# Newbie Question: Howto insert a variable into a new form **URL:** \ **Category:** Rails\ **Created:** [July 15, 2008, 11:41pm UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170 "2008-07-15T23:41:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![ptremblett](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/dc4da7/32.png) [@ptremblett](https://www.ruby-forum.com/u/ptremblett)\ **Post date:** [July 15, 2008, 11:41pm UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170/1 "2008-07-15T23:41:25Z")
I am trying to populate some fields in a new form before I display it. I know that if I do this: @mapper = Mapper.new(:consultant\_id =\> ‘Fred’) It works and Fred is displayed in the form but in this case consultant\_id is stored as a variable in sessions as it is assigned when the consultant logs in. So what I want to do is substitute “Fred” with my session variable: session[:consultant\_id] If I do this: @mapper = Mapper.new(:consultant\_id =\> ‘#{session[:consultant\_id]}’) The code appears in the form not the name. I have tried a number of other ways but they all caused the app to bomb. Can someone please show me the correct way to do this. Thanks, Paul Thompson. ---
**Author:** ![ptremblett](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/dc4da7/32.png) [@ptremblett](https://www.ruby-forum.com/u/ptremblett)\ **Post date:** [July 15, 2008, 11:46pm UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170/2 "2008-07-15T23:46:06Z")
Have you tried just the following? I’ve never use Mapper, so I don’t know of any caveats that might apply to it specifically @mapper = Mapper.new(:consultant\_id =\> session[:consultant\_id]) On Jul 15, 3:40 pm, “Paul Jonathan T.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![ptremblett](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/dc4da7/32.png) [@ptremblett](https://www.ruby-forum.com/u/ptremblett)\ **Post date:** [July 15, 2008, 11:57pm UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170/3 "2008-07-15T23:57:13Z")
Thanks and yes I have tried that. It does not bomb but nothing appears when the form is displayed either ☹ 2008/7/16 Sean C. Hess [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): ---
**Author:** ![ptremblett](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/dc4da7/32.png) [@ptremblett](https://www.ruby-forum.com/u/ptremblett)\ **Post date:** [July 15, 2008, 11:59pm UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170/4 "2008-07-15T23:59:33Z")
What happens if you put the following before your code? \<%= :consultant\_id %\> - \<%= session[:consultant\_id] %\> Just making sure the variables are set the way you think they are. On Tue, Jul 15, 2008 at 3:56 PM, Paul Jonathan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![ptremblett](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/dc4da7/32.png) [@ptremblett](https://www.ruby-forum.com/u/ptremblett)\ **Post date:** [July 16, 2008, 12:24am UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170/5 "2008-07-16T00:24:43Z")
Sean, thanks for your help. Your first suggestion: @mapper = Mapper.new(:consultant\_id =\> session[:consultant\_id]) works just fine. What happened is that I save the data to sessions via a before filter in application.rb Somehow I forgot to run the filter and this came to light when your second suggestion failed to work. Thanks for the help, I am not a programming noob but still very much a noob to rails and object orientated programming. If I were confident in my code, I would likely have picked up the problem earlier but not being sure about the code, when it failed I just zeroed in on it. Thank you once again. It is guys like you that make the rails community great thing it is today. 2008/7/16 Sean C. Hess [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): ---
**Author:** ![ptremblett](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/dc4da7/32.png) [@ptremblett](https://www.ruby-forum.com/u/ptremblett)\ **Post date:** [July 16, 2008, 12:26am UTC](https://www.ruby-forum.com/t/newbie-question-howto-insert-a-variable-into-a-new-form/143170/6 "2008-07-16T00:26:28Z")
Thanks for the flattery. I’m a newbie myself, so it’s good to hear I could help somebody 😃 ~sean On Tue, Jul 15, 2008 at 4:23 PM, Paul Jonathan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)