Access helpers from onCreated in Meteor

Question

I have:

Template.myTemplate.helpers({
  reactiveVar: new ReactiveVar
});

How can I access reactiveVar from onCreated to set it up?

Template.restaurantEdit.onCreated(function() {
  // Access helpers.reactiveVar from here to set up
  // My goal is to set up data to reactiveVar, ex:
  helpers.reactiveVar = this.data.someData;
});

I found there is protected __helpers: this.view.template.__helpers

But is there any Meteor 's nice way to access helpers? or which is the Meteor's way to set up reactiveVar from loaded data

Answer 1

You basically don't access helpers in Meteor directly. If you want to use scoped reactivity with ReactiveVar, you should do it this way:

Template.restaurantEdit.onCreated(function() {
  //define all your reactive variables here
  this.reactiveVar = new ReactiveVar('default value');
});

Template.restaurantEdit.helpers({
  reactiveVar: function() {
    //access reactiveVar template variable from onCreated() hook
    return Template.instance().reactiveVar.get();
  }
});

Template.restaurantEdit.events({
  'click yourselector': function(evt, template) {
    template.reactiveVar.set('new value');
  }
});

Read more about scoped reactivity here: https://dweldon.silvrback.com/scoped-reactivity

Answer 2

You should set up the reactive variable in your onCreated() block and then access it via a helper , not vice-versa.

Template.restaurantEdit.onCreated(function(){
  this.foo = new ReactiveVar;
});

Template.restaurantEdit.helpers({
  foo: function(){
    return Template.instance().foo.get();
  }
});

The helper will update whenever your ReactiveVar changes.