Re: Coding Guidelines: Instance variables in views

On Fri, Aug 17, 2012 at 10:52:46AM +0200, Jirka Tomasek wrote: > > I don't like the sentence "Don't use it for passing variables to > view. Never." which is actually one of the first things that any > Rails book teaches you. Yes, that was the main source of my confusion. > I agree that we should try to reduce using > instance variables in controllers where possible to avoid cluttering > controllers with them. As someone mentioned in another reply here, there are uses where you really need them -- e.g., before_filters. Of course we should be careful to not use instance variables where there's no need for them; sometimes we'll mistakenly use an instance variable just within the scope of a method, for example. > The blog post you sent points out the reusability of partials so > passing the variables as locals helps avoid requiring use of eg. > @post in all partials instances. Imho it depends on the desired use > of the partial. > > We have discussed with Imre the alternative way to pass variables > from controller's action to view. It can be done similar way as with > partials: > > ...someactioncode... > render :action => :index, :locals => {:post => post} > end > > > but I have never seen this used anywhere in controller and I assume > this is not the "Rails way". Yes, this feels pretty weird to me. That whole line should be unnecessary -- we're overriding the "Rails magic" to explicitly perform the default behavior, except referencing the variable as a local one. If anything, this seems _more_ error-prone to me than relying on instance variables. -- Matt