Optional named parameters in Padrino routes

January 11, 2015

It is not very well documented and I’m not sure its even is in the docs, but Padrino supports optional named parameters in routes. Just place your parameter inside ordinary parentheses “()” and you are good to go.

A use case could be to load an editor with a post if the named parameter :id exists and if not create a new post.

get :posts_editor, map: '/posts/editor/(:id)' do
  if params[:id]
    @post = Post.find(params[:id])
  else
    @post = Post.new
  end
  render('panels_posts_editor')
end

of if you prefer to use the with: option instead

get :posts_editor, map: '/posts/editor', with: '(:id)' do
   # Route renders like: /posts/editor/(:id)
   # Code goes here
end

It also works when using an with:array of options, where :namewould be optional.

get :posts_editor, map: '/posts/editor', with: [:id, '(:name)'] do
   # Route renders like: /posts/editor/:id/(:name)
   # Code goes here
end

The above examples lets you then use the reverse lookup like this without any errors or problem.

# Without :id
<%= link_to('New post', url(:posts_editor)) %>
# and with :id
<%= link_to('New post', url(:posts_editor, id: 2)) %>

Happy routing!