subscribable wrapper for falcor models, for reactive components

falcor-subscribable-model.js

const falcor = require('falcor');
const Rx = require('rxjs');

//FalcorSubscribableModel
module.exports = function(modelOptions) {
  modelOptions = modelOptions || {};

  const self = {};
  const modelSubject = new Rx.BehaviorSubject();

  modelOptions.onChange = function() {
    modelSubject.next(self.model);
  };

  self.model = new falcor.Model(modelOptions).batch(30);

  self.subscribe = function(path, ...subscriptionArgs) {
    const stream = modelSubject.flatMap(() => {
      return Rx.Observable.fromPromise(self.model.get(path));
    }).filter((response) => {
      return response != null;
    });
    const subscription = stream.subscribe(...subscriptionArgs);
    self.get(path);
    return subscription;
  };

  self.call = function(...args) {
    return self.model.call(...args).then((response) => {
      //hack: falcor.Model operations don't do anything unless a "then" is specified
      return response;
    });
  };

  self.set = function(...args) {
    return self.model.set(...args).then((response) => {
      //hack: falcor.Model operations don't do anything unless a "then" is specified
      return response;
    });
  };

  self.get = function(...args) {
    return self.model.get(...args).then((response) => {
      //hack: falcor.Model operations don't do anything unless a "then" is specified
      return response;
    });
  };

  Object.freeze(self);
  return self;
};

//usage - would like to reduce boilerplate
/*
const blogModel = require('./blog-model');
const BlogPost = React.createClass({
  propTypes: {
    postId: React.PropTypes.number.isRequired,
  }
  
  componentWillMount: function() {
    this.setupSubscription(this.props.postId);
  },
  
  componentWillReceiveProps: function(newProps) {
    this.setupSubscription(newProps.postId)
  },
  
  componentWillUnmount: function() {
    this.cleanupSubscription();
  },
  
  setupSubscription: function(postId) {
    this.cleanupSubscription();
    this.subscription = blogModel.subscribe([
      'postsById', postId, [
        'title',
        'body',
        'author',
      ],
    ], (response) => {
      this.setState({
        title: response.json.postsById[postId].title,
        body: response.json.postsById[postId].body,
        author: response.json.postsById[postId].author,
      });
    });
  },
  
  cleanupSubscription: function() {
    if (this.subscription) {
      this.subscription.unsubscribe();
    }
  }
  
  render: function() {
    return (
      <article>
        <header>{this.state.title}</header>
        <p>{this.state.body}</p>
        <p>by {this.state.author}</p>
      </article>
    );
  },
});
*/