# Multiview: Format fallback from fbml to html (register\_alias/request.format)
**URL:** \
**Category:** Rails\
**Created:** [July 9, 2008, 11:47pm UTC](https://www.ruby-forum.com/t/multiview-format-fallback-from-fbml-to-html-register-alias-request-format/142637 "2008-07-09T23:47:56Z")\
**Posts on this page:** 1\
**Page:** 1
**Author:**  [@Paul\_Canavese](https://www.ruby-forum.com/u/Paul_Canavese)\
**Post date:** [July 9, 2008, 11:47pm UTC](https://www.ruby-forum.com/t/multiview-format-fallback-from-fbml-to-html-register-alias-request-format/142637/1 "2008-07-09T23:47:56Z")
I’m using Rails 2.1 with the Multiview template mechanism to create a
hybrid Facebook and public site. For the most part, there are
analogous views across the two. Since Facebook supports a subset of
HTML, some of my HTML views and partials could be shared across the
two.
I have registered a Mime type alias for FBML in my mime\_types.rb:
Mime::Type.register\_alias(“text/html”, :fbml)
and have a filter in my controller to set it appropriately:
request.format = :fbml
That all seems fine.
I would like to use an FBML template (e.g. “foo.fbml.erb”) if it
exists, but otherwise fall back to an HTML template (e.g.
“foo.html.erb”). I have seen references that it should work like this
already (e.g.
[Locomotivation.com is for sale | HugeDomains](http://locomotivation.com/2008/06/28/redesign-your-site-in-place-using-rails-custom-mime-types)),
but I get “Template is missing” errors if the FBML template is not
there.
It seems to work to name common templates without a format (e.g.
“foo.erb”), which I am doing now, but is there a way to get it to
default back to HTML first?
Regards,
Paul