undefined method path with simple form

Question

I have albums and pictures where albums hasmany pictures

This is my routes.rb

 resources :albums do
  resources :photos
end

Instead of photos_path my path is album_photos_path In my photos/new.html.erb I'm getting this error:

undefined method photos_path' for #<#<Class:0x5232b40>:0x3cd55a0>

How I can do to instead of photos_path simple form write album_photos_path ?

My new.html.erb

<%= simple_form_for([@album, @photo]) do |f| %>
<%= f.error_notification %>

<div class="form-inputs">
<%= f.input :title %>
<%= f.input :description %>
</div>

<div class="form-actions">
<%= f.button :submit %>
</div>
<% end %>

Answer 1

You can specify url in your form. Like this:

<%= simple_form_for @photo, url: album_photos_path do |f| %>
  <%= f.error_notification %>

  <div class="form-inputs">
    <%= f.input :title %>
    <%= f.input :description %>
  </div>

  <div class="form-actions">
    <%= f.button :submit %>
  </div>
<% end %>

But your code should also work. In your new action did you initialize both @album and @photo, something like:

def new
  @album = Album.find params[:album_id]
  @photo = @album.pictures.build
end

P.S above code is just a sample code and if both variables(@album and @photo) are initialized properly then rails will automatically generate correct url.