Question

I’ve just started to use Partials in my rails application, at the moment i have the following code in my application.html.erb

<%= render 'categories/categorieslist' %>

This links to _categorieslist.html.erb in my views/categories/ folder

At the moment this partial contains hard coded hyperlinks

<ul class="unstyled">
    <li style="padding-bottom:5px"><a href="#">Item A&raquo;</a></li>
    <li style="padding-bottom:5px"><a href="#">Item B&raquo;</a></li>
</ul>

My aim is to have these categories coming from the database, e.g

<ul class="unstyled">
    <% @categories.each do |category| %>
        <li style="padding-bottom:5px"><a href="#"><%= category.name %> &raquo;    </a></li>
    <% end %>
</ul>

I have tried adding a categorieslist method in the categories controller e.g

def categorieslist
 @categories = Category.all
  respond_to do |format|
     format.html # index.html.erb
     format.json { render json: @categories }
   end
  end

but this is not being called by the partial (and i don’t feel this is even the correct way to do it), and is showing the error

NoMethodError in Store#index

on the line <% @categories.each do |category| %>

My question is how do i pass into the partial in the application.html.erb file, the categories object that usually would come from a controller method in the categories controller?

Any help would be great.

Answer 1

You can send locales with your partial call in your view and pass variables to that partial.

For example (this is a partial shortcut):

Your view from which you call the partial

<%= render 'categories/categorieslist', :all_categories => @categories %>

Your partial categories/_categorieslist.html.erb (note there is no @ with the variable)

<ul class="unstyled">
  <% all_categories.each do |category| %>
    <li style="padding-bottom:5px"><a href="#"><%= category.name %> &raquo;    </a></li>
  <% end %>
</ul>

For further information (and the long version), see 3.4.4 Passing Local Variables in the Rails Guides.