On 21 April 2010 05:46, Bob Smith <[email protected]> wrote: > Try using params instead of variables. The variables lose scope when > changing between views/controllers and once that happens, the value > becomes nil. Instead of > @show_new_expanse_page = true try > params['new_expense_page'] = true > > and the value will persist until used. the test for this would be > changed from > > <%= link_to 'New Expense', '/expenses/new' if @show_new_expense_page > %> to > <%= link_to 'New Expense', '/expenses/new' if > params['show_new_expense_page'] %>
Bob, I don't understand, a variable @show_new_expense_page set in the controller will be available in the view. Colin > > > Good luck > > Bob > > On Apr 20, 1:11 pm, Colin Law <[email protected]> wrote: >> 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 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 [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> 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 [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. > > -- 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.
