Adding ajax to Rails 3 form_for - ruby-on-rails-3

Question

I'm learning to program and got a form running in my Rails 3 app. Now I'm attempting to add ajax to the form so the page doesn't reload after submitting.
I've followed the numerous tutorials but can't quite seem to figure out how to bring it together. The form adds new Objects to the Profile through the following model:
class Profile < ActiveRecord::Base
has_many :objects
end
class Object < ActiveRecord::Base
belongs_to :profile
end
My form in views/profiles/_object_form.html.erb:
<%= form_for(#object, :remote => true) do |f| %>
<% end %>
Where the form and its created objects are rendered in my views/profiles/_about.html.erb:
<div id="newObjects">
<%= render :partial => 'object_form' %>
</div>
<div id="objectList">
<%= render :partial => 'object', :collection => #profile.objects, :locals => {:object_count => #profile.objects.length) %>
</div>
In my objects_controller.rb I have the following create action:
def create
#object = Object.new(params[:object].merge(:author_id => current_user.id))
respond_to do |format|
if #object.save!
format.html {redirect_to profile_path(#object.profile) }
format.js { render }
else
format.html { redirect_to #profile, :alert => 'Unable to add object' }
end
end
end
In views/objects/create.js.erb:
$('#objectList').append("<%= escape_javascript(render #profile.object)) %>");
So I have a form calling an action in another controller to which I want to add ajax. What happens at the moment is that I need to reload the profile to show the newly created object. What am I doing wrong?
CLARIFICATION: Other than the create action in the ObjectsController, I only reference #object once elsewhere. That's in the ProfilesController's show action:
def show
#profile = Profile.find(params[:id])
#superlative = #profile.superlatives.new`
end

Answer 1

Not sure if this is a full code snippet for your create action, but looks like you are trying to call render on an instance variable that doesn't exist... #profile is never set in the create method in the ObjectController...
Perhaps you meant to type $('#objectList').append("<%= escape_javascript(render #object)) %>");
Also noticed that in your existing code you're making a call to render #profile.object, but the Profile class has a has_many relationship with your Object class, so if that was the right code, then you should type render #profile.objects (plural, not singular).
But I would think you would likely want the code I mentioned above, since you are appending onto the list of objects, not rendering the list again?