meteorhacks:aggregate error - meteor

Question

I'm trying to publish some data using meteorhacks:aggregate:
Meteor.publish('alleNascholingen',function() {
var self = this;
var nascholingenOverzicht = nascholingenCollectie.aggregate([
//{$match: {creatorId: this.userId}},
//{$project: {naam: 1, familienaam:1, nascholingen:1}},
{ $unwind : "$nascholingen" },
{ $sort: {
"nascholingen.inschrijfMoment": -1
}}
]);
_.each(nascholingenOverzicht, function(parent){
_.each(parent, function(child){
self.added('selectie', child._id, child);
});
});
self.ready()
});
I have two collections, one to store the aggregated data:
nascholingenCollectie = new Mongo.Collection('nascholingen');
nascholingenSelectie = new Mongo.Collection('selectie');
On my template I subscribe to the data:
Template.nascholingBeheer.onCreated(function() {
let self = Template.instance();
self.subscribe('alleNascholingen', function () {
setTimeout(function () {
}, 300)
})
})
});
I'm getting the following error in my chrome console:
collection.js:173 Uncaught Error: Expected to find a document to change
at Object.update (http://localhost:3000/packages/mongo.js?hash=c4281c0ff989ebee020f59f5a7b0735053cea5f7:246:29)
at Object.store.(anonymous function) [as update] (http://localhost:3000/packages/ddp-client.js?hash=bc32a166cd269e06a394f9418e0024d805bab379:3613:48)
at http://localhost:3000/packages/ddp-client.js?hash=bc32a166cd269e06a394f9418e0024d805bab379:4441:19
at Array.forEach (native)
at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?hash=cde485f60699ff9aced3305f70189e39c665183c:149:11)
at http://localhost:3000/packages/ddp-client.js?hash=bc32a166cd269e06a394f9418e0024d805bab379:4440:13
at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?hash=cde485f60699ff9aced3305f70189e39c665183c:157:22)
at Connection._performWrites (http://localhost:3000/packages/ddp-client.js?hash=bc32a166cd269e06a394f9418e0024d805bab379:4437:9)
at Connection._flushBufferedWrites (http://localhost:3000/packages/ddp-client.js?hash=bc32a166cd269e06a394f9418e0024d805bab379:4423:10)
at Connection._livedata_data (http://localhost:3000/packages/ddp-client.js?hash=bc32a166cd269e06a394f9418e0024d805bab379:4391:12)
What am I doing wrong here?

Answer 1

You can not use aggregation in Meteor publication, only in Meteor method. To work around that you could consider using this package (disclaimer: I am the author).

Answer 2

My bad...I found my error:
_.each(nascholingenOverzicht, function(parent){
_.each(parent, function(child){
self.added('selectie', child._id, child);
});
});
should be:
_.each(nascholingenOverzicht, function(parent){
self.added('selectie', parent._id, parent);
});