Do routes with same controller subscribe to server n times or just once?

Question

I have a tabs with four tab, each has a route with same controller.

All four tabs share the same data, menu, but use different part of the data.

Every time I click a tab, will it do a subscribe to the server?

For example, the first time I click tab1, it will contact server and get the data menu, then I click tab2, will it contact server again to fetch data menu even I have already gotten the data?

If so, how can I avoid this? Maybe I should redesign the code, is there any good ideas?

MenuController = RouteController.extend({
  layoutTemplate: 'menuLayout',

  waitOn: function () { return Meteor.subscribe('menu', this.params._id); },

  data: function () { return Menu.findOne({_id: this.params._id}) },

});


this.route('/menu/tab1', {
  name: 'menu.tab1',
  template: 'MenuTab1',
  controller: MenuController,
});
this.route('/menu/tab2', {
  name: 'menu.tab2',
  template: 'MenuTab2',
  controller: MenuController,
});
this.route('/menu/tab3', {
  name: 'menu.tab3',
  template: 'MenuTab3',
  controller: MenuController,
});
this.route('/menu/tab4', {
  name: 'menu.tab4',
  template: 'MenuTab4',
  controller: MenuController,
});

Answer 1

This has changed somewhat as IR has matured. I believe in the current implementation, if you change between routes which make the same subscription with the same parameters, the subscription will not be stopped and started again. In other words, switching between tabs should not start and stop the subscription (assuming this.params._id remains constant).

You can prove (or disprove) this by adding a console.log('here') to the first line of your menu publisher. When you switch tabs, check the command-line console. If 'here' is printed only once, you have the desired outcome.

Regardless of the outcome, subs-manager is the generally accepted solution for caching subscriptions between routes.