How to get value of nested constants in angularjs?

Question

I've been trying to get the value of the nested constants inside the angular constants using angular filter. But I can't find an efficient way to get the values. I'm allowed to use lodash "^2.4.1" and i tried using _.pick but still i could only access the root level constants and not the nested ones.

//consider this
angular.module('myApp',[])

.constants('appConstants', {
    CONS1: 'root',
    CONS2: {
          NEST1: 'nested cons1',
          NEST2: 'nested cons2',
    }
)
.filter(getConstants, function  () {
    return function  (input) {
        var value =  appConstants[input];
        if (! value) {
            var keys = input.split('.');
            value =  appConstants;
            angular.forEach(keys, function(key, index) {
                value = value[key];
            });
        }
        return value;
    }
});

//where as
appConstants[CONS1]; //works
appConstants[CONS2.NEST1]; // return undefined
//in lodash
_.pick(appConstants, 'CONS2.NEST1'); // returns empty object

Answer 1

You also have the option of using the Angular $parse function. I think this will work if you provide it with your root constant object as the context parameter.

That might look something like:

$parse(input)(appConstants)