Get a Backbone Model instance's model/class name

Question

Given an instance of Backbone model, how can I know the "class" (so to speak) of this instance ?

For instance:

class Car extends Backbone.Model

mycar = new Car()

And what I need is:

mycar.modelName # => 'Car'

Solution 1

It's problematic in general, I think. I was going to suggest some of the options mentioned here ( How do I get the name of an object's type in JavaScript? ) but I was having issues with the first option. You could always extend all your models to have a function that returned a "name" for the model, but I can understand why you might find that less than satisfactory.

Solution 2

I tried Mitch's suggestion but in Chrome, model.constructor.name is always "" for me.

I chose instead to use a convention. I now create a class property using the second param of extend that works as follows:

directory.models.SomeModel = Backbone.Model.extend({ 
    //  usual model instance stuff
}, {
    modelType: "SomeModel"   // class property
});

I found that I can always get what I want like this:

var mt = model.constructor.modelType;

Solution 3

As of writing you can get a model's class name by doing the following:

model.constructor.name

This works for me in the Chrome browser.

Comments

[JayC]

You need to be more specific. A model could have multiple views. The view has the .el reference which AFAIK should be enough, if you are considering views. But that may not be what you're asking about.

[JayC]

Ah, nevermind. You're talking programmatically.

[websymphony]

Why do you need the classname? To create a new model of same type or to access a class level function or something else? Its interesting question.

[Blacksad]

@websymphony I need it because I have a mix-in which at a certain stage requires the class name.

[rxgx]

There won't be a notion of class in JavaScript for another 5 years (ECMAScript 6+?). The object creation syntax of CoffeeScript causes much confusion to those just getting familiar with the language. Using Object.create and an extend method may be an easier way to implement inheritance via mixins.

[fguillen]

I agree, either you solve it manually as @JayC suggests or you are talking about a very old generic JS concern still not resolved.

[dB.]

Note that this is not going to work if you have a minifier like Jammit, the constructor will change after packaging.