# Multipage Forms

**URL:** <https://www.ruby-forum.com/t/multipage-forms/225917>\
**Category:** Rails\
**Created:** [August 20, 2006, 5:52am UTC](https://www.ruby-forum.com/t/multipage-forms/225917 "2006-08-20T05:52:14Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![The\_Great\_Mochini](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/8491ac/32.png) [@The\_Great\_Mochini](https://www.ruby-forum.com/u/The_Great_Mochini)\
**Post date:** [August 20, 2006, 5:52am UTC](https://www.ruby-forum.com/t/multipage-forms/225917/1 "2006-08-20T05:52:14Z")

</div>

I think this may actually be an object oriented programming question.  
Not only am I new to Ruby and Rails, but I’m also coming from a  
functional PHP background, so this whole OO approach to web programming  
is new to me.

I have a three page registration form and I am trying to determine best  
practices for managing the data across forms in a session. I would  
like each form to validate before passing the user along to the next  
page. The data will be ultimately be distributed across 6 different  
tables, so the validation criteria for the registration form is spread  
accross the 6 repective model objects.

My thought is to create a non-ActiveRecord model called “Registration”  
and have it create the various model objects as instance variables upon  
instantiation:

class Registration  
def initialize  
@member = Member.new  
@membership = Membership.new  
@donations = Donation.new  
…  
end  
end

and then save this in this object in the session. When I need to  
validate the form data, I could do something like this in the  
registration controller:

@registration = session[:registration] ||= Registration.new  
@member = @registration.member  
@member.attributes = params[:member]  
redirect\_to :action =\> ‘next\_page’ if @member.valid?

That way, I can still use the model (and ActiveRecord) to handle the  
nitty gritty of form validation and I only need to manage one object in  
the session. Also, if I have a form with data that belongs in three  
seperate models how do I validate that data across the various models?  
My guess is to add something like this in my registration model:

def valid?  
@member.valid?  
@membership.valid?  
@donation.valid?  
@errors =  
@member.errors.merge(@membership.errors).merge(@donation.errors)  
end

And then this in the view

\<%= error\_messages\_for ‘registration’ %\>

Does that look right? I’d like to know if these are common best  
practices for handling multipage forms in Rails and if not, how do the  
rest of you do it?

Thanks,  
Greg

---

<div class="post-metadata">

**Author:** ![The\_Great\_Mochini](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/8491ac/32.png) [@The\_Great\_Mochini](https://www.ruby-forum.com/u/The_Great_Mochini)\
**Post date:** [August 29, 2006, 6:29pm UTC](https://www.ruby-forum.com/t/multipage-forms/225917/2 "2006-08-29T18:29:50Z")

</div>

There is one very important issue to keep in mind here: ActiveRecord  
models  
aren’t fully serializable. This means that you can’t create a model and  
throw it into the session without saving, as you will lose the data and  
the  
app will probably crash. I recently had to deal with this same situation  
(model information over like 6 pages) and it took us a while to figure  
out a  
good solution. Unfortunately the best solution was keeping our own hash  
in  
the session and only when we are done collecting all of the data do we  
pull  
those values into a new model for validation and saving.

If you are ok saving a partially complete AR object, then you’re fine  
using  
the session (for note, only the ID is guarenteed to be saved, AR repolls  
from the database when needed).

Hope that helps. Just remember that even though placing unsaved AR  
objects  
in the session may be working for you, there is no guarentee that it  
will  
work anywhere else.

Jason

---

<div class="post-metadata">

**Author:** ![The\_Great\_Mochini](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/8491ac/32.png) [@The\_Great\_Mochini](https://www.ruby-forum.com/u/The_Great_Mochini)\
**Post date:** [August 29, 2006, 6:31pm UTC](https://www.ruby-forum.com/t/multipage-forms/225917/3 "2006-08-29T18:31:50Z")

</div>

I try to avoid using the session as much as possible for these. Your  
forms  
are bound to models with validation, so just let them do the work for  
you.  
You can do all sorts of cool things to avoid validating fields until you  
need to.

I don’t think there’s any reason to make your own model that you’ll  
store in  
session just to wrap existing models. Use them as they are and save the  
records. If, for some reason, you don’t want to save the record  
(incomplete  
transaction, etc) you could just store the object directly to the  
session  
and only save it upon completion.

However, for a shopping cart, there’s actually some value in saving as  
they  
go becuase you’d have some data you could look at to help find out why  
people left your store in the middle of a transaction. Just add an  
additional status field to your table… 0 for default, 1 for submitted,  
2  
for in process, 3 for fulfillment, 4 for complete, 5 for cancelled… etc

This is just off the top of my head though. There are lots of ways to do  
this.

---

<div class="post-metadata">

**Author:** ![The\_Great\_Mochini](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/8491ac/32.png) [@The\_Great\_Mochini](https://www.ruby-forum.com/u/The_Great_Mochini)\
**Post date:** [August 29, 2006, 5:32pm UTC](https://www.ruby-forum.com/t/multipage-forms/225917/4 "2006-08-29T17:32:44Z")

</div>

The Great Mochini wrote:

> I think this may actually be an object oriented programming question.  
> Not only am I new to Ruby and Rails, but I’m also coming from a  
> functional PHP background, so this whole OO approach to web programming  
> is new to me.
> 
> I have a three page registration form and I am trying to determine best  
> practices for managing the data across forms in a session. I would  
> like each form to validate before passing the user along to the next  
> page. The data will be ultimately be distributed across 6 different  
> tables, so the validation criteria for the registration form is spread  
> accross the 6 repective model objects.
> 
> My thought is to create a non-ActiveRecord model called “Registration”  
> and have it create the various model objects as instance variables upon  
> instantiation:
> 
> class Registration  
> def initialize  
> @member = Member.new  
> @membership = Membership.new  
> @donations = Donation.new  
> …  
> end  
> end
> 
> and then save this in this object in the session. When I need to  
> validate the form data, I could do something like this in the  
> registration controller:
> 
> @registration = session[:registration] ||= Registration.new  
> @member = @registration.member  
> @member.attributes = params[:member]  
> redirect\_to :action =\> ‘next\_page’ if @member.valid?
> 
> That way, I can still use the model (and ActiveRecord) to handle the  
> nitty gritty of form validation and I only need to manage one object in  
> the session. Also, if I have a form with data that belongs in three  
> seperate models how do I validate that data across the various models?  
> My guess is to add something like this in my registration model:
> 
> def valid?  
> @member.valid?  
> @membership.valid?  
> @donation.valid?  
> @errors =  
> @member.errors.merge(@membership.errors).merge(@donation.errors)  
> end
> 
> And then this in the view
> 
> \<%= error\_messages\_for ‘registration’ %\>
> 
> Does that look right? I’d like to know if these are common best  
> practices for handling multipage forms in Rails and if not, how do the  
> rest of you do it?
> 
> Thanks,  
> Greg

Greg, have you tried this? If so, what were your results?

I’m struggling with the same concept here – coming from a coldfusion  
background. It’s not difficult to save various objects (or one master  
object in your case) to the session and manipulate that data, but it’s  
considerably more difficult to get the framework validation working on  
multiple models accross multiple forms and properly display the errors,  
and properly handle the form redirects/resubmits as necessary. I’m  
amazed that there aren’t tons of examples of this sort of thing floating  
around – it’s such a basic web application thing, but so far I’ve found  
almost nothing on it. One link that was somewhat helpful is here:  
[http://www.nabble.com/Validating-two-models-from-one-form-t1421132.html](http://www.nabble.com/Validating-two-models-from-one-form-t1421132.html)

I’m looking at finishing a simple shopping cart checkout, with forms in  
this order: Customer info → credit card info (with payment amount in  
this form). My db tables/models are “order” (contains customer info),  
“credit\_card” and “payment”, one-to-many between each going left to  
right.

First I save the customer info into the session (session[:order]), and  
proceed to the credit\_card / payment amount form. When that is  
submitted, I pull the order (customer info) out of the session, push the  
payment into the credit card (@credit\_card.payments \<\< @payment), push  
the credit card into the order (@order.credit\_cards \<\< @credit\_card),  
and save the @order. The save works fine, but getting it to validate  
properly has been a nightmare.

Anyway, I’m very curious to see responses to this post as I think for  
seasoned web deveopers moving to RoR, this _must_ be a very common  
issue. Come on, Rails gurus! help us out! Surely there are some common  
practices used in Rails for this sort of thing??

-KG