Rails-like migrations for Titanium

titanium_migrations.js

/*
  Model methods below requires Joli.js: https://github.com/xavierlacot/joli.js
  Requires a tables named 'migrations' with columns id & version

  Database migrations
  Each migration is attached to a timestamp
  When the migration is run, a record is added to the migrations table so it isn't run again
  The rollback function takes a string date and rolls back all migrations since that date and deletes the migration record

  Usage:
  Migrations.migrate();
  Migrations.rollback('2011/03/08');
*/
Migrations = (function() {
  var c = {};
  c.versions = {
    1299703938917: {
      down: function() {
        var record = models.settings.findOneBy('name', 'testing_migrations');
        models.settings.deleteRecords(record.id);
      },
      up: function() {
        var record = {
          name: 'testing_migrations',
          value: 1
        };
        models.settings.newRecord(record).save();
      }
    }
  };
  c.migrate = function() {
    for(var i in c.versions) {
      if(c.versions[i]) {
        migration = models.migrations.findOneBy('version', i);
        if(!migration) {
          c.versions[i].up();
          models.migrations.newRecord({version: i}).save();
        }
      }
    }
  };
  c.rollback = function(the_date) {
    var timestamp = new Date(the_date).getTime();
    for(var i in c.versions) {
      if(c.versions[i] && i >= timestamp) {
        migration = models.migrations.findOneBy('version', i);
        if(migration) {
          c.versions[i].down();
          models.migrations.deleteRecords(migration.id);
        }
      }
    }
  };
  return c;
})();