This method is deprecated or moved on the latest stable version.
The last existing version (v2.3.8) is shown here.
template_format()
public
Returns a symbolized version of the :format parameter of
the request. If no \format is given it
returns :jsfor Ajax requests and :html otherwise.
# File actionpack/lib/action_controller/request.rb, line 187
def template_format
parameter_format = parameters[:format]
if parameter_format
parameter_format
elsif xhr?
:js
else
:html
end
end