service middleware example to set UNit of measure when action dispatched.

offsetCalculateServiceMiddleware.js

function offsetCalculateServiceMiddleware(offsetCalculateService) {
  return ({ dispatch, getState }) => next => action => {
    if (action.type == 'CALCULATE') {
      myService.setUnitOfMeasurement(getState().getIn(['settings']).toJSON());   
    }
    return next(action);
  }
}