Methods for limiting the Rails render format to html

I have a Rails 2.1.2 site that only has html templates e.g. jobs.html.erb, so when I request a restful resource:

www.mysite.com/jobs/1

It renders my job in html, however, if I request:

www.mysite.com/jobs/1.xml

I get the error:

Template is missing Missing template jobs/show.xml.erb in view path c:/workspace/mysite/app/views

What's worse is that I can also request something like

www.mysite.com/jobs/1.xyz

And indeed I see the error:

Template is missing Missing template jobs/show.xyz.erb in view path c:/workspace/mysite/app/views

To stricly present just html content, what is the cleanest and simplest way to tell Rails that I don't want to render anything other than .html.erb files.

It is important to note that:

Some of my controller actions contain conditional calls to the render() method whilst others use the default Rails behaviour i.e. if you don't call render() then the template named youraction.html.erb will be rendered.
My code does not use the responds_to() method

It would be great if the solution was not at the render/responds_to level as I would have to modify a significant number of actions. Perhaps there is a way to configure Rails so that only html templates are rendered?

Solution

If you don't want to use responds_to, you can do this:

class ApplicationController < ActionController::Base
  before_filter :allow_only_html_requests

  ...

  def allow_only_html_requests
    if params[:format] && params[:format] != "html"
      render :file => "#{RAILS_ROOT}/public/404.html"
    end
  end

  ...

end

That will run before all requests and only let those that do not specify format at all, or that specify html format through. All others get 404'd. You can create a public/406.html if you want to return 406 not acceptable.