How do I sort a collection that has already been rendered? Like AngularJS's orderBy directive

Question

How do I sort or manipulate a data collection that has already rendered?

I have a template helper registered that is defined more or less like:

Template.home.helpers({
    posts: function() {
          return Posts.find({}, { sort: { createdAt: -1 } });
    }
});

Which sorts the posts by the most recent ones appearing first. But I want to implement a functionality that reverses this; displaying the oldest posts first.

What is the MeteorJS way of doing it? Any ideas/help is much appreciated.

Answer 1

I would do it using a session variable, like so:

First, set the default to display in descending order:

Template.home.onRendered({
    Session.set("displayOrder", -1);
});

Then, define a link somewhere in your html to allow the user to change the order:

<a href="#" id="sort">Change sort order</a>

Then define an event to toggle the sort order on click

Template.home.events({
    'click #sort' : function () {
        var order = Session.get("displayOrder");
        var newOrder = -1 * order;
        Session.set("displayOrder", newOrder);
    }
});

And then change your helper, like so:

Template.home.helpers({
    posts: function() {
      var displayOrder = Session.get("displayOrder")
      return Posts.find({}, { sort: { createdAt: displayOrder } });
    }
 });