# ROR questions **URL:** \ **Category:** Rails\ **Created:** [July 11, 2006, 12:29am UTC](https://www.ruby-forum.com/t/ror-questions/97871 "2006-07-11T00:29:10Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 12:29am UTC](https://www.ruby-forum.com/t/ror-questions/97871/1 "2006-07-11T00:29:10Z")
Hi, I’m a Ruby on Rails newbie. I’ve been tasked with building our office’s first ROR application, and I am the only one working on it, so I am muddling through with a couple of books… Moving along slowly but need some discussion time with some people who KNOW it and can maybe offer some answers to questions I haven’t found in my books. First - what is the fundamental difference between “render” and “redirect\_to” when working with .rhtml forms in the Controller? When is it appropriate to use these? Second - Why do I sometimes have to use a while loop to access my queried data in the .rhtml form? Example: Controller-Edit Method @edit = Cause.find(:all, :conditions =\> “case\_id = ‘#{@caseid}’”) View-Edit.rhtml ## Editing Case \<%= @edit.case\_id %\> This method of data retrieval has worked for me in other similar forms, and I can’t figure out why it won’t work here. The error it gives is that case\_id is not a valid method, but it is a valid field in the table, so should work. (case\_id is the foreign key for the table) However, if I put the data retrieval inside a while loop, it displays the data, but gives me a routing error when I try to update. I have other questions as well, but I guess I’ll start here. ANY AND ALL tips, advice, etc. would be greatly appreciated!! Thank you, Ali Williams Systems Developer II Washoe County IT 775 328-3720 Ali Williams Systems Developer II Washoe County IT 775 328-3720 ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 12:48am UTC](https://www.ruby-forum.com/t/ror-questions/97871/2 "2006-07-11T00:48:57Z")
> I’m a Ruby on Rails newbie. I’ve been tasked with building our office’s first ROR application, and I am the only one working on it, so I am muddling through with a couple of books… Moving along slowly but need some discussion time with some people who KNOW it and can maybe offer some answers to questions I haven’t found in my books. Grats, welcome to the wonderful world of Ralis. We’re all mad here. Or something like that; I can’t pretend to be \_why, he really is mad. > First - what is the fundamental difference between “render” and “redirect\_to” when working with .rhtml forms in the Controller? When is it appropriate to use these? As I understand it redirect\_to issues a 302 and redirects the browser to a page, render on the other hand just renders whatever you say to render without the redirect. In my use I rarely use render directly (it’s the default call for every controller action so I actually use it all the time). The only time I call it explicitly is when I’m not sure if there’s going to be a redirect\_to between me and the end of a function. So, essentially never unless I’ve not been writing tests for some reason. Just remember that `render function_name` is the default last call made by an action that hasn’t been redirected and you won’t have to worry about the difference. > However, if I put the data retrieval inside a while loop, it displays the data, but gives me a routing error when I try to update. > This is a bit of a trick question without some more info, so I’ll try > to answer all instances. 1. If you’re using belongs\_to/has\_one/has\_many/habtm then you should just be doing @edit.case.id 2. @edit may be a hash, you’re using find(:all) which could return more than one object. You can find out by using the breakpointer or by having `<%= debug @edit %>` somewhere on the rhtml page. 3. @edit.case may be nil, in which case it would throw an error. If you send us the error messages we may be able to get to the root of your particular evil. Once again, welcome to the fold. If you aren’t already testing you should be; it’s not just for professionals anymore. 🙂 Ta, Chuck V. ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 1:04am UTC](https://www.ruby-forum.com/t/ror-questions/97871/3 "2006-07-11T01:04:46Z")
On Monday, July 10, 2006, at 3:46 PM, Chuck V. wrote: > > “redirect\_to” when working with .rhtml forms in the Controller? When > > > View-Edit.rhtml > > This is a bit of a trick question without some more info, so I’ll try > > your particular evil. > > Once again, welcome to the fold. If you aren’t already testing you > should be; it’s not just for professionals anymore. 🙂 > > Ta, > Chuck V. > > * * * > > Rails mailing list > removed\_email\_address@domain.invalid > [http://lists.rubyonrails.org/mailman/listinfo/rails](http://lists.rubyonrails.org/mailman/listinfo/rails) I’d also be careful about using ‘case’ as a model name. It’s also a ruby keyword, so it could cause all sorts of problems if you aren’t careful. \_Kevin ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 8:13am UTC](https://www.ruby-forum.com/t/ror-questions/97871/4 "2006-07-11T08:13:41Z")
ali wrote: However, when I try to update, I get routing error "Recognition failed for “/update/24” - which is the correct id for the row I’m trying to update, so I don’t see where it’s getting screwed up? * * * can you put your update action from the controller here? i suspect that could be a part of the problem - - if the id (24) is the correct id you want to update in a habtam/has\_many/has\_somethign/etc relashinship for a certain table, and you are looking it up in a different table (i.e, the second party in the relashinship), that may cause problems. also, not less importantly, i strongly suggest you use \<%= start\_form\_tag :action =\> ‘update’ %\> rather than ...good plausible reason for the routing error you're getting ((Recognition failed for "/update/24)) if the action itself does exist in the controller... anyway, i hope it helps, and welcome to ror, shai ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 6:25pm UTC](https://www.ruby-forum.com/t/ror-questions/97871/5 "2006-07-11T18:25:31Z")
shai \ writes: > could be a part of the problem - - if the id (24) is the correct id you > > anyway, i hope it helps, > and welcome to ror, > > shai ThankYou ThankYou for all your suggestions - they have been very helpful! My next question is regarding sessions. Does ROR support session variables, or just sessions in general? I haven’t found anything on session variables specifically. In my “layout”, I have created a navigation bar that will be displayed on every page. I want each link to link to the “show” method for that controller, and pass in the case\_id. Users work with the same case\_id until the brower is closed, or they do a search for a different case, so the case\_id needs to stay set and displayed on every form. Should I use a session for this, or attempt to keep passing through GET for every form action? Thanks again! ~Ali ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 1:17am UTC](https://www.ruby-forum.com/t/ror-questions/97871/6 "2006-07-11T01:17:11Z")
Williams, Ali \ writes: > Hi, > > I’m a Ruby on Rails newbie. I’ve been tasked with building our office’s first > ROR application, and I am the > only one working on it, so I am muddling through with a couple of books… > Moving along slowly but need > some discussion time with some people who KNOW it and can maybe offer some > answers to questions I haven’t > found in my books. > > First - what is the fundamental difference between “render” and “redirect\_to” > when working with .rhtml > forms in the Controller? When is it appropriate to use these? > > Second - Why do I sometimes have to use a while loop to access my queried > data in the .rhtml form? Example: > > Controller-Edit Method > edit = Cause.find(:all, :conditions =\> “case\_id = ‘#{ caseid}’”) > > View-Edit.rhtml > > ## Editing Case \<%= edit.case\_id %\> > > This method of data retrieval has worked for me in other similar forms, and I > can’t figure out why it won’t > work here. The error it gives is that case\_id is not a valid method, but it > is a valid field in the table, so > should work. (case\_id is the foreign key for the table) > > However, if I put the data retrieval inside a while loop, it displays the > data, but gives me a routing error > when I try to update. > > I have other questions as well, but I guess I’ll start here. ANY AND ALL > tips, advice, etc. would be greatly appreciated!! > > Thank you, > > Ali Williams > Systems Developer II > Washoe County IT > 775 328-3720 Thanks for the cordial and speedy reply. It’s hard to find pleasant people to chat with in this realm. And plus you quoted my fave cartoon character, so I’ll be hanging around here! 😉 Ok, more specific code from Edit.rhtml: * * * \<% @edit.each do |edit| %\> ## Editing Case \<%= edit.case\_id %\> ### CAUSE INFORMATION ### \* Indicates required field ```
* CAUSE OF DEATH:
MANNER OF DEATH:
* PRIMARY(a):
``` \<% end %\> * * * As you can see, I’ve succumbed to putting my data retrieval in a while loop, so it now displays in the form correctly. However, when I try to update, I get routing error "Recognition failed for “/update/24” - which is the correct id for the row I’m trying to update, so I don’t see where it’s getting screwed up? The only thing I’m doing different from my other forms is that I’m calling the Show routine from a navigation bar, and it is handling the redirect based on whether the query finds anything in the table for the passed-in case\_id: def show ``` @caseid = @params['case_id'] @cause = Cause.find(:all, :conditions => "case_id = '#{@caseid}'") # if no Cause data for case_id, new; else, edit @len = @cause.length if @len == 0 redirect_to :action => 'new', :case_id => @caseid else redirect_to :action => 'edit', :case_id => @caseid end ``` end Other than that, it is setup just like my other forms that WORK. Frustration… ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 11:31pm UTC](https://www.ruby-forum.com/t/ror-questions/97871/7 "2006-07-11T23:31:11Z")
On 7/11/06, Isak H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > browser. It’s not a foolproof method of preventing the same action to be called twice, however… Isak ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 11, 2006, 10:47pm UTC](https://www.ruby-forum.com/t/ror-questions/97871/8 "2006-07-11T22:47:16Z")
On 7/11/06, Williams, Ali [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hi, > > I’m a Ruby on Rails newbie. I’ve been tasked with building our office’s first ROR application, and I am the only one working on it, so I am muddling through with a couple of books… Moving along slowly but need some discussion time with some people who KNOW it and can maybe offer some answers to questions I haven’t found in my books. > > First - what is the fundamental difference between “render” and “redirect\_to” when working with .rhtml forms in the Controller? When is it appropriate to use these? “redirect\_to” is generally used after a post or some other action you don’t want repeated if the user should refresh the page in their browser. Isak ---
**Author:** ![WilliamsS\_Ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ce7236/32.png) [@WilliamsS\_Ali](https://www.ruby-forum.com/u/WilliamsS_Ali)\ **Post date:** [July 15, 2006, 12:47am UTC](https://www.ruby-forum.com/t/ror-questions/97871/9 "2006-07-15T00:47:49Z")
> > ((Recognition failed for "/update/24)) if the action itself does exist > > My next question is regarding sessions. Does ROR support session variables, or > just sessions in general? I haven’t found anything on session variables > specifically. In my “layout”, I have created a navigation bar that will be > displayed on every page. I want each link to link to the “show” method for that > controller, and pass in the case\_id. Users work with the same case\_id until the > brower is closed, or they do a search for a different case, so the case\_id needs > to stay set and displayed on every form. Should I use a session for this, or > attempt to keep passing through GET for every form action? Hehe, I would say that a variable that exists for the duration of a users session should probably be a session var. But that’s just me, I could be wrong. 😛 @session[:monkey] = “I like monkeys… Maybe too much.” or @flash[:gordon] = :space\_ship\_captain which will persist for one redirection (most useful for doing flash[:notice] or flash[:error] when an action triggers an error and then redirects to some other page) Have you picked up Agile Web D. With Rails yet? It’s pretty important, most of these questions have been answered in much more detail in that book (and the authors are good kids). Cheers, Chuck V.