Update page with ajax on form submit - nested routes - ruby-on-rails

Question

I'm trying to do something similar to adding comments to blog posts via ajax but i'm struggling to get it working. In my project, a user can have many activities and each activity can have many items.
The routing is as follows:
resources :users do
resources :activities do
resources :items
end
end
ActivitiesController.rb
#rest of code
def show
#activity = Activity.find(params[:id])
#new_item = #activity.items.build
#items = #activity.items.all.order('id DESC')
end
ItemsController.rb
#rest of code
def create
#activity = Activity.find(params[:activity_id])
#item = #activity.items.new(item_params)
respond_to do |format|
if #item.save
format.html {redirect_to user_activity_path(#activity.user_id, #activity)}
format.js
else
format.html {redirect_to :back}
end
end
end
activities/show.html.erb
<div class="row">
<div class="large-6 large-offset-3 columns">
<%= simple_form_for [#activity, #new_item], url: user_activity_items_path(#activity.user_id, #activity), remote: true do |f| %>
<%= f.input :name, required: false, :wrapper_html => { class: 'large-8 columns name' } %>
<%= f.input :cost, required: false, :wrapper_html => { class: 'large-4 columns cost' } %>
<%= f.submit "Add Item", class: 'large-4 columns button' %>
<% end %>
</div>
</div>
<div class="row">
<div class="large-6 large-offset-3 columns item-list">
<table>
<thead>
<tr>
<th>Name</th>
<th>Cost</th>
</tr>
</thead>
<tbody>
<% #items.each do |item| %>
<%= render 'item', item: item %>
<% end %>
</tbody>
</table>
</div>
</div>
activities/_item.html.erb
<tr>
<td><%= item.name %></td>
<td><%= item.cost %></td>
</tr>
items/create.js.erb
#currently empty

Answer 1

Your create.js.erb should look like
$("#getItems").last('tr').after('<%= escape_javascript(render partial: "activities/item", :locals => { :item => #item })) %>');
And on show page replace this by mine.
<div class="row">
<div class="large-6 large-offset-3 columns item-list">
<table>
<thead>
<tr>
<th>Name</th>
<th>Cost</th>
</tr>
</thead>
<tbody id="getItems">
<% #items.each do |item| %>
<%= render 'item', item: item %>
<% end %>
</tbody>
</table>
</div>
</div>