# Helpers for common Controller code

**URL:** <https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816>\
**Category:** Rails\
**Created:** [December 12, 2007, 2:47pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816 "2007-12-12T14:47:00Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 2:47pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/1 "2007-12-12T14:47:00Z")

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Another newbie question: I want to keep business logic out of my  
controller. For example I had a routine that did a slightly  
complicated computation and it didn’t seem to belong in the  
controller. But the calculation has nothing to do with display per-se.  
It takes an integer in and returns a different integer.

So I thought to put it in the corresponding helper. Is that the best  
practice?

Because I note that helpers are not automatically ‘included’ in the  
corresponding controller. I had to add an ‘include’ to the controller  
which seemed a bit lame.

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<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 5:27pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/2 "2007-12-12T17:27:36Z")

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Not really. In my experience, it works like this:

Keep Controllers and View Skinny. In other words, keep as much code out  
of the controllers and view as possible. The controller should only

1. Make basic calls to model (save, update, custom\_method\_1)
2. Assign values to use in the view
3. Alter the session, cookies, flash
4. Redirect or render

That is all a controller should do, aka the bare minimum.

Same with the view. A view should only contain

1. Simple pieces of data to display (set in the controller)
2. Simple formatting and structure with html

In your quest to keep the controller clean you have some basic options  
at hand but the primary place to stick all the stuff you don’t want in  
the controller is in the model! Put all the complicated code in the  
model and then make simple one line requests and store the return values  
in the controller (for display in the view).

In your quest to keep views clean, you have helpers and partials.  
Basically, use helpers and partials whenever possible to keep views as  
concise and clean of code as possible.

So Basically,

Controller =\> Lean, View =\> Lean  
Model =\> Picks up controller’s excess code  
Helper =\> Picks up views excess code

That’s my take anyways.

Pito wrote:

> Another newbie question: I want to keep business logic out of my  
> controller. For example I had a routine that did a slightly  
> complicated computation and it didn’t seem to belong in the  
> controller. But the calculation has nothing to do with display per-se.  
> It takes an integer in and returns a different integer.
> 
> So I thought to put it in the corresponding helper. Is that the best  
> practice?
> 
> Because I note that helpers are not automatically ‘included’ in the  
> corresponding controller. I had to add an ‘include’ to the controller  
> which seemed a bit lame.

---

<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 6:36pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/3 "2007-12-12T18:36:06Z")

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In addition to Nathan’s excellent remarks, I’d add:

1. As much formatting as possible in the stylesheet.

///ark

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<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 6:57pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/4 "2007-12-12T18:57:05Z")

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On 12 Dec 2007, at 02:34, Pito wrote:

> Because I note that helpers are not automatically ‘included’ in the  
> corresponding controller. I had to add an ‘include’ to the controller  
> which seemed a bit lame.

When you see helper, think ‘view helper’. They’re loaded automatically  
into templates. They’re not loaded into controller, because they’re  
little bits of presentation logic and so don’t belong in the  
controller normally.  
It sounds like your complicated calculation belongs in a model

Fred

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<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 8:55pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/5 "2007-12-12T20:55:57Z")

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Thanks all for the excellent points.

I held back from putting the logic in the model because it really  
wasn’t model related. It was more of a ‘business rule’ which takes a  
date in and generates two boolean and one date result. The model is a  
User table, nothing more.

That’s how I ended up with the helper but as you all say, helpers are  
more view helpers - as is evidenced by needing to do an explicit  
include in the controller.

---

<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 10:12pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/6 "2007-12-12T22:12:47Z")

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That’s just it… business rules go in models.

However, it may not go in the User model. Models in Rails are not just  
data-access objects - they are your domain models. If this code belongs  
to  
a User, it goes in the User model.

You can even have models that don’t have a table behind them.

Since I don’t know what this method actually does, I can’t tell you  
where it  
should go. However, another option is to make your own class and put it  
there. The Lib folder is a great place for classes that aren’t models.

lib/utility.rb

class Utility

# returns two dates plus the date + 10

def self.do\_something\_with\_date(date)  
return 0, 1, date + 10  
end

end

That class wil be required automatically by Rails, so you can use it  
where  
you want. In models, views, etc.

So there’s another option. How you do it depends on what you want to  
accomplish. It’s most likely that this method you’re referring to has  
some  
association with a model, so that’s where I’d put it.

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<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 8:53pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/7 "2007-12-12T20:53:25Z")

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I always felt helper should have been a folder inside the views folder  
almost. It seems like a common mistake amongst new people to rails to  
think helpers are helpers for controllers or models and I can’t blame  
them. They need a way of distinguishing helpers and view-centric more.  
It’s not really it’s own part of the MVC model yet it gets its own  
folder next to the rest of them.

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<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 10:21pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/8 "2007-12-12T22:21:36Z")

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I’d go with Brian’s approach, personally. For example, I have a file  
in my lib directory that does the rendering of a PDF, which would  
otherwise clog up my controlller. I also have Vacation and PTO  
calculations in my lib directory for an employee program.

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<div class="post-metadata">

**Author:** ![Pito](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/e68b1a/32.png) [@Pito](https://www.ruby-forum.com/u/Pito)\
**Post date:** [December 12, 2007, 10:14pm UTC](https://www.ruby-forum.com/t/helpers-for-common-controller-code/122816/9 "2007-12-12T22:14:32Z")

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One thing I have come to understand which frankly is useful knowledge is  
that whenever I tried to “go around rails”, in other words, when I tried  
to do things the “non-rails” way I always thought I had a good reason. I  
would convince myself that doing it MY way was smarter or better for my  
specific condition. What I didn’t realize was that I was just doing  
things wrong.

90% of the time it was just me not understand how beautiful and simple  
life would be if I would have just not tried to reinvent the wheel or do  
thing my way. If I just go with the rails conventions, once I learned  
what they were, it ended up making more sense to me that my way even  
did. The problem was learning them all because there are so many  
patterns and conventions to learn it can drive a man crazy.

I don’t know if this has been any one else’s experience but for me, when  
I run into a place where my opinion differs from rails convention, I do  
a long, hard look at what I want to do and try to seriously evaluate the  
possibility that I am missing something.