# Architecture question: reusing code across controllers?

**URL:** <https://www.ruby-forum.com/t/architecture-question-reusing-code-across-controllers/103937>\
**Category:** Rails\
**Created:** [May 11, 2007, 7:54pm UTC](https://www.ruby-forum.com/t/architecture-question-reusing-code-across-controllers/103937 "2007-05-11T19:54:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jacob](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/f1d935/32.png) [@jacob](https://www.ruby-forum.com/u/jacob)\
**Post date:** [May 11, 2007, 7:54pm UTC](https://www.ruby-forum.com/t/architecture-question-reusing-code-across-controllers/103937/1 "2007-05-11T19:54:10Z")

</div>

Hi all,

I’m building my first Rails app and looking for some advice about how  
to architect my controllers. I’m essentially building a sales tracker.  
Sellers log in and post their sales; buyers log in and see a list of  
their purchases. Admins can do everything sellers and buyers can do.

So far I’ve built out the admin controller. It now has most of the  
app’s functionality, and in the process I’ve gotten comfortable with  
Rails. Now, I’m ready to build the more specific app functionality  
which will allow sellers and buyers to log in and interact with the  
data from their different perspectives. Here’s where I hit an  
architecture question and would love some advice.

My question: Should i create separate controllers for both buyers and  
sellers? Initially I thought yes, since the options available to these  
two sets of users will be different. But now I’m realizing that they  
will also share quite a bit of code with each other and with the admin  
controller. For example, “view sale details” is the same whether it’s  
in a buyer context, a seller context, or an admin context.

How best should I architect my app to keep DRY? Should I make the  
buyer and seller controllers children of the admin controller, thus  
inheriting its methods? Somehow this doesn’t seem quite right. Is  
there some other way to reuse code across multiple controllers? Or  
maybe these shouldn’t be separate controllers after all?

Thanks in advance and please let me know if you need more specific  
info to be able to offer advice.

Cheers,  
Jacob

---

<div class="post-metadata">

**Author:** ![jacob](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/f1d935/32.png) [@jacob](https://www.ruby-forum.com/u/jacob)\
**Post date:** [May 11, 2007, 9:45pm UTC](https://www.ruby-forum.com/t/architecture-question-reusing-code-across-controllers/103937/2 "2007-05-11T21:45:22Z")

</div>

On May 11, 2007, at 11:52 AM, Jacob wrote:

> Rails. Now, I’m ready to build the more specific app functionality  
> which will allow sellers and buyers to log in and interact with the  
> data from their different perspectives. Here’s where I hit an  
> architecture question and would love some advice.

So far, so good.

> My question: Should i create separate controllers for both buyers and  
> sellers? Initially I thought yes, since the options available to these  
> two sets of users will be different. But now I’m realizing that they  
> will also share quite a bit of code with each other and with the admin  
> controller. For example, “view sale details” is the same whether it’s  
> in a buyer context, a seller context, or an admin context.
> 
> How best should I architect my app to keep DRY?

I hesitate to give a hard and fast rule, but based on your description,  
I would look at moving the methods from your admin controller that will  
be used for the buyer and seller, into the application controller.  
Because  
all controllers inherit from the application controller, you can put  
shared functionality there. If you are going to have other controllers  
that do not need this functionality, I would look at making a subclass  
of the application controller that contains the shared functionality and  
then having the admin, buyer, and seller controllers inherit from that.

> Should I make the  
> buyer and seller controllers children of the admin controller, thus  
> inheriting its methods? Somehow this doesn’t seem quite right.

That does not sound good to me, either.

> Is  
> there some other way to reuse code across multiple controllers?

See my comments above.

> Or  
> maybe these shouldn’t be separate controllers after all?

That’s really a judgement call that only you can make. Based on your  
description, I would tend to make them separate controllers.

> Thanks in advance and please let me know if you need more specific  
> info to be able to offer advice.
> 
> Cheers,  
> Jacob

## Kim

Kim S. - principal, Shrier and Deihl - [mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
Remote Unix Network Admin, Security, Internet Software Development  
Tinker Internet Services - Superior FreeBSD-based Web Hosting  
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