Gist accompanies a blog post which is a follow-up to my follow-up write-up of my 6/19/2013 BurlingtonJS talk.

protocols-redux.js

// Where `reviews` is a list of Review objects...

// shared by client and server: simple naive validator:
var ValidationProtocol = (function() {
  var validationRules = {
    // properties to validate + functions...
  };
  
  return {
    // using our imagination here:
    isValid: function() {
      var valid = true;
    
      for (var p in this) {
        if (validationRules[p]) {
          valid = validationRules[p](this[p]);
        }
        if (!valid) break;
      }
    
      return valid;
    }
  };
}());

// on the server
var ServerPersistenceProtocol = {
  // assuming a mongodb connection through Mongoose or similar:
  update: function() {
    if (this.isValid()) {
      this.save(function(err) {
        if (err) console.error('[mongo] ERROR: %s', err.message);
        else console.log('[mongo] OK!');
      });
    }
    
    return this;
  }
};

_.extend(Review.prototype,
    ServerPersistenceProtocol,
    ValidationProtocol);

_.each(reviews, function(r) {
  r.update();
});

// on the client
var ClientPersistenceProtocol = {
  // using our imagination here:
  update: function() {
    var _updates = this.getUpdates();

    if (!_.isEmpty(_updates) && this.isValid()) {
      $.ajax('/reviews', { type: 'PUT', data: _updates });
    }

    return this;
  }
};

_.extend(Review.prototype,
    ClientPersistenceProtocol,
    ValidationProtocol);

_.each(reviews, function(r) {
  r.update();
});

The above gist accompanies this blog post: http://blog.founddrama.net/2013/06/on-protocols/

Also: in the gist:

• _ is for Underscore
• $ is for jQuery

(Just so we're all clear about our assumptions.)