Michael Schuerig wrote: [...] >> What's the point of helper "polymorphism"? I'm having trouble coming >> up with a good use case for it. > > format_value, cancel_link are just two examples where generic names are > perfectly understandable within a context, although they may need to do > different things depending on context.
Does cancel_link need to do different things depending on context? If so, what? > >> meaningful to_s. Complex helpers should probably be made into >> partials. There's a fairly narrow band in between where helpers are >> really the best solution. >> >> Or maybe I don't understand what helpers are good for. Can you give >> me an example of what you think an appropriate helper method is? > > Say you an overview page where you want to consistently display numeric > or monetary values with a specific precision (or format in general). > Instead of sprinkling the view with > > <%= number_to_currency foo.amount, :precision => 0 %> > <%= number_to_currency bar.amount, :precision => 0 %> > ... > > you'd better define a suitable helper method: > > <%= format_money foo.amount %> > <%= format_money bar.amount %> > ... > > Then, in case you change your mind about how things ought to look, > there's only one place to change. And, besides, the helper methods name > can be used to convey some semantics. > > Now consider you have a more detailed view of similar information where > values are shown with full precision. There you could still use > format_money, but with a suitable implementation. I agree that the second option is better than the first, but I think they're both kind of bad. This is putting too much logic in the view IMHO (although I admit I sometimes do it anyway, until I refactor. :) ). What I would do instead is make foo.amount and bar.amount Money objects (using composed_of if ActiveRecord is involved). Then define Money#to_s, and the view will simply be <%= foo.amount %> <%= bar.amount %> I don't see any need for a helper here. Am I missing something? > > Before you ask, I don't like things like format_foo_bar_baz_money at > all. I don't want this kind of forced disambiguation, because I don't > want to be overly specific. It's up to the context what format_money is > supposed to mean. I'm not sure what that technique would even be, so don't worry -- I wasn't thinking of it! :) > Nicely, this even works with partials as they use just > those helper methods which are available in the given context. True. But that's only an issue if partials are shared between controllers. In my applications, I find that that does not happen often, but YMMV. > > Michael > > -- > Michael Schuerig > mailto:mich...@schuerig.de > http://www.schuerig.de/michael/ Best, -- Marnen Laibow-Koser http://www.marnen.org mar...@marnen.org -- Posted via http://www.ruby-forum.com/. -- 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-t...@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
