button to save current page in rails 3.2 - ruby-on-rails

Question

I need to have a button to save the current web site (just like clicking on "Save as"), I created a method in the controller which works great for any external site (like http://www.google.com) but doesn't work for the sites inside my application, I get a timeout error!. This has no explanation to me :(
Any clue what is the issue?
#CONTROLLER FILE
def save_current_page
# => Using MECHANIZE
agent = Mechanize.new
page = agent.get request.referer
send_data(page.content, :filename => "filename.txt")
end
I tried also Open URI, same problem!
#CONTROLLER FILE
def save_current_page
# => USANDO OPEN URI
send_data(open(request.referer).read, :filename => "filename.txt")
end
I'm using rails 3.2 and ruby 1.9, any help is appreciated, I already spent like 10 hours trying to make it work!!

Answer 1

Rails can only handle one request at a time. It's a never-ending standoff between the two requests - the first request is waiting for the second request, but the second request is waiting for the first request, and therefore you get a Timeout error. Even if you're running multiple instances of the app with Passenger or something, it's a bad idea.
The only way I can think to get around it would be to use conditional statements like so:
referer = URI.parse(request.referer)
if Rails.application.config.default_url_options[:host] == referer.host
content = "via yoursite.com"
else
agent = Mechanize.new
page = agent.get request.referer
content = page.content
end
send_data content, filename: "filename.txt"
A little dirty but it should get around the Timeout problem. As far a getting the actual content of a page from your own site - that's up to you. You could either render the template, grab something from cache, or just ignore it.
A much better solution would be to enqueue this code into something like Resque or Delayed Job. Then the queue could make the request and wait in line to request the page like normal. It would also mean that the user wouldn't have to wait while your application make a remote request, which is dangerous because who knows how long the page will take to respond.

Answer 2

After several hours and lots of other posts I got to a final solution:
Bricker is right in that it is not possible for rails to render more than once in a call, as taken from http://guides.rubyonrails.org/layouts_and_rendering.html "Can only render or redirect once per action"
The site also states "The rule is that if you do not explicitly render something at the end of a controller action, Rails will automatically look for the action_name.html.erb template in the controller’s view path and render it."
Then, the solution that worked great for me was to tell the controller to render to a string if a download flag (download=true) was set in :params (I also use request.url to have it working from any view in my application)
View:
= link_to 'Download', request.url+"&downloadexcel=true", :class => 'btn btn-primary btn-block'
Controller:
def acontrolleraction
#some controller code here
if params[:downloadexcel]
save_page_xls
else
# render normally
end
end
def save_page_xls
#TRESCLOUD - we create a proper name for the file
path = URI(request.referer).path.gsub(/[^0-9a-z]/i, '')
query = URI(request.referer).query.gsub(/[^0-9a-z]/i, '')
filename = #project_data['NOMBRE']+"_"+path+"_"+query+".xls"
#TRESCLOUD - we render the page into a variable and process it
page = render_to_string
#TRESCLOUD - we send the file for download!
send_data(page, :filename => filename, :type => "application/xls")
end
Thanks for your tips!