Missing Template Should be 404 Error

I have a site I’m building that has the template dynamically chosen
based upon some parameters of the request. There are cases where a
nonexistent template will be sent to the render method. For purposes of
my application, this is not a serious, fatal error, but a simple HTTP
404 error code. Unfortunately, Rails disagrees, and it’s sending a 500
error message in production.

How can I override this behavior?

What is the justification for template missing to be treated as a 500 error instead of 404 error?

http://6brand.com/rails-custom-404-pages

Aaron Longwell escribió:

That site is similar to a lot of other stuff I’ve seen. It appears that catching missing method errors is a much more common problem than catching missing template errors.

I can’t
use method_missing, because my error happens after the call to
render (after the correct action method has begun executing)… and I don’t believe template_missing exists… but I have
found a (the?) solution.

As it turns out, rescue_action_in_public can catch the MissingTemplate
error, but I was not detecting the error properly in my previous
attempts. I was failing to use global scope when specifying Missing
Template. Here’s what works:

if exception.kind_of? ::ActionController::MissingTemplate

render :status => 404, :text => (IO.read(File.join(RAILS_ROOT, ‘public’, ‘404.html’)))
end

That code is effectively converting 500 errors from MissingTemplate into 404 errors just like other rails features. Excellent.

Notice the “::” before ActionController. Failing to include that results in the exception handler throwing an error of its own… which I didn’t notice before.