October 2019 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Running a teapot instance remotely

by Vince Refiti

Hi Joachim I see. I have submitted a pull request to change the wording to reflect the real situation. By the way I work professionally on a 20 year old VA Smalltalk app that we just upgraded from 6 to 9. That thing is solid as a rock and only walksback with bad code. Nothing ever else goes wrong. Vince -----Original Message----- From: Pharo-users [mailto:pharo-users-bounces@lists.pharo.org] On Behalf Of jtuchel(a)objektfabrik.de Sent: Friday, 11 October 2019 4:09 PM To: pharo-users(a)lists.pharo.org Subject: Re: [Pharo-users] Running a teapot instance remotely EXTERNAL: Do not click links or open attachments if you do not recognize the sender. Vince, I guess this has its roots in long-ongoing discussions about the anticipated disadvantages of image-based development in general. It tries to explain that Smalltalk has mechanisms for recovering code after an image crashes. It is not indicating that images do actually crash more often than other development environments. It is more a remark about the fact that of course even Smalltalk can crash and that there is a mechanism (namely the changes file and changes browsers) for restoring your code after a crash, even if you didn't file-out your code or didn't push it to an external repository. Nothing more, nothing less. So please don't read this as: "Since Pharo/Smalltalk isn't stable, we had to xyz" - this is not the case. I've been using Smalltalk (mostly not Pharo) for more than 25 years and I can only remember having a need to recover source code maybe a hand full of times. In my favorite Smalltalk (VA Smalltalk), I am almost 100% sure I never had this issue because Envy is exactly the measure that is mentioned in the sentence you cited. Joachim Am 11.10.19 um 07:39 schrieb Vince Refiti: > Hi > > This brings up some questions I have been meaning to ask for some time. The sentence "When the Pharo image crashes (which will happen), there must be a way to automatically recover from this crash." appears in the Enterprise Pharo Book. > > Does this claim still apply? Is Pharo that unstable still? > > If it is, what are the major causes in your own applications that crash it? I have run a few small, local, experimental Teapot, Seaside and other Pharo server apps and nothing crashed, but reading something like that makes me nervous about public-facing server apps in Pharo. > > Vince > > -----Original Message----- > From: Pharo-users [mailto:pharo-users-bounces@lists.pharo.org] On > Behalf Of Pierce Ng > Sent: Friday, 11 October 2019 12:39 PM > To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> > Subject: Re: [Pharo-users] Running a teapot instance remotely > > EXTERNAL: Do not click links or open attachments if you do not recognize the sender. > > On Thu, Oct 10, 2019 at 04:18:14PM -0400, sergio ruiz wrote: >> How are people keeping it running these days? > I used to use daemontools. These days I use Docker. > > Pierce > -- ----------------------------------------------------------------------- Objektfabrik Joachim Tuchel mailto:jtuchel@objektfabrik.de Fliederweg 1 https://urldefense.com/v3/__http://www.objektfabrik.de__;!09EJrJkydGw!T9iwy… D-71640 Ludwigsburg https://urldefense.com/v3/__http://joachimtuchel.wordpress.com__;!09EJrJkyd… Telefon: +49 7141 56 10 86 0 Fax: +49 7141 56 10 86 1

Oct. 13, 2019

Re: [Pharo-users] Pharo launcher

by ilker Ã¶zcan

I format my pc and reinstall windows..now it works..thank you. On Tue, Oct 8, 2019, 18:10 Christophe Demarey <christophe.demarey(a)inria.fr> wrote: > Hi Ilker, > > It looks like you got the same issue as > https://github.com/pharo-project/pharo-launcher/issues/349 > If you do not run Pharo Launcher from cmd line or unzip is not in the > path, it should works fine (waiting for a proper fix). > Please try to delete corrupted VMs (you can use Pharo Launcher VM Manager) > and try again. > > Thanks for the report, > Christophe > > > Le 8 oct. 2019 Ã 15:35, ilker Ã¶zcan <ilkozcan(a)gmail.com> a Ã©crit : > > > > When i tried to install pharo 7 and 8 with the launcher on windows 10 > there happened a message which says windows can not run 16 bit program.. > > > > It seems pharo.exe seems to be 16 bit ( i installed 64bit)..anyone with > such a problem and any idea how i can solve this? Thanks all.. > > >

Oct. 13, 2019

Re: [Pharo-users] Transcript: printString or asString

by Samuel Teixeira Santos

Hi Tim. I just learned in previous videos of the mooc about using nautilus to explore using "Implementers of..." or "Senders of..." I will do that for sure now. Thanks for your tip. Regards >

Oct. 13, 2019

Re: [Pharo-users] Transcript: printString or asString

by Tim Mackinnon

Hi - While Iâm sure everyone can give you an answer - itâs more useful to teach you how to answer these questions for your self. Try right clicking with your cursor on asString and choose âimplementors ofâ (it may have a slightly different name friending on Pharo version - or press âmetaâ-m. Do the same for printString and compare the results. Also, do the same using âsenders ofâ (meta-n). Most code in Pharo is explorable like this, and you can generally answer most questions by seeing his other code in the system interacts or uses what you are exploring. Tim Sent from my iPhone > On 13 Oct 2019, at 11:50, Samuel Teixeira Santos <arcanosam(a)gmail.com> wrote: > > Hi folks. > I'm starting in Pharo studies by FUN Mooc. > In Week 03, on An Overview of Essential Collections there is the example below: > > | days | > days := Dictionary new. > > days > at: #January put: 31; > at: #February put: 28; > at: #March put: 31. > > days keysAndValuesDo: > [ :k :v | Transcript show: k asString, ' has ', v printString, ' days' > ; cr ] > > The code in blue I change for > > days keysAndValuesDo: > [ :k :v | Transcript show: k asString, ' has ', v asString, ' days' > ; cr ] > > And works too on Playground. > > There is something different about both? There is someone better than other? > > Thanks in advance, > > > Samuel T. Santos

Oct. 13, 2019

Transcript: printString or asString

by Samuel Teixeira Santos

Hi folks. I'm starting in Pharo studies by FUN Mooc. In Week 03, on An Overview of Essential Collections there is the example below: | days | days := Dictionary new. days at: #January put: 31; at: #February put: 28; at: #March put: 31. days keysAndValuesDo: [ :k :v | Transcript show: k asString, ' has ', v printString, ' days' ; cr ] The code in blue I change for days keysAndValuesDo: [ :k :v | Transcript show: k asString, ' has ', v asString, ' days' ; cr ] And works too on Playground. There is something different about both? There is someone better than other? Thanks in advance, Samuel T. Santos

Oct. 13, 2019

Re: [Pharo-users] voyage mongo and transactionality

by jtuchel＠objektfabrik.de

Jonathan, I was a bit destracted by work this week, so I am a little late to the show... Am 10.10.19 um 12:26 schrieb Jonathan van Alteren: > Hi Joachim, > > Thank you for your feedback. > > It feels good to know we're not alone in this :-) Well, I guess there are far more people in this boat than actually know they are ;-) > Unfortunately, the things you describe are familiar to me. My business > partner Dave West has a lot of experience with applying a behavioral, > 'pure' object design approach. We're looking hard into simplifying > these matters through the application of inversion of control and by > making objects as autonomous as they can possible be. sigh, This is really, really hard. You'd need a guard in the background that autonomously register all objects that get visited/accessed/modified during an operation and create a memento just before this actually happens. Ideally, this would only happen if the upcoming operation on that objects modifies its state once the operation happens. Or ot would have to clean up non-modified ones after the operation finished. I guess this second alternative is even feasible using slots and such, but there remain a few questions about synchronizing all this and the underlying database transactions... > At the same time, we haven't found the pot of gold at the end of the > rainbow yet ;-) > You know, sometimes I fear it is better not to have anybody come back from that end of the rainbow. They might have found out there is no pot or anything similar to one ;-) > Nowadays, a fair amount of applications have a very direct way of > handling user interactions and resulting state changes. For example, > the settings of my Firefox browser doesn't have a save button anymore. > Anything I change looks to be automatically persisted. Perhaps there > is some value in that approach for 'enterprise' applications as well, > although I think there will remain a lot of use cases where an > explicit save will be needed for whatever reason. Hmm. I am afraid there is a certain distance between changes that only affect a single setting value and more complex values that imply a lot of recomputation of values in a more complex model. Sometimes you also need to modify or at least check consequences of changes that don't fit onto a single screen, and there you need to find ways to allow a user to step back from what they just started to do... > > Let's keep talking about this. I need to do some research on the > memento pattern first :-) If you have any information sources you can > point me to, I would greatly appreciate that. I don't follow any interesting research on mementos. Too much work to do for that. The memento pattern itself is just "make a copy that the user can play with without any consequences to the original object". Works perfect for a single object or a well-defined object graph. But I am not aware of any working solutions that would solve our problems for more complex graphs, or even a general one... If you find something, let us know! Joachim > > Kind regards, > > Jonathan van Alteren > > Founding Member | Object Guild > jvalteren(a)objectguild.com > On 9 Oct 2019, 16:49 +0200, jtuchel(a)objektfabrik.de > <jtuchel(a)objektfabrik.de>, wrote: >> >> This is a tricky mine field. Sometimes you need a lot of business >> functionality in objects referenced in your objects that are >> currently in the editor. So I'm still to see a project in which the >> memento pattern really worked for more complex scenarios. How deep do >> you dive to have enough memento objects to provide the functionality >> needed. I guess you can do that with some sort of object-level >> transaction framework that automatically creates mementos of whatever >> object is being navigated to during some kind of processing-context. >> I guess slots could be of use here. But this is not trivial for >> general cases. >> >> In my experience, this problem area makes for the other 70% of the >> time spent on developing GUI or Web applications, besides the 60% for >> GUI design and implementation and 25% business logic... >> >> I'd be interested to learn about patterns to handle such more complex >> things. We constantly travel back and forth between implementing >> stuff in the GUI handlers (copying values to the GUI classes that >> access themselves during GUI operations and push values to the >> business objects when the users clicks on OK), using mementos (which >> most of the times are nets of mementos that are created manually - >> "we know what we'll touch in this Editor") and operating on business >> objects directly and relying on the persistence mechanism (Glorp in >> our case) and its rollback behaviour. All three have lots of >> weaknesses and seem to have their place nevertheless. >> >> So this is a very interesting discussion and I think this is an area >> that has not been solved yet. >> >> >> Joachim >> >> >> >> >> >> >> >> Am 09.10.19 um 16:25 schrieb James Foster: >>> Thanks for the explanation. And, yes, this is an artifact of your >>> design; if you put intermediate values into domain objects then they >>> will remain in your domain objects to be seen later. From what >>> youâve described, I donât see how it would be any different in a >>> non-image environment (Java, C#, etc.), unless you re-read the >>> entire object graph from the database. As someone else mentioned, >>> this would be a good place for the Memento Pattern. >>> >>> James >>> >>>> On Oct 9, 2019, at 1:59 AM, Jonathan van Alteren >>>> <jvalteren(a)objectguild.com <mailto:jvalteren@objectguild.com>> wrote: >>>> >>>> Hi James, >>>> >>>> I see how my explanation might be unclear. >>>> >>>> We have a main form for the agenda and a subform for an item, which >>>> is shown using Seaside call/answer. The save button of the subform >>>> is clicked, which adds the item to the underlying agenda model >>>> object, but the save button of the main form _is not_Â clicked by >>>> the user. The callback for the main save button sends the save >>>> message to the agenda object, causing the database to be updated. >>>> >>>> So yes, the browser does submit the data on the subform, it's the >>>> main form component that doesn't receive the save button callback. >>>> I realize that this is in large part an issue with our design. >>>> However, the way object persistence seems to work in the image >>>> environment plays a large role. >>>> >>>> >>>> Kind regards, >>>> >>>> Jonathan van Alteren >>>> >>>> Founding Member | Object Guild >>>> jvalteren(a)objectguild.com <mailto:jvalteren@objectguild.com> >>>> On 8 Oct 2019, 15:41 +0200, James Foster <Smalltalk(a)jgfoster.net >>>> <mailto:Smalltalk@jgfoster.net>>, wrote: >>>>> >>>>>> On Oct 8, 2019, at 3:05 AM, Jonathan van Alteren >>>>>> <jvalteren(a)objectguild.com <mailto:jvalteren@objectguild.com>> wrote: >>>>>> >>>>>> We've encountered an issue where a user makes changes to an >>>>>> agenda, but does not click the Save button. Instead, the user >>>>>> closes the browser or uses the navigation to go to a different >>>>>> part of the application. When navigating back to the original >>>>>> agenda, the changes made previously (e.g. items added) are still >>>>>> being displayed, even though they were never explicitly saved. >>>>> >>>>> Here is what I donât understand: how did the change get from the >>>>> userâs client agent (browser) to the server? If you make a change >>>>> to a field in a form and then close the browser, who sent the >>>>> change to the server? If you show the save domain value in a >>>>> different location, with a dynamically-generated id and name (so >>>>> it isnât cached in the browser), or written to the Pharo >>>>> Transcript, does the value still change? That is, are you sure >>>>> that the change is in the reflected in the Smalltalk image and not >>>>> just somehow cached in the browser? >>>>> >>>>> James >>>>> >>>>> >>> >> >> -- >> ----------------------------------------------------------------------- >> Objektfabrik Joachim Tuchelmailto:jtuchel@objektfabrik.de >> Fliederweg 1http://www.objektfabrik.de >> D-71640 Ludwigsburghttp://joachimtuchel.wordpress.com >> Telefon: +49 7141 56 10 86 0 Fax: +49 7141 56 10 86 1 >> >> -- ----------------------------------------------------------------------- Objektfabrik Joachim Tuchel mailto:jtuchel@objektfabrik.de Fliederweg 1 http://www.objektfabrik.de D-71640 Ludwigsburg http://joachimtuchel.wordpress.com Telefon: +49 7141 56 10 86 0 Fax: +49 7141 56 10 86 1

Oct. 13, 2019

Re: [Pharo-users] Running a teapot instance remotely

by Joachim Tuchel

Sean, good point about dev vs. prod. Thanks for adding. I was indeed talking about development images. There is no loss of code in a runtime image, because you usually don't ship the "original" devleopment image... Of course, chances are a production image crashes when you ship bugs, but it' won't loose code. Joacim > "Sean P. DeNigris" <sean(a)clipperadams.com mailto:sean@clipperadams.com > hat am 11. Oktober 2019 um 20:07 geschrieben: > > > jtuchel wrote > > > > I guess this has its roots in long-ongoing discussions about the > > anticipated disadvantages of image-based development in general. > > > > > I would also add that IMHO a lot of (or maybe almost all) the angst of > possible image crashes comes during development (with increasing risks as > experiments get more exotic or delve deeper into the kernel), not > deployment. Crashing may be less of an issue now for professional use since > there is a development/deployment distinction, unlike historically and in a > pure Dynabook vision where all users are developers. > > > > ----- > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >

Oct. 12, 2019

Re: [Pharo-users] Running a teapot instance remotely

by Sean P. DeNigris

jtuchel wrote > I guess this has its roots in long-ongoing discussions about the > anticipated disadvantages of image-based development in general. I would also add that IMHO a lot of (or maybe almost all) the angst of possible image crashes comes during development (with increasing risks as experiments get more exotic or delve deeper into the kernel), not deployment. Crashing may be less of an issue now for professional use since there is a development/deployment distinction, unlike historically and in a pure Dynabook vision where all users are developers. ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Oct. 11, 2019

NVARCHAR and Glorp

by eftomi

Dear all, I'm working on ADO database driver for Glorp by using Pablo's PharoCOM. The structure of the driver is similar to Sven's P3DatabaseDriver and P3Client (thanks, Sven for very clear architecture :-) ) and the work is progressing quite nicely. I can connect to SQL Server, PostgreSQL and create tables, insert and read data directly with ADO Connection and Recordset objects, and with Glorp, too. In next days I'll do some more testing, including Oracle, and publish the prototype on GitHub. The goal is not PostgreSQL, of course, but to finally reach SQL Server, Oracle and possibly MS Access, at least from Windows systems. One thing is bothering me though - SQL Server supports Unicode with NCHAR and NVARCHAR types, and when using INSERT INTO with literal strings these should be prefixed with N, like in N'This is a Unicode string' Does somebody remember whether Glorp can prefix the strings in that way when constructing SQL statements? I checked all the constants and string conversions under DatabasePlatform but haven't found anything related to this kind of prefixing. Thanks and best wishes, Tomaz -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Oct. 11, 2019

Re: [Pharo-users] How to install stripe library on Pharo 7 64bit ?

by Sven Van Caekenberghe

> On 11 Oct 2019, at 13:45, jmathews via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > Pharo 7 > - Image hangs when loading Zinc HTTP Components. I tried loading Zinc HTTP > Components separately through Metacello with the same results so I don't > think the problem is with your code. Yes, that is true and very problematic. A new implementation of ZnBufferedReadWriteStream was added to Pharo 7, which gets again (partially) overwritten by Zinc HTTP Components, breaking code loading. In Pharo 8 this was fixed by renaming these special (and now changed) class(es) to SourceFileBufferedReadWriteStream/SourceFileCharacterReadWriteStream so that they are moved out of Zinc HTTP Components and cannot be overwritten/broken. Either the last 3 commits on the Pharo 7 branch must be reversed, or the fixes/renaming/usage of Pharo 8 must be back ported as well. This is urgent. Sven

Oct. 11, 2019