> We already have Object#present? :) True, but present? is just the inverse of blank?. What we've found very useful is to have a method that treats blank parameters the same as missing ones, and allows chaining.
Check out the example: state = params[:state] unless params[:state].blank? country = params[:country] unless params[:country].blank? region = state || country || 'US' Rewriting with present? isn't any more expressive: state = params[:state] if params[:state].present? country = params[:country] if params[:country].present? region = state || country || 'US' But nonblank? makes it more concise and expressive IMO: region = params[:state].nonblank? || params[:country].nonblank? || 'US' We've been using it this way for the last year and it really has cleaned up a lot of code. More importantly it has become a reflex to use it inline--as shown above--that has helped us avoid bugs where we might think a parameter was present but really it was just there with an empty value. I suppose we could keep the method name present? but switch its behavior to match what's proposed here for nonblank?. But that contract change could break someone's code who was depending on a boolean being returned. Also I prefer that nonblank? has a name that parallels nonzero? from Ruby. I like the symmetrical pair of nonzero? and nonblank? because they map values (0, empty/blank string respectively) to nil that are typically equivalent to not being present at all. Other languages like Python found it convenient to have 0 and empty string treated as false for just this reason I think. -Colin On Dec 27, 5:37 am, Pratik <[email protected]> wrote: > We already have Object#present? :) > > > > > > On Sun, Dec 27, 2009 at 7:49 AM, ColinDKelley <[email protected]> wrote: > > All, > > > I'd like to propose the Object#nonblank? in ActiveSupport, layered > > over the blank? method. This has been working well for us in the past > > year and hopefully others will find it useful enough to include in > > core. > > > It is analogous to Ruby's Numeric#nonzero? method: it either returns > > the object itself (if not blank) or nil (if blank). This makes it easy > > to treat blank parameters the same as missing ones, and allows > > chaining: > > > For example, this: > > > state = params[:state] unless params[:state].blank? > > country = params[:country] unless params[:country].blank? > > region = state || country || 'US' > > > becomes: > > > region = params[:state].nonblank? || params[:country].nonblank? || > > 'US' > > > The ticket is here: > > >https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/3... > > > along with a patch that includes full documentation and tests. > > > -- > > > 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 > > athttp://groups.google.com/group/rubyonrails-core?hl=en. > > -- > Cheers! > - Pratikhttp://m.onkey.org|http://twitter.com/lifo -- 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.
