Socket IO not syncing "thing" in default app

[EliKrumholz]

• I understand that GitHub issues are not for tech support, but for questions specific to this generator, bug reports, and feature requests.

Item	Version
generator-angular-fullstack	4.1.2
Node	6.9.5
npm	3.9.5
Operating System	OS X 10 and Heroku

Item	Answer
Transpiler	Babel
Markup	HTML
CSS	SCSS
Router	ui-router
Client Tests	Mocha
DB	MongoDB
Auth	Y
SocketIO	Y

"Things" in the main view are not syncing automatically when created or deleted, a full page refresh is required to see the updates. I observed this behavior on both OSX 10.12 and on heroku using default settings for the generator at v4.1.2. Just a default build of the generator deployed to heroku should replicate this bug as far as I can tell.

I am not seeing any errors on either the client side or the server side, any suggestions on where to start tracking down this bug?

[ernistkg]

Problem

I have researched this issue and found reason why this doesn't work.

In thing.events.js file
./server/api/thing/thing.events.js

// Register the event emitter to the model events
for(var e in events) {
  let event = events[e];
  Thing.schema.post(e, emitEvent(event));
}

As you can see inside for loop remove and save events are applied to Thing Schema thorough POST HOOKS . And this hooks never called. I think this happens because we are applying HOOKS to Shema after Thing model is already created in model file:

export default mongoose.model('Thing', ThingSchema);

Solution

Problem solved when I applied hooks before model created:
In thing.model.js file
./server/api/thing/thing.model.js

'use strict';

import mongoose from 'mongoose';

var ThingSchema = new mongoose.Schema({
  name: String,
  info: String,
  active: Boolean
});

require('./thing.events').applyHooks(ThingSchema);

export default mongoose.model('Thing', ThingSchema);

And thing.events.js was modified to export applyHook function which will apply schema hooks before mongoose model is created.
./server/api/thing/thing.events.js

/**
 * Thing model events
 */

'use strict';

import {EventEmitter} from 'events';
var ThingEvents = new EventEmitter();

// Set max event listeners (0 == unlimited)
ThingEvents.setMaxListeners(0);

// Model events
var events = {
  save: 'save',
  remove: 'remove'
};

function emitEvent(event) {
  return function(doc) {
    ThingEvents.emit(`${event}:${doc._id}`, doc);
    ThingEvents.emit(event, doc);
  };
}

export function applyHooks(schema) {
// Register the event emitter to the model events
  for(var e in events) {
    let event = events[e];
    schema.post(e, emitEvent(event));
  }
}

export default ThingEvents;

[ernistkg]

I might be wrong in reasons but this solution works.

[EliKrumholz]

Nice work, Ernisto, thanks! I was able to replicate your solution and it fixes the issue on my heroku deployment.

I think you're correct about Thing.schema.post not working properly in ./server/api/thing/thing.events.js but I actually think this is on the end of Mongoose, rolling back the version to "mongoose": "~4.7.9" in package.json seems to fix this error too, which also means it's probably related to #2479, so rolling back mongoose for now and opening an issue with mongoose is probably the best solution.

[ernistkg]

Thank you!

I haven't tried older versions. I thought something was broken in angular-fullstack after refactor maybe or something else.

[Awk34]

Closing as duplicate of #2479