Rails - Aug 2006 - How do CRUD and REST work for a wizard-style application?

I''m rewriting an application with the intention to use the elegant CRUD
and REST design principles as outlined by DHH in his RailsConf
Keynote[1].

The question is: how do you use those principles for an application
that is of a sequential nature?

The application works much like an MS Windows wizard: user begins at
screen foo. After doing (or not) some stuff in screen foo, he is taken
to screen bar, and from there to screen baz, etc. (the order of the
screens may be altered and/or reversed). The application is essentially
about walking the user through a sequential procedure.


A common solution would be to define each screen as an action. I.e. the
ProcedureController would contain actions #foo, #bar, #baz, etc. This
obviously does not remotely resemble anything like the above mentioned
CRUD/REST principles, in particular the neat "7 standard actions per
controller" design[2].

Can the CRUD/REST model, in whole or part, be applied such an
application?

-Alder
--
[1]
http://blog.scribestudio.com/articles/2006/07/09/david-heinemeier-hansson-railsconf-2006-keynote-address

[2] index, new, create, show, edit, update, and destroy, see:
http://scottraymond.net/articles/2006/07/20/refactoring-to-rest


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

> A common solution would be to define each screen as an action. I.e. the
> ProcedureController would contain actions #foo, #bar, #baz, etc. This
> obviously does not remotely resemble anything like the above mentioned
> CRUD/REST principles, in particular the neat "7 standard actions per
> controller" design[2].

Hi

the first thing Ill have to say is that I havent actually worked with 
this technique yet. Ive just watched the Keynote and read the S. Raymond 
article, so YMMV.

The thing is tho, Im trying to create exactly that - a wizard - at the 
moment. And I think its not too hard actually.


First thing: The problem with an action for each step in the wizard. I 
personally dont find that too bad -- even Scott Raymond does it, with 
his about controller, which has a lot of non-standard actions. However, 
if you want to avoid that, you could, I think simply add a case 
statement into the view of your index action, displaying only that part 
of the wizard you need at the moment, like so:

case params[:page]
when 2
  # display page 2
when 3
  # display page 3
else
  # display page 1
end


Second thing: The problem with standard actions. That should be possible 
if you dont actually save the data to the database as long as the wizard 
is running, but into a session instead. Then, when the user has entered 
everything, he/she can view all the data and either go back and change 
something, or click the final "Save this" button, which points to a 
standard "create" action. This behaviour is also much more
wizard-like,
imo -- an install wizard, for example, also only starts to actually 
install once youve given it *all* the information it wants.

Again, your mileage may vary. I havent really tried any of this stuff 
out (yet).

Hoping to Help,
Daniel

-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

My first thought after reading your email was: DON''T PUT IT IN
SESSION!!

And then I remembered, Rails can put session into the database to
create the "share-nothing" environment. So if the wizard should be
completed in a short amount of time, session works. Yea Rails!

I am preparing to create a wizard myself. I am planning to use
acts_as_state_machine to keep track of what page the user was on. This
would allow the user to save the information to the database for
extended periods of time (a requirement of my application) before
completing the wizard. So if your user would be completing the wizard
over several sessions, this may be a better route to take.

Carl

On 8/28/06, Daniel Jilg
<rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
>
>
> > A common solution would be to define each screen as an action. I.e.
the
> > ProcedureController would contain actions #foo, #bar, #baz, etc. This
> > obviously does not remotely resemble anything like the above mentioned
> > CRUD/REST principles, in particular the neat "7 standard actions
per
> > controller" design[2].
>
>
> Hi
>
> the first thing Ill have to say is that I havent actually worked with
> this technique yet. Ive just watched the Keynote and read the S. Raymond
> article, so YMMV.
>
> The thing is tho, Im trying to create exactly that - a wizard - at the
> moment. And I think its not too hard actually.
>
>
> First thing: The problem with an action for each step in the wizard. I
> personally dont find that too bad -- even Scott Raymond does it, with
> his about controller, which has a lot of non-standard actions. However,
> if you want to avoid that, you could, I think simply add a case
> statement into the view of your index action, displaying only that part
> of the wizard you need at the moment, like so:
>
> case params[:page]
> when 2
>   # display page 2
> when 3
>   # display page 3
> else
>   # display page 1
> end
>
>
> Second thing: The problem with standard actions. That should be possible
> if you dont actually save the data to the database as long as the wizard
> is running, but into a session instead. Then, when the user has entered
> everything, he/she can view all the data and either go back and change
> something, or click the final "Save this" button, which points to
a
> standard "create" action. This behaviour is also much more
wizard-like,
> imo -- an install wizard, for example, also only starts to actually
> install once youve given it *all* the information it wants.
>
> Again, your mileage may vary. I havent really tried any of this stuff
> out (yet).
>
> Hoping to Help,
> Daniel
>
> --
> Posted via http://www.ruby-forum.com/.
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

Daniel Jilg wrote:
> > A common solution would be to define each screen as an action. I.e.
the
> > ProcedureController would contain actions #foo, #bar, #baz, etc. This
> > obviously does not remotely resemble anything like the above mentioned
> > CRUD/REST principles, in particular the neat "7 standard actions
per
> > controller" design[2].
>
>
> Hi
>
> the first thing Ill have to say is that I havent actually worked with
> this technique yet. Ive just watched the Keynote and read the S. Raymond
> article, so YMMV.
>
> The thing is tho, Im trying to create exactly that - a wizard - at the
> moment. And I think its not too hard actually.
Take a look at the Acts as Wizard plugin.

http://wiki.rubyonrails.org/rails/pages/Acts+As+Wizard+Plugin
> First thing: The problem with an action for each step in the wizard. I
> personally dont find that too bad -- even Scott Raymond does it, with
> his about controller, which has a lot of non-standard actions. However,
Most of Raymond''s application is modular and object-focused - a classic
fit for the CRUD/REST model. It''s a far cry from the sequential,
proocedure oriented nature of a tutorial.

And yes, you can see the CRUD/REST model breaks on stuff that deviates
from the above (modular and object-focused) norm.
> if you want to avoid that, you could, I think simply add a case
> statement into the view of your index action, displaying only that part
> of the wizard you need at the moment, like so:
>
> case params[:page]
> when 2
>   # display page 2
> when 3
>   # display page 3
> else
>   # display page 1
> end
An idea I like is to instead have Tutorial as a model, with a
TutorialsController and the usual crud actions, so:

example.com/tutorials/23 # display tutorial with ID 23

Pages are "cuts" of tutorial objects, so we can use the nifty new ;
from Simply Restful to fethc any particular page, so:

example.com/tutorials/23;42 # display page 42 of the tutorial with ID
23
> Second thing: The problem with standard actions. That should be possible
> if you dont actually save the data to the database as long as the wizard
> is running, but into a session instead. Then, when the user has entered
> everything, he/she can view all the data and either go back and change
> something, or click the final "Save this" button, which points to
a
> standard "create" action. This behaviour is also much more
wizard-like,
> imo -- an install wizard, for example, also only starts to actually
> install once youve given it *all* the information it wants.
Interesting idea, thanks. It does make things easier.
> Again, your mileage may vary. I havent really tried any of this stuff
> out (yet).
>
> Hoping to Help,
> Daniel
> 
> -- 
> Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

Carl Fyffe wrote:
> My first thought after reading your email was: DON''T PUT IT IN
SESSION!!
>
> And then I remembered, Rails can put session into the database to
> create the "share-nothing" environment. So if the wizard should
be
> completed in a short amount of time, session works. Yea Rails!
>
> I am preparing to create a wizard myself. I am planning to use
> acts_as_state_machine to keep track of what page the user was on. This
> would allow the user to save the information to the database for
> extended periods of time (a requirement of my application) before
> completing the wizard. So if your user would be completing the wizard
> over several sessions, this may be a better route to take.
>
> Carl
>
Have you looked at the Acts as Wizard plugin?

http://wiki.rubyonrails.org/rails/pages/Acts+As+Wizard+Plugin

-Alder


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

I wrote up a little plugin for doing wizard like work, you can check it
out at:
  http://svn.trac.washington.edu/svn/plugins/multi_stage_wizard/

The easiest way to use it is to persist the object in the user''s
session, however you can get around that if you want to.  You might
also look into Tableless Models if you are using your wizard to model a
process instead of incrementally filling out a record.

Hope that helps, send me an email if you have any questions,
  .adam


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

Daniel Jilg wrote:
>
> Second thing: The problem with standard actions. That should be possible
> if you dont actually save the data to the database as long as the wizard
> is running, but into a session instead. Then, when the user has entered
What on earth is wrong with saving to the database? If you model
correctly you will have a Script and Submitted Script. Why shouldn''t a
user be able to come back to a partially completed script tomorrow?

The session system is merely there to provide an illusion of state
between what are actually unconnected HTTP requests to various
webservers. It should really be nothing more than a bunch of pointers
to stuff *stored in the database*.


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

On 9/11/06, NeilW <aldursys-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
>
> Daniel Jilg wrote:
> >
> > Second thing: The problem with standard actions. That should be
possible
> > if you dont actually save the data to the database as long as the
wizard
> > is running, but into a session instead. Then, when the user has
entered
>
> What on earth is wrong with saving to the database? If you model
> correctly you will have a Script and Submitted Script. Why
shouldn''t a
> user be able to come back to a partially completed script tomorrow?
Because validations on models assume the model is complete.  If you
have "validates_presence_of :foo", when :foo isn''t going to
be filled
out until some later page in your multi-page-wizard form, you CAN''T
save the model using AR before that page.


-- 
The major cause of problems are solutions. -- Eric Severeid

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

Not true. Validations are optional. You can save without validating, or you
can validate conditionally.  From the API:

validates_presence_of :foo, :if => Proc.new { |user| user.signup_step > 2
})

Validations have default behaviors, but that does not mean that you cannot
do more.  One might consider a different approach to modeling records for
multi-step processes. Just don''t let the way you think Rails works
dictate
how you model your application.



On 9/11/06, Michael Campbell
<michael.campbell-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
>
>
> Because validations on models assume the model is complete.  If you
> have "validates_presence_of :foo", when :foo isn''t going
to be filled
> out until some later page in your multi-page-wizard form, you
CAN''T
> save the model using AR before that page.
>
>

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

On 9/11/06, Brian Hogan <bphogan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Not true. Validations are optional. You can save without validating, or you
> can validate conditionally.  From the API:
>
> validates_presence_of :foo, :if => Proc.new { |user| user.signup_step
> 2 })
>
> Validations have default behaviors, but that does not mean that you cannot
> do more.  One might consider a different approach to modeling records for
> multi-step processes. Just don''t let the way you think Rails works
dictate
> how you model your application.

Fair enough; I hadn''t looked at them closely enough to have seen that.
 Thanks for that information, Brian.

Michael

-- 
At times one remains faithful to a cause only because its opponents do
not cease to be insipid. -- Friedrich Nietzsche

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

On 9/11/06, Brian Hogan <bphogan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Not true. Validations are optional. You can save without validating, or you
> can validate conditionally.  From the API:
>
> validates_presence_of :foo, :if => Proc.new { |user| user.signup_step
> 2 })
The more I think about this, the less I like it.  What if my model
participates in a number of different flows/wizards?  I''ll need to
have a Proc that tests 1 of n conditions?  No thanks.
I want to be able to tell /save/ to validate or not, not the model.
This way ties the model to the controller.

I guess I can have an attribute on the model that determines if
validation should occur, and set that before calling save, but that
feels... wrong.

I''m probably missing something basic here; what is it?

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

Michael Campbell wrote:
> I''m probably missing something basic here; what is it?
Your model is trying to do two things at once. You have a completed
script and a script. Those are two different states of a model object,
and the model should reflect that - two model classes and an
inheritance hierarchy.

NeilW


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

On 9/12/06, NeilW <aldursys-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
>
> Michael Campbell wrote:
> > I''m probably missing something basic here; what is it?
>
> Your model is trying to do two things at once. You have a completed
> script and a script. Those are two different states of a model object,
> and the model should reflect that - two model classes and an
> inheritance hierarchy.
Interesting; I''ll ponder that and see if it fits better what
I''m
doing.  Thanks for that insight, Neil.

Michael

-- 
If the code and the comments disagree, then both are probably wrong.
--Norm Schryer

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

I did this once using javascript and partials. When step 1 was finished and
someone pressed next I just hid the step 1 DIV and showed step 2. That way
when all the steps are done and Finish is pressed all the form data is
submitted at once although it''s DIV container is hidden.

-- 
--------------
Jon Gretar Borgthorsson
http://www.jongretar.net/


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

There''s a really neat side-effect of this approach....
If you placed the "go to step 2" button on the page using JS, then
users
without JS would still be able to use the wizard... though it would appear
as one big long form.

I''ve used that approach many times.

On 9/12/06, Jon Gretar Borgthorsson
<jon.borgthorsson-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
> I did this once using javascript and partials. When step 1 was finished
> and someone pressed next I just hid the step 1 DIV and showed step 2. That
> way when all the steps are done and Finish is pressed all the form data is
> submitted at once although it''s DIV container is hidden.
>
> --
> --------------
> Jon Gretar Borgthorsson
> http://www.jongretar.net/
>
> >
>

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

On 9/12/06, Brian Hogan <bphogan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
> There''s a really neat side-effect of this approach....
> If you placed the "go to step 2" button on the page using JS,
then users
> without JS would still be able to use the wizard... though it would appear
> as one big long form.
>
Sure. Although like I used it it would need some altering to work without
JS. I used partials alongside it. For example in this registration page I
used you entered requested username and email and before hiding the DIV it
checked if that username was taken and only displayed the next step after
that validation. Using this method also allowed me to minimize the amount of
actions I created in the controller as I prefer creating as few of those as
humanly possible. Using this method I got away with creating just one
"create" controller that sensed between PUT and POST and did some
in-form
validation using AJAX and a partial. It''s a little hassle to get going
in
the beginning but the code looked so much better.


-- 
--------------
Jon Gretar Borgthorsson
http://www.jongretar.net/


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---