Manager interfering with ReactMeteorData

[tomitrescak]

Hi, first thanks for this optimisation item without which I cannot imagine my applications to be. I have found a possible bug in the implementation, when subscription manager is interfering with "ReactMeteorData" mixin. I am attaching a minimal repro application.

The problem is, that if you use a component with subscriptions inside another component with subscriptions, it is invalidating the parent subscriptions, making them run twice or more. Example:

I have following components and only parent has subscriptions:

<Parent>
<Child>
</Parent>

If I put following line inside paren's "render" method console.log("With: " + this.data.posts) where data is fed with following method:

getMeteorData() {
    this.data = { }
    var handle = subs.subscribe("posts");
    if (handle.ready()) {
      this.data = {
        posts: Posts.find().fetch()
      }
    }
    return this.data;
  },

The output is following as expected:

With: undefined
With: undefined
With: [object Object],[object Object],[object Object]

Now I add another subscription inside child component as following:

  getMeteorData() {
    this.data = { }
    var handle = subs.subscribe("user", this.props.post.uid); // Replace with Meteor.subscribe and all is good
    if (handle.ready()) {
      this.data = {
        user: Usrs.findOne({uid: this.props.post.uid})
      }
    }

    return this.data;
  }

Output becomes:

With: undefined
With: undefined
With: [object Object],[object Object],[object Object]
With: undefined
With: [object Object],[object Object],[object Object]

Somewhere there, the subscription invalidated meteor data and it ran again creating havoc in the application. Please note, that when I replace subs.subscribe with Meteor.subscribe all is running as expected and data is not invalidated.

Example minimal app is here 6Kb.

[arunoda]

Yes. I can understand the issue. I think it's hard to mitigate this unless, you create two instances of subsManagers to each component.

I've added some notes here: https://goo.gl/9PeI1Q

[tomitrescak]

Thanks! Just a question regarding performance .. .will that affect subsmanager performance if I will be creating a new instance of subs manager per each subscription? Will that interfere with its functionality ?
Thanks.

[arunoda]

Nope. It create caches separately.

On Fri, Sep 18, 2015 at 7:25 AM Tomas Trescak [email protected]
wrote:

Thanks! Just a question regarding performance .. .will that affect
subsmanager performance if I will be creating a new instance of subs
manager per each subscription? Will that interfere with its functionality ?
Thanks.

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