On Dec 21, 6:12 pm, Dan Brooking <dmbrook...@gmail.com> wrote:
> class Page < ActiveRecord::Base > attr_accessible :url, :title > > after_initialize :parse_page_params > > def parse_page_params > @title = "test" > end > > and this wasn't working... I understand what you said above about the > instance variables, methods, initializing, etc.. but still a little unclear > about why that code doesn't work as I'm setting it. Is it because Rails > uses the method name of title which hasn't been initailized in my > assignment above? > Because rails doesn't use individual instance variables to store your attributes (whether they've been marked as attr_accessible makes no difference) title = "foo" Doesn't work because ruby assumes that you want to assign to the local variable called title. Doing self.title = makes it clear that you want to call the title= accessor Fred > On Fri, Dec 21, 2012 at 12:43 PM, Walter Lee Davis <wa...@wdstudio.com>wrote: > > > > > > > > > > > On Dec 21, 2012, at 12:37 PM, Dan Brooking wrote: > > > > I posted a previous message about overriding initialize... because I was > > having issues setting some of the parameters. I have a Page model that has: > > > > attr_accessible :url, :title, :doc, :domain > > > > and it's called via: > > > > Page.new(:url => 'http://www.yahoo.com') > > > > Since I'm only passing in the url to new, I needed to set the other > > parameters. I was trying to do this via an after_initialize callback which > > wasn't working so tried overriding initialize... still not working. > > > > What I found out was that in my after_initialize, I was referring to > > title as @title which is why it was not working. I switched it to > > self.title and it works fine. > > > > My question is - why? > > > @title is an instance variable. Until you set it, it doesn't exist. Having > > a method on the model called title (or an accessor, or some other Rails > > magick) does not instantiate that method's return until and unless you ask > > for it by calling the method. Calling self.method_name just makes it clear > > which same-named method you really mean. Self is implied much of the time, > > but when you have all the many method_missing options available, it might > > not be the first one such that gets called. > > > Walter > > > > -- > > > 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-talk@googlegroups.com. > > > To unsubscribe from this group, send email to > > rubyonrails-talk+unsubscr...@googlegroups.com. > > > To view this discussion on the web visit > >https://groups.google.com/d/msg/rubyonrails-talk/-/-ncNakybQ-cJ. > > > For more options, visithttps://groups.google.com/groups/opt_out. > > > -- > > 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-talk@googlegroups.com. > > To unsubscribe from this group, send email to > > rubyonrails-talk+unsubscr...@googlegroups.com. > > For more options, visithttps://groups.google.com/groups/opt_out. -- 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-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
