# RESTful updates, redirects and context

**URL:** <https://www.ruby-forum.com/t/restful-updates-redirects-and-context/133551>\
**Category:** Rails\
**Created:** [April 1, 2008, 4:46pm UTC](https://www.ruby-forum.com/t/restful-updates-redirects-and-context/133551 "2008-04-01T16:46:51Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![harm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/b4bc9f/32.png) [@harm](https://www.ruby-forum.com/u/harm)\
**Post date:** [April 1, 2008, 4:46pm UTC](https://www.ruby-forum.com/t/restful-updates-redirects-and-context/133551/1 "2008-04-01T16:46:51Z")

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Dear group,

Currently I am working on (surprise, surprise) a webshop with a  
shopping cart. Now I really like the whole REST thing but I constantly  
run into the same problem.  
As a user I am browsing the site and add products to the cart. This  
results in an UPDATE of the cart object and a redirect\_to :back.  
However, when I am finalizing an order I tack on some additional info  
on the cart object. In this case I want to redirect to the next step  
in the ordering process.

But this is just an example, it happens that the update of a resourse  
happens in a certain context. The context determines the finalizing  
step in the update method(or what ever method). This violates the  
stateless principe but I see no way around it. How do you guys handle  
this?

With kind regards,  
Harm

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<div class="post-metadata">

**Author:** ![harm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/b4bc9f/32.png) [@harm](https://www.ruby-forum.com/u/harm)\
**Post date:** [April 1, 2008, 4:52pm UTC](https://www.ruby-forum.com/t/restful-updates-redirects-and-context/133551/2 "2008-04-01T16:52:12Z")

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well, somethimes sheer CRUD isn’t enough. but RESTful routes let you  
add additional actions for cases like this:

# routes

map.espources :carts, :member =\> {:finalize =\> :post}

# controller

def finalize  
#your update code  
redirect\_to whatever  
end

#view  
use thhis helper: finalize\_cart\_path(@cart)

if you see code duplication in the update and finalize action, move it  
to a seperate method and call this method from both actions to stay  
DRY.

OR: if its really only the redirect, send a hidden field or some other  
paremeter to the update action from which you determine weither to  
redirect :back or redirect somewhere else.

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<div class="post-metadata">

**Author:** ![harm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/b4bc9f/32.png) [@harm](https://www.ruby-forum.com/u/harm)\
**Post date:** [April 1, 2008, 8:20pm UTC](https://www.ruby-forum.com/t/restful-updates-redirects-and-context/133551/3 "2008-04-01T20:20:33Z")

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Thank you Thorsten for your reply.  
But is that not in conflict with the whole REST principle? I mean,  
shouldn’t actions be independant of the context?  
I already defined a method called ‘remove\_item’ which also updates the  
cart but instead of adding an item deletes it. To my mind these two  
actions are the same. Both update the cart object but in one case the  
params hash is one bigger than the current object and in the other  
case one smaller. Again only the redirect differentiates the two. For  
example if you think of sending the request as an XML post both the  
results would be the same, a 200 header.

Won’t it be better if the context would be entirely kept on the client  
side? You could for example sent an Ajax request and do some voodoo  
magic in the :on\_complete parameter(I’m not that good with JS so I do  
not know if you can). For example a redirect\_to :some\_path in  
the :on\_success or :on\_complete.

But I am getting more and more the feeling that I am not being very  
practical here. 🙂

With kind regards,  
Harm

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<div class="post-metadata">

**Author:** ![harm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/b4bc9f/32.png) [@harm](https://www.ruby-forum.com/u/harm)\
**Post date:** [April 2, 2008, 6:52pm UTC](https://www.ruby-forum.com/t/restful-updates-redirects-and-context/133551/4 "2008-04-02T18:52:31Z")

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(another thorsten)  
that’s not a perfect world… 😉

> …the site and add products to the cart. This  
> results in an UPDATE of the cart object and a redirect\_to :back…

you could(!) use a create on an order object instead (asuming cart  
has\_many orders (just one option…)

> I already defined a method called ‘remove\_item’ which also updates the  
> cart but instead of adding an item deletes it.

this would in any case be a destroy action, not update.  
seems you’re concentrating your thoughts too much on the cart. the thing  
has a content and you can apply functionality to them too.

but this kind of problem happens all the time:  
take the index  
we often have more than one possible index.  
list customers  
list customers we like  
list customers we don’t like  
one index action with a param or three index actions  
index / index\_liked / index\_not\_liked ?