Object equality comparison for input[radio] with ng-model and ng-value

Answer 1

OK, so after further review, I decided to go with a more "mix-in" approach, just replacing the ng-model directive with my own custom directive, in essence. This is very similar to the approach I used for making a "checkbox list" directive based on this answer: https://stackoverflow.com/a/14519881/561604.

.directive('radioOptions', function() {
    // Apply this directive as an attribute to multiple radio inputs. The value of the attribute
    // should be the scope variable/expression which contains the available options for the
    // radio list. Typically, this will be the collection variable in an ng-repeat directive
    // that templates the individual radio inputs which have radio-options applied. In addition,
    // instead of the normal ng-model, use a selected-option attribute set to the same expression.
    // For example, you might use radio-options like this:
    // 
    //