# Need help with model logic **URL:** \ **Category:** Rails\ **Created:** [September 1, 2010, 6:59pm UTC](https://www.ruby-forum.com/t/need-help-with-model-logic/194258 "2010-09-01T18:59:23Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![beachguy82](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/9dc877/32.png) [@beachguy82](https://www.ruby-forum.com/u/beachguy82)\ **Post date:** [September 1, 2010, 6:59pm UTC](https://www.ruby-forum.com/t/need-help-with-model-logic/194258/1 "2010-09-01T18:59:23Z")
Hi all - Ruby 1.8.7 / Rails 2.3.5 Schedule model: course\_id, starts\_at, ends\_at, capacity has\_many :requests Request model: user\_id, schedule\_id, state\_id belongs\_to :schedule request.state\_id indicates whether the request has been approved. (state\_id = 2 = pending my approval, state\_id = 3 = approved) I want to list all requests pending my approval, along with the remaining seats available. def listPendingRequest @allRequests = Request.find(:all, :conditions =\> [“state\_id = ?”, 2]).each{ |request| @schedule = Schedule.find(:first, :conditions =\> [“id = ?”,request.schedule\_id]) @num = Request.find(:all, :conditions =\> [“state\_id = ? AND schedule\_id = ?”, ‘3’, @schedule.id]).nitems @remaining = @schedule.capacity - @num } @request = Array.new @allRequests.each do |r| if (r.state\_id == 2 and r.approver\_id == current\_user.id) @request \<\< r end end if @request.empty? flash.now[:alert] = “You have no pending requests to approve.” end end I currently have this method in my request controller, but I think it belongs in a model. I don’t know which model, though. Also, this method shows the remaining seats for the first schedule on all of the requests, regardless of which schedule is being requested. When I do a @schedule = Schedule.find(:all…), I get an error: “undefined method ‘capacity’ for Array”. What am I doing wrong? And where should I put the method? Thanks in advance for your help!! ---
**Author:** ![beachguy82](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/9dc877/32.png) [@beachguy82](https://www.ruby-forum.com/u/beachguy82)\ **Post date:** [September 1, 2010, 10:49pm UTC](https://www.ruby-forum.com/t/need-help-with-model-logic/194258/2 "2010-09-01T22:49:29Z")
On 1 September 2010 17:59, Charlie B99 [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hi all - > > Ruby 1.8.7 / Rails 2.3.5 I have not worked right through your code but have got some comments that may help (or not). > I want to list all requests pending my approval, along with the > remaining seats available. What is a seat? This is the first time you have mentioned it. > def listPendingRequest I would advise using the rails convention for naming things, so this would be list\_pending\_requests > @allRequests = Request.find(:all, :conditions =\> [“state\_id = ?”, > 2]).each{ > |request| > @schedule = Schedule.find(:first, :conditions =\> [“id = > ?”,request.schedule\_id]) If the above is finding the schedule for request you don’t need to do a find, just use @schedule = request.schedule. > @num = Request.find(:all, :conditions =\> [“state\_id = ? AND schedule\_id > = ?”, ‘3’, @schedule.id]).nitems Now that you have a schedule, the requests for that schedule are @schedule.requests, so you can do something like @num = @schedule.requests.find(:all, “state\_id = ?”, 3).count Unless you need @num to be an instance variable of whatever class this ends up in then just make it a simple variable - num Is there a reason why you are using nitems rather than count? > @remaining = @schedule.capacity - @num > } You have now dropped out of the block. Note that you overwrote @remaining each time round. so it will now have the value of the last time round. I am not sure that the block contents have achieved anything at all. > @request = Array.new If @request is going to contain a number of items call it @requests. > @allRequests.each do |r| > if (r.state\_id == 2 and r.approver\_id == current\_user.id) I am not sure what is going on here as I am running out of time. You have not told us the relationships between Request and User. If you find yourself using something.id then very often you just need to setup the relationships in the right way and you can do the same sort of thing as with schedules and requests above. So you may need something like User has\_many approved\_requests with approver\_id as the foreign key, then User.approved\_requests will give you the requests that user has approved. > belongs in a model. I don’t know which model, though. > I suspect that it may be User method as it returns his pending > requests, but maybe not. Also consider whether this is really the > functionality you want. Often when the return from a method is > defined as returns something along with something else (as you have > done here) you actually want two separate methods. So maybe one that > gives the users unnaproved requests (which would be a User method > probably, and may have involve no code if you get the relationships > right) and a separate one to return remaining seats available > (whatever that means). > Also, this method shows the remaining seats for the first schedule on > all of the requests, regardless of which schedule is being requested. > When I do a @schedule = Schedule.find(:all…), I get an error: > “undefined method ‘capacity’ for Array”. Does that only happen in the above code or do you mean that you just cannot do Schedule.find(:all)? If you can do a simple find all then gradually add bits to the working one till you get the problem. How can the method be showing anything if you get that error? Sorry I have probably not been able to give this the thought it deserves but maybe this will at least be of some help. Colin ---
**Author:** ![beachguy82](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/9dc877/32.png) [@beachguy82](https://www.ruby-forum.com/u/beachguy82)\ **Post date:** [September 2, 2010, 6:57pm UTC](https://www.ruby-forum.com/t/need-help-with-model-logic/194258/3 "2010-09-02T18:57:52Z")
On 2 September 2010 16:37, Charlie B99 [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Could you not top post please - insert your comments at the appropriate place in previous mail, it makes it easier to follow the thread, particularly for those that find this thread in the future. Thanks > Colin, thanks so much for all your input. As you can see, I’m just > muddling my way through all this, and all of your comments are very > helpful. I will go through them more when I get to the office… > > “remaining seats” = schedule.capacity - number of approved requests. > So, if a schedule has a capacity of 10, and 8 requests with state\_id = 3 > (approved), then there are 2 available slots before the capacity reaches > 0 and no more requests can be accepted. > > Can I do request.schedule as a find in 2.3.5 or is that a 3.0 feature? Most certainly you can. I think maybe you would benefit from reading the rails guides at [Ruby on Rails guides](http://guides.rubyonrails.org/v2.3.8/) Those will be ok for 2.3.5 (why are you not using the latest 2.3 I wonder?). Particularly Getting Started, ActiveRecord Associations, Routing, and Debugging. Colin ---
**Author:** ![beachguy82](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/9dc877/32.png) [@beachguy82](https://www.ruby-forum.com/u/beachguy82)\ **Post date:** [September 2, 2010, 5:37pm UTC](https://www.ruby-forum.com/t/need-help-with-model-logic/194258/4 "2010-09-02T17:37:40Z")
Colin, thanks so much for all your input. As you can see, I’m just muddling my way through all this, and all of your comments are very helpful. I will go through them more when I get to the office… “remaining seats” = schedule.capacity - number of approved requests. So, if a schedule has a capacity of 10, and 8 requests with state\_id = 3 (approved), then there are 2 available slots before the capacity reaches 0 and no more requests can be accepted. Can I do request.schedule as a find in 2.3.5 or is that a 3.0 feature? I used nitems because I didn’t know any better. 🙂 You’ve got me pointed in the right direction now - I’m new and messy, but I’m diggin it, so will keep pluggin away. Thanks again! Colin L. wrote: > On 1 September 2010 17:59, Charlie B99 [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Hi all - > > > > Ruby 1.8.7 / Rails 2.3.5 > > I have not worked right through your code but have got some comments > that may help (or not). > > > I want to list all requests pending my approval, along with the > > remaining seats available. > > What is a seat? This is the first time you have mentioned it. > > > def listPendingRequest > > I would advise using the rails convention for naming things, so this > would be list\_pending\_requests > > > @allRequests = Request.find(:all, :conditions =\> [“state\_id = ?”, > > 2]).each{ > > |request| > > @schedule = Schedule.find(:first, :conditions =\> [“id = > > ?”,request.schedule\_id]) > > If the above is finding the schedule for request you don’t need to do > a find, just use > @schedule = request.schedule. > > > @num = Request.find(:all, :conditions =\> [“state\_id = ? AND schedule\_id > > = ?”, ‘3’, @schedule.id]).nitems > > Now that you have a schedule, the requests for that schedule are > @schedule.requests, so you can do something like > @num = @schedule.requests.find(:all, “state\_id = ?”, 3).count > > Unless you need @num to be an instance variable of whatever class this > ends up in then just make it a simple variable - num > > Is there a reason why you are using nitems rather than count? > > > @remaining = @schedule.capacity - @num > > } > > You have now dropped out of the block. Note that you overwrote > @remaining each time round. so it will now have the value of the last > time round. I am not sure that the block contents have achieved > anything at all. > > > @request = Array.new > > If @request is going to contain a number of items call it @requests. > > > @allRequests.each do |r| > > if (r.state\_id == 2 and r.approver\_id == current\_user.id) > > I am not sure what is going on here as I am running out of time. You > have not told us the relationships between Request and User. If you > find yourself using something.id then very often you just need to > setup the relationships in the right way and you can do the same sort > of thing as with schedules and requests above. So you may need > something like User has\_many approved\_requests with approver\_id as the > foreign key, then User.approved\_requests will give you the requests > that user has approved. > > > belongs in a model. �I don’t know which model, though. > > I suspect that it may be User method as it returns his pending > > requests, but maybe not. Also consider whether this is really the > > functionality you want. Often when the return from a method is > > defined as returns something along with something else (as you have > > done here) you actually want two separate methods. So maybe one that > > gives the users unnaproved requests (which would be a User method > > probably, and may have involve no code if you get the relationships > > right) and a separate one to return remaining seats available > > (whatever that means). > > > Also, this method shows the remaining seats for the first schedule on > > all of the requests, regardless of which schedule is being requested. > > When I do a @schedule = Schedule.find(:all…), I get an error: > > “undefined method ‘capacity’ for Array”. > > Does that only happen in the above code or do you mean that you just > cannot do Schedule.find(:all)? If you can do a simple find all then > gradually add bits to the working one till you get the problem. How > can the method be showing anything if you get that error? > > Sorry I have probably not been able to give this the thought it > deserves but maybe this will at least be of some help. > > Colin