How to show custom 404 per controller?

Is 开发者_开发百科it possible to show different error pages based on the controller?

For Rails < 3.0.

Yes, it is possible. I use this method in my application controller to render 404 message:

def render_optional_error_file(status_code)
  status = interpret_status(status_code)[0,3]
  if status == "404"
    render :template => "/errors/404.html.erb", :status => status
  else
    render :template => "/errors/error.html.erb", :status => status
  end
end

So, the only thing you need to do is to write this method for each controller, or you can change render line to something like this:

render :template => error_page, :status => status

and add method:

def error_page
  "/errors/404.html.erb"
end

Then you only need to write error_page method in each controller, where you want to change default error page.

EDIT: Ups, I've just noticed that this method is deprecated in Rails 3. So there should be another way of doing it.

For Rails >=3.0:

Here is one example solution for this. Just add:

rescue_from ActionController::RoutingError, :with => :render_404

and add render_404 method:

def render_404
  render :file => "errors/404.html.erb", :status => 404
end

Or if you want to add 404.html.erb view for each controller without modifing controllers code, you can write it like this:

def render_404
  render "404.html.erb", :status => 404
end

I think it should look for this error file inside current controller's view directory. I didn't check it, but I think it should work. But remember to include 404.html.erb file in each controller's view directory. Otherwise there could be an error.