Model.md

nbd/Model

extend nbd/Class mixin nbd/trait/pubsub

Events:

• Name of any property of the model : (currentValue, previousValue)

The data-wrapping class of nbd.js. It is meant to be instanciated with the data object you want to manage. The primary purpose of having the Model class manage a data object is to have a consistent interface by which the data is accessed and modified, and to provide change notification.

Async Diff Check:

When a Model instance has its data members changed according to the nbd/util/diff module, it triggers an event with the same name as the key of the member that has changed, with the value as the argument to the event. This change detection happens off the current callstack, so as not to put overhead on data manipulation itself.

require(['nbd/Model'], function(Model) {
  var car = new Model({
    rims: 'plain'
  });

  car.on('rims', function(is, was) {
    console.log("New "+is+" rims");
  });
  car.data().rims = "kickin'"; // logs: New kickin' rims
});

constructor([id,] data)

The Model constructor expects the data to be managed. The data is internally stored as a reference to data, so modifying the original data object will change it in the Model instance.

In addition to the data, Model can also be created with an id for the common use case of a piece of data being tied to a server id. In that case, there exists a .id() method that returns the id it was initialized with. This id can be a number or a string. A numeric string will automatically be converted into a number.

returns Model A new instance of Model

.data()

The accessor method for retrieving the entire data object.

It is one of the two interface accessor methods. Calling it will trigger an async diff check if data has changed – firing off events of the changed keys. This is so that you can retrieve the object once, make manipulations to it, and then have the Model automatically detect all the changes.

returns Object The data object that the instance of Model is managing

.get(key)

The accessor method for retrieving only one value from the data object.

It is the other accessor method. Calling it will not trigger an async diff check, since it is intended only to retrieve a value.

returns anything The value associated with the specified key

.set(key, value)

.set(data)

The setter function. It takes two forms, either the key-value pair as two arguments, or an object of keys and values. Calling this method will trigger an async diff check.

returns this

.destroy()

The Model destructor is just a convenience function since in JavaScript, destructors are not automatically called when the object is actually destroyed. Model's destructor simply unbinds all events that had been bound to that instance.