How Do I Run Client-side Code After A New Collection Item Has Been Added To A Meteor View?

In my template, I call a server-side method to add an item to a collection. This collection is displayed on the page. Once the new item is rendered, I want to focus it for the user

Solution 1:

Your original code is really close - you just need to put the focus logic into a reactive context so it will run again with the session variable changes. The shortest path to success is to use a template autorun:

Template.postsAdmin.onRendered(function() {
  this.autorun(function() {
    var newPostId = Session.get('newPostId');
    if (newPostId) {
      var $newPostCell = $('#' + newPostId);
      return $newPostCell.find('.post').focus();
    }
  });
});

---

However, one problem you may run into is that you'll have a race condition where the new post is added after the autorun fires. A hacky solution is to add a timeout to the above. An improved solution is to add something like your original code to the onRendered callback of the newly added post sub-template:

Template.post.onRendered(function() {
  var newPostId = Session.get('newPostId');
  if (newPostId === this.data._id) {
    // add code here to focus this template instance
  }
});

Solution 2:

One option may be observeChanges? Can you try this?

in the rendered function do following

Template.postsAdmin.rendered = function(){

   var query = Posts.find({}); //your query
   var handle = query.observeChanges({
       added: function (id, user) {
          //code to set focus???
       }
   });
}

This code runs whenever there is a new item addeded to minimongo which matches your query.

Make sure to show the template after you load the data.

docs link http://docs.meteor.com/#/full/observe_changes