Unable to execute example code from "The Spec UI Framework" Book

> 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.

> On 21/03/18 17:55, Alistair Grant wrote:
>>
>> On 21 March 2018 at 03:12, dragoncity <[hidden email]> 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
>>
>>
>
> --
> Cheers,
> Brett
>

> On 21 March 2018 at 08:37, dragoncity <[hidden email]> wrote:
>> I had already  defined & accepted defaultSpec , as per page 6.
>>
>> Attached is my CustomerSatisfaction.st file :  I assume Pharo will suck it
>> back in !
> You've defined this as an instance method, not a class method.
>
> If what I've said doesn't make sense, let us know and we can point you
> to a description (which I don't have handy).  One tip: Assuming you're
> using Pharo 6, in the System Browser, roughly in the middle is a
> "Class" button.  Pressing that will show you the class methods.
>
> HTH,
> Alistair
>
>
>
>> On 21/03/18 17:55, Alistair Grant wrote:
>>> On 21 March 2018 at 03:12, dragoncity <[hidden email]> 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
>>>
>>>
>> --
>> Cheers,
>> Brett
>>
>

> When I run the
>
> |ui | ... etc.... from a Playground, I don't get a working UI Form, but
> I get a correctly defined static image layout of the form under 'Morph' IN
> the Playground.
>
> I expected the CustomerSatisfaction UI form to appear as a independent
> item on the Pharo 'world'.
>
> Now what am I doing wrong ? :-)

> Thank you -- of course ! I had that  "ui close" in my code !!! , I'd expected
> the
> form to take control until I exited the form itself and had not considered
> the code would 'fall straight through' to the 'ui close'
>
>
> The example form now displays on Pharo's World and is active as expected.
>
> From my experience with trying to get this example working, I think the
> chapter needs a bit of expansion & more explanation
> about some features used. The Class method creation verse the instance
> methods being an example. I guess the authors assume most people will have
> worked with Pharo  without jumping straight to the GUI interfacing !!

>
> Thank you all for your help, getting this example running is a very
> important step to understanding Pharo's UI.
>
>
>
>
>
> --
> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
>