On 24 April 2010 22:53, RichardOnRails <richarddummymailbox58...@uscomputergurus.com> wrote: > Hi Colin, > > I had to work on adding authenticated users to my app, so I had to > back-burner the conditional-link issue. I nevertheless would like to > keep trying to learn how to do this. Maybe CSS is the way to make the > link switch between visible or not depending on context. (Just my > inspiration at the moment.) > > Also, you mentioned that I needed have my switch initialized to > false, because nil will result in the same thing, so I just > commented it out in VendorController. Seems to clear up one problem. > >> Your first attempt just above is already a class variable, as it >> starts with @ so I don't follow you here.
Yes you are right of course, forgot to engage brain. There is no need for a class variable, an instance variable is what you want. Colin > > I think @xxx defines an instance variables while @@xxx defines a class > variable in Ruby. That's what my Ruby books tell me, as does > http://www.rubyist.net/~slagell/ruby/instancevars.html. > > It's nice that we got a couple of other respondents. Maybe we'll get > this resolved shortly. > > Best wishes, > Richard > > > On Apr 20, 1:11 pm, Colin Law <clan...@googlemail.com> wrote: >> On 20 April 2010 16:03, RichardOnRails >> >> >> >> <richarddummymailbox58...@uscomputergurus.com> wrote: >> > Hi Colin, >> >> >>> The following in app\views\vendors\show.html.erb works perfectly >> >>> <%= link_to 'New Expense', '/expenses/new' %> >> >> >>> I have the following in app\controllers\vendors_controller.rb >> >>> class VendorsController < ApplicationController >> >>> @show_new_expense_page = true >> >>> [snip[ >> >> >>> I now have in app\views\vendors\show.html.erb >> >>> <%= link_to 'New Expense', '/expenses/new' if @show_new_expense_page %> >> >>> The foregoing link fails to be displayed >> >> >> I guess in this case that @showExpenseNew is not actually true as you >> >> think it is. >> > You are so right!! It is nil >> >> >> look athttp://guides.rubyonrails.org/ >> > Excellent guidance; it's excellent >> >> >> My favorite is to use ruby-debug >> > I did that. It took me days to get working. I won't bore you with my >> > travails. But knew I needed to be able to debug but I didn't want to >> > detour from getting version 1 of my app completed. But your >> > suggestion persuaded me otherwise. >> >> > My goal is to have a variable that is persistent and which: >> > 1. Is defined somewhere and initialized to false >> >> You don't need to define it and set it to false, the code >> if variable >> is ok to use if variable is not defined - that is the same as false. >> So you only need to set it to true where you want it true. >> >> > 2. Is set to true in app\views\expenses\new.html.erb when the <%= >> > link_to 'New Vendor' ... is clicked >> >> Sounds good >> >> > 3. Is referenced in app\views\vendors\show.html.erb as a condition for >> > whether to display some link >> >> Also sounds good >> >> >> >> > My current guess is to use a session variable, which I've got a lot >> > of hope for. If that doesn't work, I'll start a new thread. >> >> There should not be any need for a session variable, just set it in >> the controller and test it in the view. >> >> >> >> > Best wishes, >> > Richard >> >> > BTW, some of my failures are: >> > My first attempt to see whether a shared value would work with >> > @show_new_expense_page = true in app\controllers >> > \vendors_controller.rb >> > failed in app\views\vendors\show.html.erb >> > because @show_new_expense_page was nil, >> >> Why is it nil if you are setting in in the controller? Are you sure >> it is executing that line in the controller. Break there with >> ruby-debug and check. >> >> > which ruby_debug demonstated for me, thanks to you. >> >> > My second attempt changed to a class variable @show_new_expense_page >> > in both places, which resulted in a syntax error. >> >> Your first attempt just above is already a class variable, as it >> starts with @ so I don't follow you here. >> >> >> >> > My third attemp was to initialize @show_new_expense_page in >> > app\controllers\application_controller.rb >> >> No need for it in application_controller, only things that all >> controllers need go here. >> >> Colin >> >> > which led to NameError in Vendors#show >> > uninitialized class variable @@show_new_expense_page in >> > ActionView::Base::CompiledTemplates >> >> -- >> 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-t...@googlegroups.com. >> To unsubscribe from this group, send email to >> rubyonrails-talk+unsubscr...@googlegroups.com. >> For more options, visit this group >> athttp://groups.google.com/group/rubyonrails-talk?hl=en. > > -- > 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-t...@googlegroups.com. > To unsubscribe from this group, send email to > rubyonrails-talk+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/rubyonrails-talk?hl=en. > > -- 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-t...@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
