how to build a reactive web service backed collection in meteor

Question

I am very new to Meteor and began writing a meteor app with connection to a non-web based server. As all data should be routed through this server, it has a REST interface for fetching and manipulating the relevant Objects.

Now I am stuck at how to build a collection for this web service. I tried to use the approach shown in here: https://medium.com/meteor-js/how-to-connect-meteor-js-to-an-external-api-93c0d856433b

This works for fetching the current results. But when I add/delete/update records, there is no update at all.

On the server side, I am publishing like this:

Meteor.publish('someThings', function() {
    var self = this;

    try {
        var records = HTTP.get("http://localhost:6789/things/", {auth: "user:passwd"});

        _.each(records.data, function(record) {

            var thing = {
                uuid: record.uuid,
                title: record.title,
            };

            self.added('things', thing.uuid, thing);
        });

        self.ready();
    } catch (error) {
        console.log(error);
    }
  }
);

then globally, I have a collection:

SomeThings = new Meteor.Collection("things");

and I use it in the React component like this:

SomeThings = new Meteor.Collection("things");

getMeteorData() {
    return {
      things: SomeThings.find({}).fetch()
    };
  },

Somewhere in the client, I added this additionally (as in the howto):

  Tracker.autorun(function() {
      Meteor.subscribe('someThings');
  });

Finally on the server side I have some functions which do the manipulation, once via the REST interface, once on the collection (example: insertion):

addThing: function(title) {
  result = Meteor.http.post("http://localhost:6789/things/",
    {auth: "user:passwd", params: {title:title}});
  SomeThings.insert(result.data);
}

I read something about the added() function and similar functions in Meteor.publish() but could not understand how/if I could use this to enable "instant" synchronization between the server and client or the collection and the ui elements.

So basically I would like to know how to build a reactive collection which is not based on a database but on a REST interface instead.

Could someone give me some advice/hints on how I can achieve this?

Answer 1

Publications do not automatically re-run HTTP requests. You will need to somehow detect when the data in the API has changed (the simple way would be to run the query on a Meteor.setInterval) and call this.updated and this.removed to notify the client of changes.