Question

var User = Parse.User.extend({
    // instance members
}, {
    // types
    TYPE_TRAINER : 1,
    TYPE_ATHLETE : 2,
    types: {
        TYPE_TRAINER : 'Trainer',
        TYPE_ATHLETE : 'Athlete'
    }
});

I want to have TYPE_TRAINER and TYPE_ATHLETE maintain the values of 1 and 2 as defined prior to the types object so that I can use the types object in a template.

If you don’t know about Parse, Parse.User is an extension of Backbone.Model.

Thanks!

Answer 1

What you’re asking is not directly possible in JavaScript object literals. Object literals are always a literal value on the left hand / key side.

The closest you could get is to use the TYPE_TRAINER and TYPE_ATHLETE keys as variables to assign values via the square bracket syntax for accessing object key/value pairs:

var a = 1;
var b = 2;

var obj = {};
obj[a] = "a";
obj[b] = "b";

This will result in the obj object looking like this:

{
  1: "a",
  2: "b"
}

So you could do something like this, to get what you want in your code:

var userMethods = {
    // types
    TYPE_TRAINER : 1,
    TYPE_ATHLETE : 2
};

userMethods[userMethods.TYPE_TRAINER] = 'Trainer';
userMethods[userMethods.TYPE_ATHLETE] = 'Athlete';

var User = Parse.User.extend({
    // instance members
}, userMethods);

It’s more code than you probably want, but it’s the only way to achieve what you want because of the object literal syntax.