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why are Help topics in the meta-side

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Peter Uhnak

why are Help topics in the meta-side

All help topics (subclasses of CustomHelp) have all the content on the class-side.

This seems very weird to me, because the class-side should about managing the meta, not containing the content itself.

It feels weird.

Peter

Hannes Hirzel

Re: why are Help topics in the meta-side

This is as if you would ask

why are specs on the class side?

You may actually see Help information as 'meta information'. It is
information about ....

The content is only needed once per topic. No different instances of
the same topic.

--Hannes

On 10/3/17, Peter Uhnák <[hidden email]> wrote:

> All help topics (subclasses of CustomHelp) have all the content on the
> class-side.
>
> This seems very weird to me, because the class-side should about managing
> the meta, not containing the content itself.
>
> It feels weird.
>
> Peter
>

Specs_on_class_side_2017-10-03.png (166K) Download Attachment

Peter Uhnak

Re: why are Help topics in the meta-side

On Tue, Oct 3, 2017 at 2:17 PM, H. Hirzel <[hidden email]> wrote:

This is as if you would ask

why are specs on the class side?

I can certainly ask that, and there's in fact no reason why it would have to be there (because when the layout is being retrieved, the instance is already available).

You may actually see Help information as 'meta information'. It is
information about ....

If you put it on the class-side of the class that it is about then I would agree. But that is not the case here. The object is the content, not about the content.

The content is only needed once per topic. No different instances of the same topic.

This is not actually true; the topic is instantiated anew for every help browser opened (and every time browser is opened).

And in fact the CustomHelp subclass is recasted to HelpTopic at runtime, which makes the entire class quite pointless; which is what I don't understand.

Peter

Hannes Hirzel

Re: why are Help topics in the meta-side

The information for a help topic on the class side is used to create a
help instance.

Even if I technically create several instances of a particular help
topic with information taken from the class side conceptually I have
only _one_ help topic. The instances all share exactly the same
content.

Maybe the idea of 'Uniclass' (Etoys / Squeak') though not exactly the
same may help.
"UniClasses are classes for the instance specific behavior of just one
instance."
http://wiki.squeak.org/squeak/2402

In Smalltalk I always have to deal with classes. A class is an object
as well. Good to keep information for cases where I do not care to
have different instances with different state.

HTH

Hannes

On 10/3/17, Peter Uhnák <[hidden email]> wrote:

> On Tue, Oct 3, 2017 at 2:17 PM, H. Hirzel <[hidden email]> wrote:
>
>> This is as if you would ask
>>
>> why are specs on the class side?
>>
>
> I can certainly ask that, and there's in fact no reason why it would have
> to be there (because when the layout is being retrieved, the instance is
> already available).
>
>
>> You may actually see Help information as 'meta information'. It is
>> information about ....
>>
>
> If you put it on the class-side of the class that it is about then I would
> agree. But that is not the case here. The object is the content, not about
> the content.
>
>
>>
>> The content is only needed once per topic. No different instances of the
>> same topic.
>>
>
> This is not actually true; the topic is instantiated anew for every help
> browser opened (and every time browser is opened).
>
> And in fact the CustomHelp subclass is recasted to HelpTopic at runtime,
> which makes the entire class quite pointless; which is what I don't
> understand.
>
> Peter
>

Hannes Hirzel

Re: why are Help topics in the meta-side

In the end it is probably a matter of conventions.

Instruction how to construct something (e.g. Spec) / configuration
information / descriptions / help information / examples are kept on
the class side.

HH

On 10/3/17, H. Hirzel <[hidden email]> wrote:

> The information for a help topic on the class side is used to create a
> help instance.
>
> Even if I technically create several instances of a particular help
> topic with information taken from the class side conceptually I have
> only _one_ help topic. The instances all share exactly the same
> content.
>
> Maybe the idea of 'Uniclass' (Etoys / Squeak') though not exactly the
> same may help.
> "UniClasses are classes for the instance specific behavior of just one
> instance."
> http://wiki.squeak.org/squeak/2402
>
> In Smalltalk I always have to deal with classes. A class is an object
> as well. Good to keep information for cases where I do not care to
> have different instances with different state.
>
> HTH
>
> Hannes
>
> On 10/3/17, Peter Uhnák <[hidden email]> wrote:
>> On Tue, Oct 3, 2017 at 2:17 PM, H. Hirzel <[hidden email]>
>> wrote:
>>
>>> This is as if you would ask
>>>
>>> why are specs on the class side?
>>>
>>
>> I can certainly ask that, and there's in fact no reason why it would have
>> to be there (because when the layout is being retrieved, the instance is
>> already available).
>>
>>
>>> You may actually see Help information as 'meta information'. It is
>>> information about ....
>>>
>>
>> If you put it on the class-side of the class that it is about then I
>> would
>> agree. But that is not the case here. The object is the content, not
>> about
>> the content.
>>
>>
>>>
>>> The content is only needed once per topic. No different instances of the
>>> same topic.
>>>
>>
>> This is not actually true; the topic is instantiated anew for every help
>> browser opened (and every time browser is opened).
>>
>> And in fact the CustomHelp subclass is recasted to HelpTopic at runtime,
>> which makes the entire class quite pointless; which is what I don't
>> understand.
>>
>> Peter
>>
>

Esteban A. Maringolo

Re: why are Help topics in the meta-side

2017-10-03 10:14 GMT-03:00 H. Hirzel <[hidden email]>:
> In the end it is probably a matter of conventions.
>
> Instruction how to construct something (e.g. Spec)

Conventions and history, which maybe are the same thing :)

VisualSmalltalk/VisualWorks, Dolphin, VAST keep the definition of the
windows/panes in the class side, whether they're Smalltalk expressions
or binary/literal arrays (Dolphin).

In the case of Dolphin each "class method" defines a "resource" you
can have more than one layout for the same class, so you can have a
"read only" view (resource) and an "editable" view sharing the same
instance behavior.

Also, having it class side you can reference it/preview (rendered)
from other views without having to instantiate them, which might
require having a valid model, etc.

> / configuration information / descriptions
> / help information / examples are kept on the class side.

In fact I don't like that Magritte moved the descriptions from class
to instance side.

My two cents on this.

Regards!

Esteban A. Maringolo