Question

I have a controller action that handles JSON requests mainly for handling datatables grid redrawing. But I have this before_filter that checks if the session has been destroyed and should redirect back to the logout action. When the request is an ajax request, the redirect happens fine. But if the request is JSON, the logs shows “Filter chain halted as :authorize rendered or redirected” but does not redirect the page at all. Any clues?

I see that the logs show that it’s processing the action as JSON:

Processing by UserController#datatable_redrawings as JSON

My Contoller method:

before_filter :auth

def auth
  if session[:username].blank?
    flash[:error] = "Please login."
    if request.xhr?
      render :js => "window.location = '/logout'"
    else
      respond_to do |format|
        format.html { redirect_to :action => "logout" }
      end
    end
  end
end

Answer 1

A redirection isn’t really RESTful, nor is sending JS when the client is expecting a JSON response. You should send an Unauthorized (401) HTTP status code or something similar.

before_filter :auth

def auth
  if session[:username].blank?
    respond_to do |format|
      format.json { render :json => [], :status => :unauthorized }
      format.html { redirect_to :action => "logout" }
    end
    return false
  end
end