gistfile1.js

import { compose } from 'react-komposer'

function RV(component, states) {

  const localStates = {}
  const localValues = {}

  for (let state in states) {
    localStates[state] = new ReactiveVar(states[state])
  }

  const track = (props, onData, env) => {
    for (let state in localStates) {
      localValues[state] = localStates[state].get()
    }

    onData(null, { localValues, localStates, props, env })
  }

  const Component = compose(composeWithTracker(track))(component)

  return {
    localStates,
    localValues,
    component: <Component />,
  }

}

function composeWithTracker(reactiveMapper) {
  return (props, onData, env) => {
    let trackerCleanup = null;
    const handler = Tracker.nonreactive(() => {
      return Tracker.autorun(() => {
      	// assign the custom clean-up function.
        trackerCleanup = reactiveMapper(props, onData, env);
      });
    });

    return () => {
      if (typeof trackerCleanup === 'function') trackerCleanup();
      return handler.stop();
    };
  };
}