Rendering new div created dynamically with Meteor - node.js

Question

I have a the classic "Thread->Posts" model.
In the application, I have a left sidebar with the "Thread" collections. When the user click in a Thread, I want to create another div with the Thread->Posts elements.
Is there any way to do this, conservating the reactivity?
For now, I've got this:
// In the client
Template.threadlist.events({
'click tr': function(event){
Session.set("selectedThread",this);
$("#posts").html( Meteor.render(Template["datathread"]) );
}
})
[...]
Template.datathread.events({
'click input.add-post' : function(event){
var t = Session.get("selectedThread");
Meteor.call("addPost", {"thread":t,"text":"foo","user":"var"},callback})
}
})
[...]
// In the server
addPost: function(param){
var id = Threads.update(param.thread,{ $addToSet: {"posts": {"text":param.text, "user": param.user}}});
return id;
}
The template with the posts is something like this:
<template name="datathread">
{{#each thread.posts}}
{{user}} says: {{text}}
<br />
{{/each}}
</template>
(The "user" and "text" propertis are from the "thread.posts" elements)
With this code, I only get the new values refreshing (F5) the webpage (or executing the 'click tr'event). What I'm doing wrong?
Thank you!
== Edit ==
Ok... Now, with the recomendation of Chistian Fritz, my code its something like this:
// In the client
Template.datathread.thread = function(){
return Session.get("selectedThread");
}
[...]
Template.threadlist.events({
'click tr': function(event){
Session.set("selectedThread",this);
}
});
//In the html
<div class="span5" id="threads">
{{> datathread}}
</div>
<template name="datathread">
{{#if thread}}
<hr />
{{#each thread.posts}}
{{user}} says: {{text}}
<br />
{{/each}}
{{/if}}
</template>
The changes are great (it's so simple!), but the reactivity still doesn't work :(....

Answer 1

The problem is that you are using jQuery to fill your DOM:
$("#posts").html( Meteor.render(Template["datathread"]) );
This breaks the reactivity chain.
You are only showing part of your code, so I can't give you the full solution, but it seems that the datathread template is already using the selectedThread session variable -- which is good. Hence, it might be as easy as using {{> datathread}} in place of the #posts element in your HTML.
EDIT:
One thing that you need to change is the scope you are assuming datathread: it's already the thread itself, if I understand correctly:
<template name="datathread">
<hr />
{{#each posts}}
{{user}} says: {{text}}
<br />
{{/each}}
</template>
Also, the this in the threadlist event handler most certainly won't be the thread. I don't know the data of the tr in the threadlist (can you show that code?), but you will most probably do something like the following:
Session.set("selectedThread", this.id);
And for datathread:
Template.datathread.thread = function(){
return Threads.find({_id: Session.get("selectedThread")});
}
or similar.