# How can I pass Ruby object to another action? **URL:** \ **Category:** Rails\ **Created:** [August 5, 2009, 10:57am UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231 "2009-08-05T10:57:04Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 5, 2009, 10:57am UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/1 "2009-08-05T10:57:04Z")
I use form\_tag like below: \<% form\_tag (my\_action) %\> \<%= submit\_tag “Submit” %\> \<% end %\> In this case, how can I pass a Ruby object to “my\_action” action? I want to pass a Hash to the next action. thanks. ---
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 5, 2009, 12:19pm UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/2 "2009-08-05T12:19:22Z")
Zhao Yi wrote: > I use form\_tag like below: > > \<% form\_tag (my\_action) %\> > > \<%= submit\_tag “Submit” %\> > > \<% end %\> > > In this case, how can I pass a Ruby object to “my\_action” action? I want > to pass a Hash to the next action. > > thanks. You can’t pass ruby objects from the form to the controller because the browser has no concept of ruby or rails or any of that stuff. However, you can build a hash to put into params like this \<%= hidden\_field\_tag “foo[bar]”, “hello” %\> which creates this situation params =\> {:foo =\> {:bar =\> “hello”}} Knowing this, you can make a hidden field tag, or set of hidden field tags, which recreates the hash you want to pass through. Ultimately, this is all that a form does: it builds a data structure inside params, which is a hash that can contain other hashes, strings, and arrays. ---
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 5, 2009, 10:22pm UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/3 "2009-08-05T22:22:38Z")
How about saving the object in a session value? session[:my\_object] = my\_object/@my\_object The next action could just retrieve it easily: my\_object/@my\_object = session[:my\_object] Pepe ---
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 6, 2009, 10:22am UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/4 "2009-08-06T10:22:19Z")
Zhao Yi wrote: > Max W. wrote: > > > You can’t pass ruby objects from the form to the controller because the > > browser has no concept of ruby or rails or any of that stuff. However, > > you can build a hash to put into params like this > > > > \<%= hidden\_field\_tag “foo[bar]”, “hello” %\> > > > > which creates this situation > > > > params =\> {:foo =\> {:bar =\> “hello”}} > > > > Knowing this, you can make a hidden field tag, or set of hidden field > > tags, which recreates the hash you want to pass through. Ultimately, > > this is all that a form does: it builds a data structure inside params, > > which is a hash that can contain other hashes, strings, and arrays. > > But when I get the hash object from params, I get a String object > instead of a hash object. Post up the form and the contents of your params hash please - you can see this in your log file. ---
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 6, 2009, 10:27am UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/5 "2009-08-06T10:27:06Z")
pepe wrote: > How about saving the object in a session value? > > session[:my\_object] = my\_object/@my\_object > > The next action could just retrieve it easily: > > my\_object/@my\_object = session[:my\_object] > > Pepe This isn’t what the session is for. It’s bad practise imo to use the session as a storage space for any arbitrary data - it’s going to fill up with a load of junk real quickly. What if two different actions happen to use the same session variable name? What if you want to get to step two of the process from somewhere else, that didn’t save the session variable? It’s just asking for trouble. Keep the session data to an absolute minimum. If you’re doing something based on the submission of a form, then that should depend on what the form sends through, not on the form and some stuff that you hope is in the session. That way you can look at the form and see what’s going on, without knowing about some mysterious session stuff. ---
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 6, 2009, 2:55am UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/6 "2009-08-06T02:55:22Z")
Max W. wrote: > You can’t pass ruby objects from the form to the controller because the > browser has no concept of ruby or rails or any of that stuff. However, > you can build a hash to put into params like this > > \<%= hidden\_field\_tag “foo[bar]”, “hello” %\> > > which creates this situation > > params =\> {:foo =\> {:bar =\> “hello”}} > > Knowing this, you can make a hidden field tag, or set of hidden field > tags, which recreates the hash you want to pass through. Ultimately, > this is all that a form does: it builds a data structure inside params, > which is a hash that can contain other hashes, strings, and arrays. But when I get the hash object from params, I get a String object instead of a hash object. ---
**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\ **Post date:** [August 6, 2009, 3:30pm UTC](https://www.ruby-forum.com/t/how-can-i-pass-ruby-object-to-another-action/173231/7 "2009-08-06T15:30:31Z")
What about initializing the object with the params values? Something like foo = MyObject.new(params[:foo]) On Aug 6, 9:27 am, Max W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)