Ractive.js: Resolve mapped keypaths from child instances to its correct keypath in the calling instance (if they originate from that instance or one of its parents).

keypath_resolve.js

function keypath_resolve(keypath, instance, caller){
  return (function _resolve(keypath, instance, caller){
      var keypathArray, mapped;
 
      // if instance is the caller, return the current keypath
      if(instance === caller) {
          return keypath;
      }
 
      // split the keypath, look for the first key in viewmodel mappings
      keypathArray = keypath.split('.');
      mapped = instance.viewmodel.mappings[keypathArray[0]];
 
      // if nothing is mapped for the first key, this is as far as we get.. (and we haven't reached the caller, thus returning false)
      if(!mapped) {
          return false;
      }
 
      // replace or first key with the mapped keypath, and make a new keypath
      keypathArray[0] = mapped.keypath.str;
      keypath = keypathArray.join('.');
 
      // as long as the first key is mapped, there is a parent
      return _resolve(keypath, instance.parent, caller)
 
  })(keypath, instance, caller);
}

// example usage:
instance.on('*.bubbled',function(event){
  var keypath = resolve_keypath(event.keypath, event.ractive, this);
  this.set(keypath,'foo');
});