Re: [squeak-dev] Separation of domain from UI in Squeak (was: 5.3 cannot rename subclasses of Error)

29 Feb 2020

      Hi Jakob,
really great to read your thoughts about this topic! :D
...
UserRequest (base class)
...
"Christoph proposed UserNotification, but notifications can be
dismissed easily, confirmations or choices should not be"
"Also Monticello and other packages already use *Request for the purpose"
InputRequest "accurate, but too general?"
Request "probably too general"
Hm, is an #inform: really a request? (One could say: yes, a request for "okay", but that's a bit philosophical ^^)
However, +1 for not naming it *Notification. In most cases, it would not be even useful to provide a non-parametrized version of #resume.
...
"asynchronous/continuation style:"
(InputRequestSubclass signal)
    eventually: [:response | ... ];
    then: [:response | ...];
    ifRejected:/ifCancelled: [...].
I never used this in practice, but it sounds useful in certain situations. But how would you implement this? Exception does not inherit from Promise.
...
"remains open whether this will be a modal popup or a message in some kind of notification area"

Notification area? Interesting concept, you're ahead of our time in Squeak ;-)
OT: Actually, I would find it more interesting/urgent to support true multiprocessing than any kind of notification area which is mainly useful if it is filled asynchronously.
Another approach might be PHNotificationhttps://github.com/tom95/Pheno/tree/master/src/Pheno-Examples.package/PHNotificationExample.class, but in general, I wonder how often developers need any secondary notification? They are mostly not so relevant and cleaning up any additional notification area can cost time and nerves ...
...
ConfirmationRequest signal: 'More letters, but looks nicer to me' trueChoice: #Agreed falseChoice: #Disagreed.
on: ConfirmationRequest do: [:request | request resume:/respond:/reply:/answer:/choose: #Agreeable].

What for do you need the symbols?
(ConfirmationRequest signal: 'Do you love Squeak?')
    ifTrue: [UserInformation signal: 'I love you too!']
    ifFalse: [ActiveHand openInHand "revenge"].
...
MultipleChoiceRequest signal: 'I think it is...' choices: #(Good Bad Done) labels: #(Yay Nay What)

Do we actually need two arrays that are connected implicitly via index? This feels kind of out-dated for me. We could use
MultipleChoiceRequest signal: 'What would you like to do?' choices: {
    'Open a Browser' -> [Browser open].
    'Open a TestRunner' -> [TestRunner open].
    'Open the help' -> [HelpBrowser open] }
... or something similar. See also #chooseFromLabeledValues:.
...
XyzRequestedFromUser signal: 'More explicit purpose, but yet another naming style'

Past participle indicates past, I'd prefer ResourceRequest or so.
...
File/Font/String/Text/Password/Credentials/ObjectRequest/ed signal: 'Likewise' initialAnswer: whatever.
"Makes me wonder whether UserRequest might imply that a user must be chosen
instead of requesting something from users"
[...]
"Can there be a protocol to request a certain kind of object from the user
or would we really need one subclass for each kind?"
Xyz requestFromUser: 'Choose your Xyz...'.
on: Xyz input/userRequest do: [:request | ...].
InputRequest signal: 'Choose your object' ofKind: Xyz.
on: InputRequest do: [:request | (request acceptsA/n: Xyz) ifTrue: [...] ifFalse: [request pass]].
...

How about:
FileDirectory class >> #resourceRequest
    ^ CustomResourceRequest new
        defaultBlock: [self default];
        uiBlock: [:request | DirectoryChooserDialog openOn: self default label: request messageText];
        yourself
"Usage:"
FileDirectory resourceRequest signal: 'Please enter a directory for purpose foo!'.
"Maybe with property dictionary:"
FileDirectory resourceRequest
    setProperty: #rootDirectory toValue: (FileDirectory on: 'c:');
    signal: 'Please enter a directory for purpose foo!'.
"Second example:"
SystemWindow class >> #resourceRequest
    ^ CustomResourceRequest new
        resourceString: 'window'; "for generating default messageText"
        uiBlock: [:request | UserChoiceRequest signal: request messageText choices: (SystemWindow windowsIn: self currentWorld)]];
        yourself
"Usage:"
SystemWindow resourceRequest signal
    ifNotNil: [:window | window comeToFront].
Or would this be too generic? Oh, what a fun to brainstorm a new object design :-)
Best,
Christoph
________________________________
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Jakob Reschke forums.jakob@resfarm.de
Gesendet: Freitag, 28. Februar 2020 23:55:12
An: The general-purpose Squeak developers list
Betreff: Re: [squeak-dev] Separation of domain from UI in Squeak (was: 5.3 cannot rename subclasses of Error)
Thinking about names and usage...
UserRequest (base class)
"Christoph proposed UserNotification, but notifications can be
dismissed easily, confirmations or choices should not be"
"Also Monticello and other packages already use *Request for the purpose"
InputRequest "accurate, but too general?"
Request "probably too general"
"contrast with WebRequest, for example"
"asynchronous/continuation style:"
(InputRequestSubclass signal)
    eventually: [:response | ... ];
    then: [:response | ...];
    ifRejected:/ifCancelled: [...].
"handling:"
on: InputRequest do: [:request | request resume:/provide:/answer:/reply:/respond: whatever].
UserInformation signalWith: 'Looks ok'
    "remains open whether this will be a modal popup or a message in some kind of notification area"
    on: UserInformation do: [:info | info resume/dismiss/accept/continue "ok"]
    "but it might also be information about (not for) a user"
    UserNotification signalWith: 'This makes more sense to me here for inform:'.
    "This is not really a request for information, only for acknowledgement"
UserConfirmation signal .... "strange because here we want to request confirmation, not give one"
    UserConfirmation request: 'Does this look better?' "but signal is still inherited"
    on: UserConfirmation do: [:confirm | "strange again because the confirmation is yet to be given or denied"]
    UserConfirmRequest signal: 'This looks wordy even though it is already abbreviated'
    UserConfirmRequest request: 'Double double words'.
    UserConfirmRequest confirm: 'Double double, and the request shall confirm something??'
    "can be circumvented with a UserConfirmation factory but then signalling and handling use different class names"
    ConfirmationRequest signal: 'More letters, but looks nicer to me' trueChoice: #Agreed falseChoice: #Disagreed.
    on: ConfirmationRequest do: [:request | request resume:/respond:/reply:/answer:/choose: #Agreeable].
    on: ConfirmationRequest do: [:request | request confirm/deny].
    "ConfirmationRequested also possible, but not a noun -- different style"
MultipleChoiceRequest signal: 'I think it is...' choices: #(Good Bad Done) labels: #(Yay Nay What)
    "unfortunately the class name is already taken in RefactoringTools"
    ChoiceRequest signal: 'shorter but maybe stranger?' choices: #(Yep Nope)
        MultiResponseRequest signal: 'I like...' responses: #(Cats Dogs Squeak You)
        "funnily the term 'multiple choice' implies a single answer from a set of many"
        ConfirmationRequest "or others (see above) could also be a subclass of multiple choice"
        ClassOrTraitRequest signal: 'Choose your request'.
        (ClassOrTraitRequest fromPattern: '*Class*Request') signal: 'Other ideas?'
        ClassifierRequest signal: 'Do you prefer UML-speak?'
    DirectoryRequest signal: 'What kinds of other requests to/from/by/with/... a directory are there?'
    DirectoryRequested signal: 'This might be less ambiguous'
    File/Font/String/Text/Password/Credentials/ObjectRequest/ed signal: 'Likewise' initialAnswer: whatever.
    "Makes me wonder whether UserRequest might imply that a user must be chosen
    instead of requesting something from users"
    XyzRequestedFromUser signal: 'More explicit purpose, but yet another naming style'
    "Can there be a protocol to request a certain kind of object from the user
    or would we really need one subclass for each kind?"
    Xyz requestFromUser: 'Choose your Xyz...'.
    on: Xyz input/userRequest do: [:request | ...].
    InputRequest signal: 'Choose your object' ofKind: Xyz.
    on: InputRequest do: [:request | (request acceptsA/n: Xyz) ifTrue: [...] ifFalse: [request pass]].
    ...
There is also ProgressInitiationException which does not have a nice name.
It is not a request, but it already has displayProgress:* in UIManager
as defaultAction.
Alternative names:
ProgressInitiation/ed
ProgressStart/ed
Am Fr., 28. Feb. 2020 um 22:11 Uhr schrieb Jakob Reschke <forums.jakob@resfarm.demailto:forums.jakob@resfarm.de>:
HI,
Unless there is a good reason why handling ProvideAnswerNotification
is not a good idea in scripted environments, I agree with Chris. I
would prefer using the existing mechanism to introducing a strange
synonym for Notification.
Swapping the control flow, like Christoph proposed (user code signals
the notification and defaultAction is the modal dialog), sounds ok to
me too. It would also mean that user code does not have to access the
UIManager singleton. On the other hand, it is less obvious whether
something is meant to be a UI interaction if the names of the
Notifications make the code strange to read. For the most basic cases,
at least there still is Object>>inform:/confirm:/confirm:orCancel:.
Kind regards,
Jakob
Am Mi., 26. Feb. 2020 um 22:41 Uhr schrieb Chris Muller <asqueaker@gmail.commailto:asqueaker@gmail.com>:
...
Hi Marcel,
...
...
especially for this one tiny little thing of a modal alert when renaming classes?
It is a more general issue. There should be no UI invocation code in a non-UI part of the system. So, "Transcript showln:." is fine but "self inform:" is not. Why? Because those cannot be trapped in scripts, which is - for example - unfortunate in automated pipelines such as our CI.
Actually, they can.
"example 1"
[ self inform: 'stop everything and pay attention to me!' ] on: ProvideAnswerNotification do: [ : noti | noti resume ]     "nil"

"example 2"
[UIManager default request: 'what is the answer?' initialAnswer: 'tell me now!' ] on: ProvideAnswerNotification do: [ : noti | noti resume: 42 ]      "42 "

I assumed this is what the CI jobs were doing.. they're not?
I totally share your sentiments about no UI invocation code in the domain, and is how I do my own designs, of course, but Squeak chose default to being an <<interactive system>>, and requires handlers of ProvideAnswerNotification to make it non-interactive, rather than the other way around.
If you want to flip the above in 5.4 to the normal way -- signaling a kind of ProvideAnswerNotification whose defaultAction issues the modal popup -- then let's flip them, but it doesn't seem like we need a new layer of notification classes just yet.  ProvideAnswerNotification may be sufficient.
Best,
  Chris
...
...
What happened to simply opening up a MessageSet on the references afterward?
Still there. Unrelated to this issue. See the end of Browser >> #renameClass.
...
Say, why do we need a modal alert at all?
I agree, that extra check in Class >> #rename: might not be necessary and maybe moved to our refactoring tools.
Best,
Marcel
Am 26.02.2020 00:21:48 schrieb Chris Muller <asqueaker@gmail.commailto:asqueaker@gmail.com>:
-1.  "Notice" is such a generic, common word to steal from all applications that might want to create their own, especially for this one tiny little thing of a modal alert when renaming classes?  Say, why do we need a modal alert at all?  What happened to simply opening up a MessageSet on the references afterward?

Chris

On Tue, Feb 25, 2020 at 8:17 AM Marcel Taeumel <marcel.taeumel@hpi.demailto:marcel.taeumel@hpi.de> wrote:
...
Just "Notice"?
Am 25.02.2020 12:11:33 schrieb Eliot Miranda <eliot.miranda@gmail.commailto:eliot.miranda@gmail.com>:
On Feb 25, 2020, at 1:40 AM, Marcel Taeumel <marcel.taeumel@hpi.demailto:marcel.taeumel@hpi.de> wrote:

Fixed. BUT: Please take a look at
Kernel-mt.1305
Tools-mt.941
We need a name! :-)
On second thoughts Notice might be a better name.
Best,
Marcel
Am 25.02.2020 10:11:22 schrieb Marcel Taeumel <marcel.taeumel@hpi.demailto:marcel.taeumel@hpi.de>:
...
Maybe it is a sporadic issue?
It is! Related to the ProgressNotification which I accidentially catch in Browser >> #renameClass. I wanted to get the UI call out of Class >> #rename:.
That progress notification does not appear every time. Only above a certain threshold. That's why it appears to be sporadic.
Best,
Marcel
Am 25.02.2020 09:37:13 schrieb Thiede, Christoph <christoph.thiede@student.hpi.uni-potsdam.demailto:christoph.thiede@student.hpi.uni-potsdam.de>:
I could reproduce it one single time ... Maybe it is a sporadic issue?
Best,
Christoph

Von: Squeak-dev <squeak-dev-bounces@lists.squeakfoundation.orgmailto:squeak-dev-bounces@lists.squeakfoundation.org> im Auftrag von Taeumel, Marcel
Gesendet: Dienstag, 25. Februar 2020 09:34:03
An: John Pfersich via Squeak-dev; Chris Muller
Betreff: Re: [squeak-dev] 5.3 cannot rename subclasses of Error
Hmm... I can reproduce the bug. Yet, calling "Error2 rename: #Error1" from a workspace works fine. Strange.
Best,
Marcel
Am 25.02.2020 09:16:13 schrieb Thiede, Christoph <christoph.thiede@student.hpi.uni-potsdam.demailto:christoph.thiede@student.hpi.uni-potsdam.de>:
Hi Chris,
in a fresh image, I cannot reproduce this. Are you sure the class has not been renamed or is it possible that the class list was not updated properly?
Best,
Christoph

Von: Squeak-dev <squeak-dev-bounces@lists.squeakfoundation.orgmailto:squeak-dev-bounces@lists.squeakfoundation.org> im Auftrag von Chris Muller <asqueaker@gmail.commailto:asqueaker@gmail.com>
Gesendet: Dienstag, 25. Februar 2020 06:29:00
An: squeak dev
Betreff: [squeak-dev] 5.3 cannot rename subclasses of Error
In trunk / 5.3 RC.

Make a subclass of Error called MyError1
Make a subclass of Error called MyError2
Delete MyError1
Try to rename MyError2 to MyError1

The last step fails.  No errors or debuggers, but the class is not renamed.
Works in 5.2.