Run JS after rendering a meteor template - meteor

Question

I have a template that looks something like this:
<template name="foo">
<textarea name="text">{{contents}}</textarea>
</template>
I render it with:
Template.foo = function() {
return Foos.find();
}
And I have some event handlers:
Template.foo.events = {
'blur textarea': blurHandler
}
What I want to do is set the rows attribute of the textarea depending on the size of its contents. I realize that I could write a Handlebars helper, but it wouldn't have access to the DOM element being rendered, which would force me to do some unnecessary duplication. What I want, ideally, is for meteor to trigger an event after an element is rendered. Something like:
Template.foo.events = {
'render textarea': sizeTextarea
}
Is this possible?

Answer 1

As of Meteor 0.4.0 it is possible to check if a template has finished rendering, see http://docs.meteor.com/#template_rendered
If I understand your question correctly, you should wrap your textarea resize code inside a Template.foo.onRendered function:
Template.foo.onRendered(function () {
this.attach_textarea();
})

Answer 2

I think the current 'best' way to do this (it's a bit of a hack) is to use Meteor.defer ala Callback after the DOM was updated in Meteor.js.
Geoff is one of the meteor devs, so his word is gospel :)
So in your case, you could do something like:
<textarea id="{{attach_textarea}}">....</textarea>
and
Template.foo.attach_textarea = function() {
if (!this.uuid) this.uuid = Meteor.uuid();
Meteor.defer(function() {
$('#' + this.uuid).whatever();
});
return this.uuid;
}
EDIT
Note, that as 0.4.0, you can do this in a much ad-hoc way (as pointed out by Sander):
Template.foo.rendered = function() {
$(this.find('textarea')).whatever();
}

Answer 3

Since about June 2014, the correct way to do this has been to set a callback using Template.myTemplate.onRendered() .

Answer 4

Yeah I think so - not sure if it's "the right way", but this works for me:
In your app JS, the client section will run whatever javascript there on the client. For example:
if (Meteor.is_client) {
$(function() {
$('textarea').attr('rows' , 12) // or whatever you need to do
})
...
Note the example here uses JQuery, in which case you need to provide this to the client (I think :-). In my case:
I created a /client dir, and added jquery.js file under this.
Hope this helps.