Hi, When you call a dynamic finder action (in your case find_by_ip), the ruby method_missing function is called. This magic functions takes the function you requested and creates it, which causes your function to be overwritten in favor of the created function. When you reload!, your model gets loaded again, and the created function is overwritten again. This isn't to be expected ofcourse.
Could you file a bug about this on http://dev.rubyonrails.com ? Regards, DefV On 16 Jan 2008, at 16:26, Carr0t wrote: > > As suggested in my thread in Ruby On Rails: Talk (http:// > groups.google.com/group/rubyonrails-talk/browse_thread/thread/ > 66ae64e6581a3896) i'm posting an issue i'm having with Rails 2.0 and > overloading find_by methods here. Hoepfully someone can either suggest > what I am doing wrong and should be doing instead to get this working, > or tell me where to submit a bug report so this can get fixed if it is > not desired behaviour: > > This came up when I migrated from rails 1.2.3 to 2.0.2. Previously, my > code was working fine. I am using > a mysql backend database, in which I am storing IPv4 addresses as 32 > bit unsigned integers. Of course, I don't want my users to have to > enter the IP they are searching for in this fashion, nor do I want to > have to make the conversion myself every time I call the find_by_ip > function or find_or_create_by_ip function for the model, so I have > overloaded those two functions. find_by_ip now reads as follows: > > def self.find_by_ip(ip) > super(NetAddr::CIDR.create(ip).to_i) > end > > This works, the first time Ip.find_by_ip(address) is called (this test > done in script/console): > >>> ip = Ip.find_by_ip("10.21.1.8") > => #<Ip id: 13, ip: 169148680> > > However any subsequent calls to find_by_ip just return nil, even for > the same IP address, until the environment is reloaded: > >>> reload! > Reloading... > => true >>> ip = Ip.find_by_ip("10.21.1.8") > => #<Ip id: 13, ip: 169148680> >>> ip = Ip.find_by_ip("10.21.1.8") > => nil > > If I add some puts statements in my overloaded find_by_ip, they never > get printed out after the first call to it has been done. Equally, if > I call find_by_ip with a 32 bit int form of an IPv4 address it works > reliably: > > def self.find_by_ip(ip) > puts "Testing\n" > super(NetAddr::CIDR.create(ip).to_i) > end > > ?> reload! > Reloading... > => true >>> ip = Ip.find_by_ip("10.21.1.8") > Testing > => #<Ip id: 13, ip: 169148680> >>> ip = Ip.find_by_ip("10.21.1.8") > => nil >>> ip = Ip.find_by_ip(169148680) > => #<Ip id: 13, ip: 169148680> > > It is as if, after the first call to my overloaded find_by_ip, rails > decides to ignore my overloaded function and go straight to the base > functionality it has for creating find_by functions. The suggestion > was that, in Rails 2.0, instead of calling the method_missing function > every time I call super() from within a find_by_function (as there is > no specific find_by function of that name in ActiveRecord::Base), it > instead creates the find_by_ip function, which overwrites my one, and > subsequent calls hit that and thus don't get the IP address converted > to an int, and thus don't find any matching record in the database. I > am assuming this change was made for speed, as as long as you are not > overloading a find_by function it will be faster if the function is > pre-generated instead of having to be created every time it is called, > but what can I do to fix this? Is the best fix to call my 'overload' > function get_by_ip (or similar), so that the created find_by_ip > function doesn't have a namespace conflict, and then call > self.find_by_ip from within that once I have got my IP in numerical > format? This does work, but does mean that my code is sometimes using > find_by and sometimes using get_by (or whatever), which makes it > harder for anyone following to debug as it is not consistent. > > Thanks > > Dan Meyers > Network Support, Lancaster University > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" 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-core?hl=en -~----------~----~----~----~------~----~------~--~---
