On 20 April 2010 16:03, RichardOnRails <[email protected]> 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 at http://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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
