Rails detect if request was AJAX

Question

In my action I wish to only respond with processing if it was called from an AJAX request. How do I check?

I want to do something like this:

def acti         


        

Answer 1

The docs say that request.xhr?

Returns true if the “X-Requested-With” header contains “XMLHttpRequest”....

But BEWARE that

request.xhr? 

returns numeric or nil values not BOOLEAN values as the docs say, in accordance with =~.

irb(main):004:0> /hay/ =~ 'haystack'
=> 0
irb(main):006:0> /stack/ =~ 'haystack'
=> 3
irb(main):005:0> /asfd/ =~ 'haystack'
=> nil

It's based on this:

# File actionpack/lib/action_dispatch/http/request.rb, line 220
def xml_http_request?
  @env['HTTP_X_REQUESTED_WITH'] =~ /XMLHttpRequest/
end

so

env['HTTP_X_REQUESTED_WITH'] =~ /XMLHttpRequest/  => 0

The docs:

http://apidock.com/rails/v4.2.1/ActionDispatch/Request/xml_http_request%3F