I don't have the answer to your question, but I wouldn't say `send` is inherently evil. It all depends on the source of the data. If your `scope` argument is some meta-programming (i.e. the value is defined by the programmer) then it can be safe to use. If it is user input then obviously you would want to whitelist against the scopes you have defined.
Also remember scopes are just a class method that returns an ActiveRecord::Relation. I.E. you may have a "scope" that wouldn't be on any Rails internal data structure if the `scope` method was not used to define it. Eric On Sunday, March 17, 2019 at 3:56:05 PM UTC-4, Walter Lee Davis wrote: > > I want to (in a metaprogramming context) invoke a scope on an ActiveRecord > based model. I know the name of the scope, but I don't want to use `send` > to do this, because send can be evil. I know that ActiveRecord defines a > class method named scope that gathers up these scopes somewhere internally, > but I can't figure out where that is, or how you can pick one out of the > stack to execute. > > What is the best equivalent to this (completely made-up example): > > def call_scope(model, scope = 'all') > model.send scope.to_sym > end > > The key feature is that we late-evaluate which model and which scope, so > it can be used inside an enumerator, and doesn't rely on knowing the exact > parties in play. > > Would this be a good place for class_eval? (I just tried that, and it > works) > > def call_scope(model, scope = 'all') > model.class_eval scope.to_s > end > > Is there something more Rails-like I could/should use? > > Am I wrong about send? > > Thanks in advance, > > Walter -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/8c70025c-91e9-45d1-b365-effdab19fbb3%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
