Angularjs Form/Field validation using JavaScript function without directives

Question

Is there a way to validate a field in angular without using a directive? For example: I want to make following validation on an input field.

Answer 1

Well you can try to create a func

Value must be an even number

$scope.isEven=function(data) {
    if(data) {
        return data%2===0
    }
    return true;
}

The method can either be defined on the current controller scope or on $rootScope.

Not a very angular way, as directives would be better but i think it would work.