April 2021 - Pharo-users - lists.pharo.org

[ANN] Next Pharo Sprint: April 30

by Marcus Denker

Next Pharo Sprint: April 30 We will organize a Pharo sprint / Moose dojo April 30 Goals of this sprint: - Fix issues from tracker https://github.com/pharo-project/pharo/issues - Especially checking older issues This is a Remote Sprint, it happens on Discord. http://pharo.org/contribute-events We have added a Board to coordinate the work: https://github.com/orgs/pharo-project/projects/9 A list of all Pharo Event of the year an be found here: https://association.pharo.org/events

April 27, 2021

Re: Announcements - and whether its bad to check if a subscription would be handled?

by Sven Van Caekenberghe

The whole idea is to decouple producers and consumers, like in messaging systems. You should not care if there are other listening, just like the listeners should not care if there is someone posting data. Asking for subscribers is introducing a coupling. The announcement mechanism will/should deal with this in an efficient way. > On 27 Apr 2021, at 16:03, Tim Mackinnon <tim(a)testit.works> wrote: > > From my rather long ramble below - I am still curious if its distasteful to have a method on Announcer > > hasSubscriptionsHandling: anAnnouncement > "Answer true if I have any subscribers to anAnnouncement" > > ^(registry subscriptionsHandling: anAnnouncement ) notEmpty > > Tim > > On Thu, 22 Apr 2021, at 11:34 PM, Tim Mackinnon wrote: >> Hi everyone - Iâve always thought the article on announcements many >> years ago was very cool - and we donât seem to use them as much as we >> could (but equally they arenât a panacea to be overused everywhere >> either - and they do get used in Pharo to some extent). >> >> Anyway, Iâve been playing around with CodeParadise (CP is a very cool >> project, and Erik is very supportive and thinking about how to write >> web apps a different wayâ¦ Iâm fascinated), >> >> And - CP uses announcements as mechanism to send events from the View >> Client (in a web browser) to a Presenter on the server (which makes >> total sense). >> >> In taking things for a spin, I hit an interesting problem on how in a >> web component world, you should display a spelling test of words - >> >> e.g. SpellingTest â has many â> SpellingWord(s). >> >> >> Initially I bunged it all in a single presenter with its associated >> view, and it was a bit messy, and Erik guided me down a route (that CP >> nicely supports) - that my SpellingTest view should have the name/date >> of the test as well as an add word input field, but the list of current >> Words (which I had bunged into a table) - were actually more elegant as >> sub-components - hence a WordView - which renders a single word in a >> DIV, and for the edit screen I was creating, a Delete button next to >> the word (so you could delete it). So a 1 to many relationship >> essentials. >> >> This is where the announcements kick in (and lead to my ultimate question). >> >> When you click the Delete button, if I use a sub component - my view >> will generate a DeleteWordAnnouncement - which gets fed to my >> SpellingWordPresenter - however words in this sense donât naturally >> know their parent (the SpellingTest) - and its the parent test that has >> a #deleteWord: method. >> >> Iâve been taking with Erik, on different ways to elegantly handle this. >> >> a) you could change the model so words know their parent (in my case, >> Iâm using a 3rd party model for Flashcards, and they just donât know >> this - and adapting them would be a nuisance >> b) my TestPresenter could listen to announcements on the WordPresenter >> - and I could get some communications between presenters (although >> normally the Presenters just get events from Views, and pure domain >> models - so it feels a bit abnormal to consider another Presenter as a >> sort of model - but I could live with this >> c) given the composable nature of views/presenters (and CP is base on a >> WebComponent model) - you could bubble up Announcements, so that if an >> event isnât handled by a viewâs immediate presenter, you could re-route >> it to the parent of the View (the component owner) and see if itâs >> presenter could do something. >> >> >> I think (c) has a certain expectation to it - in fact when I converted >> my initial one-presenter attempt into components, I still had listener >> code in my TestPresenter that was expecting to get a deleteWord >> announcement and I was initially surprised that I wasnât getting it (as >> it was now just going to the Word component I had refactored out). >> >> So I wonder if others here would expect things to work this way too >> (and are there other examples in the wild that lead you here - or scare >> you away from this?). >> >> Back to my Announcement question - if C is a good idea - why doesnât >> the Announcer class let you check if if will handle a particular >> announcement? The API has #hasSubscriber: and #hasSubscriberClass: , >> but its missing: >> >> hasSubscriptionsHandling: anAnnouncement >> "Answer true if I have any subcribers to anAnnouncement" >> >> ^(registry subscriptionsHandling: anAnnouncement ) notEmpty >> >> >> And I am wondering if this is because it's a bad thing to expect to be >> able to check? In my case above, I would want to do this to know if CP >> should instead try announcing a message to a parent presenter because >> the current presenter wonât handle it. In my example above, my >> WordComponentView will broadcast that the delete button was clicked, >> but its actually a parent view which would reasonably want to listen to >> this kind of event and process the delete. And in a many words >> scenario (the Test has many words), its unrealistic for the parent to >> register to listen to each word component individually (in fact CP sort >> of hides this from you), however if you could listen to an event in >> your TestView, it seems to come out quite nicely - and looks a bit >> like this: >> >> viewCreated >> super viewCreated. >> >> self view >> when: CpNavigationAnnouncement >> do: [ :action | self model goto: action location ]; >> >> when: CpAddWordAnnouncement do: [ :action | self addWord: action data >> ]; >> when: CpDeleteWordAnnouncement do: [ :action | self deleteWord: >> action data ]. <â this is the one Iâm talking about >> >> >> So Iâm curious on the overall thought process here, but in particular >> whether I should even submit a PR on Announcer for >> #hasSubscriptionsHandling: ? >> >> Tim >> >>

April 27, 2021

Re: Announcements - and whether its bad to check if a subscription would be handled?

by Esteban Maringolo

Exceptions are real, so your use case might justify it. In my experience I never had to test whether an announcer has some subscription, and before using announcements whether an object has some "listener" to some event. I always saw announcements as a fire and forget kind of architecture. Not sure if I'm answering your question (probably not), but let's start this conversation :-) Esteban A. Maringolo On Tue, Apr 27, 2021 at 11:04 AM Tim Mackinnon <tim(a)testit.works> wrote: > From my rather long ramble below - I am still curious if its distasteful > to have a method on Announcer > > hasSubscriptionsHandling: anAnnouncement > "Answer true if I have any subscribers to anAnnouncement" > > ^(registry subscriptionsHandling: anAnnouncement ) notEmpty > > Tim > > On Thu, 22 Apr 2021, at 11:34 PM, Tim Mackinnon wrote: > > Hi everyone - Iâve always thought the article on announcements many > > years ago was very cool - and we donât seem to use them as much as we > > could (but equally they arenât a panacea to be overused everywhere > > either - and they do get used in Pharo to some extent). > > > > Anyway, Iâve been playing around with CodeParadise (CP is a very cool > > project, and Erik is very supportive and thinking about how to write > > web apps a different wayâ¦ Iâm fascinated), > > > > And - CP uses announcements as mechanism to send events from the View > > Client (in a web browser) to a Presenter on the server (which makes > > total sense). > > > > In taking things for a spin, I hit an interesting problem on how in a > > web component world, you should display a spelling test of words - > > > > e.g. SpellingTest â has many â> SpellingWord(s). > > > > > > Initially I bunged it all in a single presenter with its associated > > view, and it was a bit messy, and Erik guided me down a route (that CP > > nicely supports) - that my SpellingTest view should have the name/date > > of the test as well as an add word input field, but the list of current > > Words (which I had bunged into a table) - were actually more elegant as > > sub-components - hence a WordView - which renders a single word in a > > DIV, and for the edit screen I was creating, a Delete button next to > > the word (so you could delete it). So a 1 to many relationship > > essentials. > > > > This is where the announcements kick in (and lead to my ultimate > question). > > > > When you click the Delete button, if I use a sub component - my view > > will generate a DeleteWordAnnouncement - which gets fed to my > > SpellingWordPresenter - however words in this sense donât naturally > > know their parent (the SpellingTest) - and its the parent test that has > > a #deleteWord: method. > > > > Iâve been taking with Erik, on different ways to elegantly handle this. > > > > a) you could change the model so words know their parent (in my case, > > Iâm using a 3rd party model for Flashcards, and they just donât know > > this - and adapting them would be a nuisance > > b) my TestPresenter could listen to announcements on the WordPresenter > > - and I could get some communications between presenters (although > > normally the Presenters just get events from Views, and pure domain > > models - so it feels a bit abnormal to consider another Presenter as a > > sort of model - but I could live with this > > c) given the composable nature of views/presenters (and CP is base on a > > WebComponent model) - you could bubble up Announcements, so that if an > > event isnât handled by a viewâs immediate presenter, you could re-route > > it to the parent of the View (the component owner) and see if itâs > > presenter could do something. > > > > > > I think (c) has a certain expectation to it - in fact when I converted > > my initial one-presenter attempt into components, I still had listener > > code in my TestPresenter that was expecting to get a deleteWord > > announcement and I was initially surprised that I wasnât getting it (as > > it was now just going to the Word component I had refactored out). > > > > So I wonder if others here would expect things to work this way too > > (and are there other examples in the wild that lead you here - or scare > > you away from this?). > > > > Back to my Announcement question - if C is a good idea - why doesnât > > the Announcer class let you check if if will handle a particular > > announcement? The API has #hasSubscriber: and #hasSubscriberClass: , > > but its missing: > > > > hasSubscriptionsHandling: anAnnouncement > > "Answer true if I have any subcribers to anAnnouncement" > > > > ^(registry subscriptionsHandling: anAnnouncement ) notEmpty > > > > > > And I am wondering if this is because it's a bad thing to expect to be > > able to check? In my case above, I would want to do this to know if CP > > should instead try announcing a message to a parent presenter because > > the current presenter wonât handle it. In my example above, my > > WordComponentView will broadcast that the delete button was clicked, > > but its actually a parent view which would reasonably want to listen to > > this kind of event and process the delete. And in a many words > > scenario (the Test has many words), its unrealistic for the parent to > > register to listen to each word component individually (in fact CP sort > > of hides this from you), however if you could listen to an event in > > your TestView, it seems to come out quite nicely - and looks a bit > > like this: > > > > viewCreated > > super viewCreated. > > > > self view > > when: CpNavigationAnnouncement > > do: [ :action | self model goto: action location ]; > > > > when: CpAddWordAnnouncement do: [ :action | self addWord: > action data > > ]; > > when: CpDeleteWordAnnouncement do: [ :action | self > deleteWord: > > action data ]. <â this is the one Iâm talking about > > > > > > So Iâm curious on the overall thought process here, but in particular > > whether I should even submit a PR on Announcer for > > #hasSubscriptionsHandling: ? > > > > Tim > > > > >

April 27, 2021

Re: creating a subclass in system browser

by Russ Whaley

Can you send a screenshot of the plus button? I'm using v9 on MacOS and I don't see a class + button... On Tue, Apr 27, 2021 at 9:47 AM kmo <voxkmp(a)gmail.com> wrote: > Doing it by hand is fiddly and error-prone. I know - because that's the > way I > used to do it before I realised that the plus button at the top of the > browser bottom panel did it for me. (I had no idea that there was also a > menu option on the refactorings menu). I think you might find the button to > be the better way - I did. > > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > -- Russ Whaley whaley.russ(a)gmail.com

April 27, 2021

Re: Announcements - and whether its bad to check if a subscription would be handled?

by Tim Mackinnon

>From my rather long ramble below - I am still curious if its distasteful to have a method on Announcer hasSubscriptionsHandling: anAnnouncement "Answer true if I have any subscribers to anAnnouncement" ^(registry subscriptionsHandling: anAnnouncement ) notEmpty Tim On Thu, 22 Apr 2021, at 11:34 PM, Tim Mackinnon wrote: > Hi everyone - Iâve always thought the article on announcements many > years ago was very cool - and we donât seem to use them as much as we > could (but equally they arenât a panacea to be overused everywhere > either - and they do get used in Pharo to some extent). > > Anyway, Iâve been playing around with CodeParadise (CP is a very cool > project, and Erik is very supportive and thinking about how to write > web apps a different wayâ¦ Iâm fascinated), > > And - CP uses announcements as mechanism to send events from the View > Client (in a web browser) to a Presenter on the server (which makes > total sense). > > In taking things for a spin, I hit an interesting problem on how in a > web component world, you should display a spelling test of words - > > e.g. SpellingTest â has many â> SpellingWord(s). > > > Initially I bunged it all in a single presenter with its associated > view, and it was a bit messy, and Erik guided me down a route (that CP > nicely supports) - that my SpellingTest view should have the name/date > of the test as well as an add word input field, but the list of current > Words (which I had bunged into a table) - were actually more elegant as > sub-components - hence a WordView - which renders a single word in a > DIV, and for the edit screen I was creating, a Delete button next to > the word (so you could delete it). So a 1 to many relationship > essentials. > > This is where the announcements kick in (and lead to my ultimate question). > > When you click the Delete button, if I use a sub component - my view > will generate a DeleteWordAnnouncement - which gets fed to my > SpellingWordPresenter - however words in this sense donât naturally > know their parent (the SpellingTest) - and its the parent test that has > a #deleteWord: method. > > Iâve been taking with Erik, on different ways to elegantly handle this. > > a) you could change the model so words know their parent (in my case, > Iâm using a 3rd party model for Flashcards, and they just donât know > this - and adapting them would be a nuisance > b) my TestPresenter could listen to announcements on the WordPresenter > - and I could get some communications between presenters (although > normally the Presenters just get events from Views, and pure domain > models - so it feels a bit abnormal to consider another Presenter as a > sort of model - but I could live with this > c) given the composable nature of views/presenters (and CP is base on a > WebComponent model) - you could bubble up Announcements, so that if an > event isnât handled by a viewâs immediate presenter, you could re-route > it to the parent of the View (the component owner) and see if itâs > presenter could do something. > > > I think (c) has a certain expectation to it - in fact when I converted > my initial one-presenter attempt into components, I still had listener > code in my TestPresenter that was expecting to get a deleteWord > announcement and I was initially surprised that I wasnât getting it (as > it was now just going to the Word component I had refactored out). > > So I wonder if others here would expect things to work this way too > (and are there other examples in the wild that lead you here - or scare > you away from this?). > > Back to my Announcement question - if C is a good idea - why doesnât > the Announcer class let you check if if will handle a particular > announcement? The API has #hasSubscriber: and #hasSubscriberClass: , > but its missing: > > hasSubscriptionsHandling: anAnnouncement > "Answer true if I have any subcribers to anAnnouncement" > > ^(registry subscriptionsHandling: anAnnouncement ) notEmpty > > > And I am wondering if this is because it's a bad thing to expect to be > able to check? In my case above, I would want to do this to know if CP > should instead try announcing a message to a parent presenter because > the current presenter wonât handle it. In my example above, my > WordComponentView will broadcast that the delete button was clicked, > but its actually a parent view which would reasonably want to listen to > this kind of event and process the delete. And in a many words > scenario (the Test has many words), its unrealistic for the parent to > register to listen to each word component individually (in fact CP sort > of hides this from you), however if you could listen to an event in > your TestView, it seems to come out quite nicely - and looks a bit > like this: > > viewCreated > super viewCreated. > > self view > when: CpNavigationAnnouncement > do: [ :action | self model goto: action location ]; > > when: CpAddWordAnnouncement do: [ :action | self addWord: action data > ]; > when: CpDeleteWordAnnouncement do: [ :action | self deleteWord: > action data ]. <â this is the one Iâm talking about > > > So Iâm curious on the overall thought process here, but in particular > whether I should even submit a PR on Announcer for > #hasSubscriptionsHandling: ? > > Tim > >

April 27, 2021

Re: creating a subclass in system browser

by kmo

Doing it by hand is fiddly and error-prone. I know - because that's the way I used to do it before I realised that the plus button at the top of the browser bottom panel did it for me. (I had no idea that there was also a menu option on the refactorings menu). I think you might find the button to be the better way - I did. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

April 27, 2021

Re: creating a subclass in system browser

by Russ Whaley

Now I'm wondering if I'm doing something wrong, or short-circuiting the correct approach... When I want to subclass - I simply select the class, and update the class definition page - moving the subclass name (which is the current class) to the class section, and replacing the subclass name with my new subclass name. I can also take care of instance and class variables I need... just save and everything seems to work just fine. Is there a reason to need to do this with a menu? Many times with menu options I'm unclear WHAT it's operating ON :) Nice to know there are multiple ways to get things done in Pharo!! On Tue, Apr 27, 2021 at 8:43 AM kmo <voxkmp(a)gmail.com> wrote: > I'm not surprised you missed it. I think it's not very intuitive having it > on > the refactoring sub-menu - especially when you already have "new class" on > the right click menu when you select a class. Why not have "create > subclass" > there as well? > > By the way, did you have trouble working out the "normal" way of creating a > subclass? You select the class definition tab in the browser bottom panel > and press the + (plus) button. It took me ages and ages to work that out. > Am > I just slow or is that also counter-intuitive? > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > -- Russ Whaley whaley.russ(a)gmail.com

April 27, 2021

Re: creating a subclass in system browser

by Sanjay Minni

No, I was not aware of the "+" in class definition tab. actually it's not there (yet) in Pharo 9 Win 64 which I am using. On Tue, 27 Apr 2021 at 18:13, kmo <voxkmp(a)gmail.com> wrote: > I'm not surprised you missed it. I think it's not very intuitive having it > on > the refactoring sub-menu - especially when you already have "new class" on > the right click menu when you select a class. Why not have "create > subclass" > there as well? > > By the way, did you have trouble working out the "normal" way of creating a > subclass? You select the class definition tab in the browser bottom panel > and press the + (plus) button. It took me ages and ages to work that out. > Am > I just slow or is that also counter-intuitive? > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >

April 27, 2021

Re: creating a subclass in system browser

by kmo

I'm not surprised you missed it. I think it's not very intuitive having it on the refactoring sub-menu - especially when you already have "new class" on the right click menu when you select a class. Why not have "create subclass" there as well? By the way, did you have trouble working out the "normal" way of creating a subclass? You select the class definition tab in the browser bottom panel and press the + (plus) button. It took me ages and ages to work that out. Am I just slow or is that also counter-intuitive? -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

April 27, 2021

Re: creating a subclass in system browser

by Sanjay Minni

Thanks Sorry I missed it. (I did not expect it in refactorings) Noury Bouraqadi-2 wrote > It's already available. > > On Apr 27 2021, at 1:03 pm, Sanjay Minni < > sm@ > > wrote: >> Hi >> >> is there a way I can create a subclass when I have selected a class in >> the >> System Browser class list (top 2nd panel). >> >> Couldnt see any option - Or is it that no such feature is needed >> >> >> ----- >> cheers, >> Sanjay >> -- >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >> > > > > Screenshot 2021-04-27 at 13.18.24.png (142K) > <http://forum.world.st/attachment/5129178/0/Screenshot%202021-04-27%20at%2013.18.24.png> ----- cheers, Sanjay -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

April 27, 2021