file', upgrade);
var sth = storage.getItem('sth');

// for nodejs
var FsStroage = require('fs-storage');
var fsStorage = new Storage('./storage/');
var storage = new VersionStorage('kizz/file', {storage: fsStorage}, upgrade);
var sth = storage.getItem('sth');