Support init or setup returning something other than new instance

[ilyavf]

Allow to return special new Construct.ReturnValue( value ) from setup method, so that this value will be returned as the result of new Construct( ... ):

var Student = function(){};
var Person = Construct.extend({
    setup: function(params){
        if (params.isStudent){
            return new Construct.ReturnValue( new Student(params) );
        } else {
            return [params];
        }
    }
});
console.log( new Person({isStudent: true}) instance of Student );
// => true

[ilyavf]

Fixed acc to feedback. Need to add docs...

[justinbmeyer]

Could probably use Object.assign here.

[ilyavf]

Fixed.

[justinbmeyer]

Might use Object.assign here too.

[ilyavf]

Fixed.

[justinbmeyer]

This should almost certainly be done in setup. init is usually left for people inheriting from Item to use for their particular Item type.

[ilyavf]

Fixed.

[justinbmeyer]

Too much detail for a description. It shouldn't care at all about the value property. Maybe something like:

Use to overwrite the return value of new Constructor(...).

[justinbmeyer]

The signature should talk about how this works. Also, the example code below should be put in the signature.

[ilyavf]

Fixed.

[justinbmeyer]

I think the value MUST be an Object type. If someone tries to return a number, it won't work.

[justinbmeyer]

Also, indent 2 spaces @param and other nested @ tags.

[ilyavf]

Fixed.

[justinbmeyer]

Change:

If [can-construct.ReturnValue] is returned then the value that passed to it
will be used as a value for a new instance.

To something more like:

If a [can-construct.ReturnValue] instance is returned, the ReturnValue instance's
value will be returned as the result of calling new Constructor().

[ilyavf]

Fixed.