Rails routing: Using constraints to avoid "Missing template" errors

You can use constraints in your routes.rb to avoid getting ActionView::MissingTemplate errors when wrong routes are called. Instead, the user will see a 404.

If you want multiple routes to use the same constraint you can use the block syntax:

Copyconstraints(format: 'html') do
  resources :pages
  resources :images
end

If you want constraints only on certain routes, you can do:

Copyget '/users/account' => 'users#account', constraints: { format: 'html' }

Tip

You can also avoid this error type through format constraints in your controllers and use correct file names.