Rails's PUT request via link_to becomes POST - ruby-on-rails

Question

In views file, my code is similar with:
<%= link_to refresh_post_user_post_path(#user,#post), :method => :put%>
In routes.rb:
resources :users do
resources :posts do
member do
put :refresh_post
end
end
end
The interesting thing is when inspecting the request object in controller:
def refresh_post
... ...
p request.method # => POST
p request.request_method # => PUT
... ...
end
I know method and request method are different, but where's POST request from?
Moreover:
$ rake routes
refresh_post_user_post_path PUT /users/:user_id/posts/:id/refresh_post, {:action => "refresh_post", :controller => "posts"}
I am with Rails 3.0.11 and Ruby ree-1.8.7, everything above works with no exception. But any body knows how come the request is a POST?

Answer 1

Rails emulates "advanced" request types (PUT, DELETE, etc) with a POST type. This is because browsers typically support only GET and POST.
So rails accepts a POST request and looks for a :method parameter. If such parameter is found, it updates request type accordingly (so that your routes can work, for example).

Answer 2

The truth is request.method always returns POST, no matter for a PUT or POST request and no matter the controller method is a default 'update' or a custom one. Sergio, you are right.
It is from Rails' doc for request class:
method:
Returns the original value of the environment’s REQUEST_METHOD, even if it was overridden by middleware
request_method:
Returns the HTTP method that the application should see. In the case where the method was overridden by a middleware (for instance, if a HEAD request was converted to a #GET, or if a _method parameter was used to determine the method the application should use), this method returns the overridden value, not the original.
The interesting thing is even if it is a PUT request, in the log file it says like:
Started POST "/users/251/posts/1234" for 127.0.0.1 at Fri Jan 18 21:48:21 +0800 2012
This happens in Rails 3.0.11, and log file doesn't tell it is a PUT request at all. However in later versions, it has been fixed:
https://github.com/rails/rails/commit/17a91a6ef93008170e50c073d1c3794f038a0a33
And the log becomes as friendly as:
Started PUT "/users/251/posts/1234" for 127.0.0.1 at Fri Jan 18 21:48:21 +0800 2012