[Vuejs]-Radiobutton-like behaving Vue.js components

Take a look at two-way binding: http://vuejs.org/guide/components.html#Prop_Binding_Types

This allows you to sync a property’s value in both directions, meaning the parent or the child has access to change the variable. Then you can watch for changes on the parent and update accordingly.

I think a better option would be to create a RadioSet component, which then would house a number of radio buttons. This would eliminate your concern about a parent having to have the activate() method. You could simply pass in an object with a series of id and values that could be used to generate the buttons.