On 21 March 2018 at 03:12, dragoncity <dragoncitybr...@gmail.com> wrote: > Hello, I'm just getting into Pharo, and am trying to > do the example 'tutorial' UI programs in chapter 2 of The Spec UI Framework > book. I have a special interest in end user GUI interfaces for programs. I > enter the first example code as written and the methods are all accepted > without errors. And yes, I did generate the accessors. > > However , on attempting to execute the code at the bottom of page 6 from the > latest Spec UI Framework book, > > > | ui | > > ui := CustomerSatisfaction newopenWithSpec. > > ui close. > > > > this error message appears, no UI image appears of course. > > "SubclassResponsibility:CustomerSatisfaction class had the subclass > responsibility to implement #defaultSpec" > > ====== > > Not only don't I understand the message, but it implies I have to write > something called #defaultSpec !, which is not mentioned in the tutorial.
CustomerSatisfaction is a subclass of ComposableModel (ComposablePresenter in Pharo 7). If you have a look at the implementation of #defaultSpec in ComposableModel or ComposablePresenter (depending on which version of Pharo you are using) it says that it is up to subclasses to implement the method (#subclassResponsibility). Since you haven't defined it (yet), the call to #defaultSpec uses the inherited definition from ComposableModel, which raises the error you are seeing. CustomerSatisfaction class>>defaultSpec is on page 6 of my version of the booklet, dated Feb 6, 2107. Cheers, Alistair
