September 2011 - Pharo-users

Now available: a database conectivity API and its MySQL implementation

by Anindya Haldar

I am extremely pleased to offer to the community a generic Smalltalk API for database connectivity API, along with a MySQL implementation written from ground up. Think of JDBC and DBI like interfaces in other languages and environments, and this one offers abstract facilities like connection, prepared statement, resultset, row, metdata and so on for the application. The API implementation uses driver delegates, and insulates the applications from the driver specific interfaces. As of now, a MySQL implementation is available, with other databases engine supports in the future plans. The API supports server side prepared statements and cursor based fetch implemented in the MySQL driver. The implementation is currently available in 3 parts: 1) StdbCore project: This is primarily the API definitions and the delegation logic URL: http://www.squeaksource.com/StdbCore.html 2) StdbMysqlImpl project: This is the MySQL implementation of the StdbCore API URL: http://www.squeaksource.com/StdbMysqlImpl.html 3) StdbMysqlProtocol project: This is the underlying MySQL protocol driver, and used by the MySQL API implementation URL: http://www.squeaksource.com/StdbMysqlProtocol.html There is a package load ordering dependency (documented in the MySQL implementation project). Please load the core and the protocol driver packages first, before you load the implementation package. Combined, the packages has around 200 tests (most of them in the protocol driver and the API implementation) and are running green on Pharo 1.1.1 one click, Squeak 4.2 one click, Squeak 3.10 (with Seaside 2-8-573 dev image) under Mac OS X 10.5.8 with MySQL server 5.0.67. This was in the making for some time; and I feel it is time to share it with the community. I will continue to post more documentation and code snippets in the project page Wiki sections. For now, looking up the tests may be your best guide. Happy programming! Best, Anindya Haldar

Sept. 29, 2011

Re: [Pharo-users] A small problem with ScaledDecimal

by Larry White

On Tue, Sep 27, 2011 at 7:44 AM, Davorin Rusevljan < davorin.rusevljan(a)gmail.com> wrote: > On Tue, Sep 27, 2011 at 1:37 PM, Larry White <ljw1001(a)gmail.com> wrote: > > Hi, I had a need to replace the printOn: implementation in ScaledDecimal > so > > that it didn't include the scale. In other words, I don't want my users > to > > see '3.02s2'. Being lazy, my first impulse was to remove the code from > > printOn: that appends the scale, but I realized I'd have to do that every > > time I upgraded my pharo version. > > Instead I tried to implement a subclass called DisplayableScaledDecimal > and > > override printOn. That seems straightforward and smalltalky, but when I > do > > math on instances of DisplayableScaledDecimal, the results are converted > > back to ScaledDecimal. Now I'm looking at re-implementing all the math > > logic in scaledDecimal to avoid that. > > The problem seems to be in the coerce: method, which reads: > > coerce: aNumber > > "Note: this quick hack could be replaced by double dispatching" > > aNumber class = self class ifTrue: [^self class newFromNumber: aNumber > > scale: (scale max: aNumber scale)]. > > (aNumber isFraction or: [aNumber isInteger]) ifTrue: [^self class > > newFromNumber: aNumber scale: scale]. > > ^aNumber > > I guess I could override coerce:, but that seems wrong. > > So my question to the smalltalk gods on the list is: Could this be fixed > > with double dispatching as the comment sort of suggests, and would it be > a > > useful thing to do? > > hm not sure about that. > > It is usually a good idea that Smalltalk can read object from > representation that is outputed from #printOn: , and loosing a scale > in #printOn: seems to defeat that rule of the thumb. > I appreciate the heads-up, but the comment for storeOn: says that storeOn: should be used for storage because printOn: can lose precision. I guess maybe I misunderstood the intent here (time to check the blue book) but I thought storeOn: was for machines and printOn: for humans, roughly speaking. FWIW, I think the rule of thumb that says "programs should be written to be read by human's first and computers second" is violated by having the standard display for a simple decimal number include the scale. as an aside: I just watched an old video where Dan Ingalls shows how easy it is to override a numeric type in Smalltalk and just implement the methods that differ. But that was before ScaledDecimal was around. ;) But I think you're generally right about this and I was fighting against the language implementation, so I implemented a couple of String constructors that take and format scaled decimals and will scatter them throughout my ui. It's no worse than formatting dates I guess. thanks. > So maybe avoiding messing with #printOn: is better idea, and > introducing a message of your own that converts to the format you wish > is a better way. > Just my 2c > > Davorin Rusevljan > http://www.cloud208.com/ > >

Sept. 27, 2011

Re: [Pharo-users] A small problem with ScaledDecimal

by Davorin Rusevljan

On Tue, Sep 27, 2011 at 1:37 PM, Larry White <ljw1001(a)gmail.com> wrote: > Hi, I had a need to replace the printOn: implementation in ScaledDecimal so > that it didn't include the scale. Â In other words, I don't want my users to > see '3.02s2'. Â Being lazy, my first impulse was to remove the code from > printOn: that appends the scale, but I realized I'd have to do that every > time I upgraded my pharo version. > Instead I tried to implement a subclass called DisplayableScaledDecimal and > override printOn. Â That seems straightforward and smalltalky, but when I do > math on instances of DisplayableScaledDecimal, the results are converted > back to ScaledDecimal. Â Now I'm looking at re-implementing all the math > logic in scaledDecimal to avoid that. > The problem seems to be in the coerce: method, which reads: > coerce: aNumber > "Note: this quick hack could be replaced by double dispatching" > aNumber class = self class ifTrue: [^self class newFromNumber: aNumber > scale: (scale max: aNumber scale)]. > (aNumber isFraction or: [aNumber isInteger]) ifTrue: [^self class > newFromNumber: aNumber scale: scale]. > ^aNumber > I guess I could override coerce:, but that seems wrong. > So my question to the smalltalk gods on the list is: Could this be fixed > with double dispatching as the comment sort of suggests, and would it be a > useful thing to do? hm not sure about that. It is usually a good idea that Smalltalk can read object from representation that is outputed from #printOn: , and loosing a scale in #printOn: seems to defeat that rule of the thumb. So maybe avoiding messing with #printOn: is better idea, and introducing a message of your own that converts to the format you wish is a better way. Just my 2c Davorin Rusevljan http://www.cloud208.com/

Sept. 27, 2011

A small problem with ScaledDecimal

by Larry White

Hi, I had a need to replace the printOn: implementation in ScaledDecimal so that it didn't include the scale. In other words, I don't want my users to see '3.02s2'. Being lazy, my first impulse was to remove the code from printOn: that appends the scale, but I realized I'd have to do that every time I upgraded my pharo version. Instead I tried to implement a subclass called DisplayableScaledDecimal and override printOn. That seems straightforward and smalltalky, but when I do math on instances of DisplayableScaledDecimal, the results are converted back to ScaledDecimal. Now I'm looking at re-implementing all the math logic in scaledDecimal to avoid that. The problem seems to be in the coerce: method, which reads: coerce: aNumber "Note: this quick hack could be replaced by double dispatching" aNumber class = self class ifTrue: [^self class newFromNumber: aNumber scale: (scale max: aNumber scale)]. (aNumber isFraction or: [aNumber isInteger]) ifTrue: [^self class newFromNumber: aNumber scale: scale]. ^aNumber I guess I could override coerce:, but that seems wrong. So my question to the smalltalk gods on the list is: Could this be fixed with double dispatching as the comment sort of suggests, and would it be a useful thing to do?

Sept. 27, 2011

Re: [Pharo-users] [ANN] Pharo Glorp port release

by Mariano Martinez Peck

> > So, thanks again to ESUG for sponsoring the project :). > > And thanks to Alan for all his help and effort in Glorp. > Guillermo, Santiago, Gisela, Mariano, Esteban and Diogenes > > -- > You received this message because you are subscribed to the Google Groups > "proyecto_relacional" group. > To post to this group, send email to proyecto_relacional(a)googlegroups.com. > To unsubscribe from this group, send email to > proyecto_relacional+unsubscribe(a)googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/proyecto_relacional?hl=en. > -- Mariano http://marianopeck.wordpress.com

Sept. 26, 2011

www.squeakdbx.org temporally moved

by Mariano Martinez Peck

Hi guys. www.squeakdbx.org was temporally moved to http://dbxtalk.smallworks.com.ar/ (thanks SmallWorks for always host our image) We didn't yet update the website to match DBXTalk project, but soon we will do it and when that happens we will register www.dbxtalk.org and shut down http://dbxtalk.smallworks.com.ar/ Cheers DBXTalk team

Sept. 26, 2011

[ANN] Pharo Glorp port release

by Guillermo Polito

Hi! We are reaaaaally happy to announce (at last) a very very stable release of the new Glorp port :D. We've done a lot to achieve the following results with Glorp: OpenDBX Oracle: - 7 errors related to Blobs, which are not supported by opendbx. - 1 failure related to timestamp cast (and I don't understand the test intention yet :P) OpenDBX MySql: - 100% green tests :D OpenDBX PostgreSQL: - 7 errors and 1 failure related to Blobs, which are not supported by opendbx (again). OpenDBX SQLite: - 6 failures related to large objects, which are not supported by opendbx (again again).. 2 (expected) failures related to times & dates. Native PostgresV2 Driver: - 2 failures with blobs So far, some FAQs: *Â¿What is the difference between this port and the old one?* Almost 4 years of work of the VW team with tons of bugfixing (see the last 4 years release notes from Glorp for more detail :P) *Â¿How can I load it?* If you want to load Glorp + OpenDBX, you can try the following: *Gofer it squeaksource: 'MetacelloRepository'; package: 'ConfigurationOfGlorpDBX'; load. (((Smalltalk at: #ConfigurationOfGlorpDBX) perform: #project) perform: #version: with: #stable) load* Also, you can try loading only Glorp (maybe because you want to integrate it with your own database driver): Gofer it squeaksource: 'MetacelloRepository'; package: 'ConfigurationOfGlorp'; load. (((Smalltalk at: #ConfigurationOfGlorp) perform: #project) perform: #version: with: #stable) load *Â¿How did we test it?* We've tested it in Pharo 1.2 and Pharo 1.3 + Jenkins CogVms. *Â¿What's coming next?* *We are working for your happiness (?).* Hehe, our next step is to release the DBXMagritte project, which aims to allow people working in the Software business to create easy CRUD -the same scaffolding idea from RoR for example- including some of the following features: - (create a class model + magritte descriptions) from a database schema - [if you already have a descripted class model] use magritte descriptions to create a database schema - use magritte descriptions to create glorp mappings And then, you can use the same descriptions for your Seaside app, or in every magritte-friend framework you like ;) So, thanks again to ESUG for sponsoring the project :). Guillermo, Santiago, Gisela, Mariano, Esteban and Diogenes

Sept. 26, 2011

Re: [Pharo-users] Is Smalltalk superior to any other technologly for the development of web and business application?

by Offray Vladimir Luna CÃ¡rdenas

Hi, On 09/23/11 15:32, Marcus Denker wrote: > > On Sep 23, 2011, at 10:11 PM, Miguel Moquillon wrote: > >> Just a link to an interesting post: >> http://futuremint.com/smalltalk-and-seaside-versus-ruby-and-rails-i >> >> Enjoy reading ;-) >> > > The only problem is that the post is already old and he is now back using > Ruby... > > http://futuremint.com/once-again-enjoying-ruby > > (and even that post is old) > > Marcus > Well it seems that Dave has and enjoyable experience in this vs thing most of the time [1][2] until he hits metaprogramming, as he says: "I'm pretty tired of everything being a "pattern" in Smalltalk. Metaprogramming can be done with Smalltalk but its more tedious than Ruby because there is no good way to explicitly show the logic you're using, and you need a class for everything. But that'll be in another post soon" and: "You can dynamically create classes & methods in Smalltalk, but most metaprogramming I've seen and made isn't so much programming as just complicated class lookup & method dispatching. Typically one would outline some logic in the doesNotUnderstand: method that does method dispatch to other methods, however those method names are up to you to name. So your method names end up being programming by convention if you want the names to clue you in on anything. You also have method protocols, but I've found those are typically out of sync with the latest updates in my code and other libraries I've used" [1] http://futuremint.com/caching-in-seaside-vs-rails [2] http://futuremint.com/refactoring-smalltalk-is-easier-than-refactor As a newbie that's way too advanced for me, but, because we need to manage several projects with Redmine[3] I ended reading a little of Ruby[4] and I really enjoyed the similarities and differences with Smalltalk. So this thread comes in a good timing for me. [3] http://www.redmine.org/ [4] http://mislav.uniqpath.com/poignant-guide/book/ My personal learning experience with Smalltalk went from teaching introductory programming with Etoys, Bots Inc, to Pharo to Seaside. In this travel, I found another apps and ways, but most of the time I return to Smalltalk even if I'm still a newbie after several years of being around. And as a newbie, when I found post like David's I ask myself "what keeps me in Smalltalk? why, when I think in learning programming, I think in learning it in Smalltalk, after all this years, instead of more popular ones?" and for me, the answer is the community and the kind of cohesive, coherent and self contained experience of programming in Smalltalk vs programming in anything else. Still I would like to see the flexibility of python's syntax in the ways of expressing a program vs "everything is an object and you can't cheat" --in python you can and in fact that keep me away of the Smalltalk language a lot of time. Meanwhile, trying to spread the word about Smalltalk here (in BogotÃ¡, Colombia) is about building things with it that can be not be build so easily/coherently with other things. I'm thinking in building a "pocket web experience", something that you can keep in a USB drive in your pocket, connect to any computer on Mac/Linux/Windows everywhere and let you post your content, keep it with you, synchronize with your on-line hosting (may be on seasidehosting.st or smallharbour.org) and share and talk about it using social networks (but without depend on them). People here like this idea, but they ask me if is possible to make something like things you do with XDV/Deliverance[5][6][7] and, as a newbie, I have no clue... by the way, is possible? [5] http://www.slideshare.net/spliter/from-design-to-plone-site-xdvdriven-plone… [6] http://www.slideshare.net/Jazkarta/easier-and-faster-plone-theming-with-del… [7] http://laplone.org/presentations/deliverance-vs-xdv-wpd2010.pdf Anyway I just want to share some thoughts and questions about what this thread brings to my mind, but this post is getting too long, so thanks for listening and for the teaching. Cheers, Offray

Sept. 25, 2011

Re: [Pharo-users] Pharo Sprint November 2011 - Noviembre 2011 @ Smalltalks 2011

by StÃ©phane Ducasse

Great initiative :) Stef On Sep 23, 2011, at 10:44 PM, Guillermo Polito wrote: > Hi! > > I'm gathering the attendants the Pharo Sprint the day before the Smalltalks2011 in Universidad Nacional de Quilmes, so we can guess the space and other requirements needed. If you are attending, please fill the form below :). > > Estoy juntando a la gente que quiera participar del Pharo Sprint el dÃa previo a la Smalltalks, en la Universidad Nacional de Quilmes. Si queres participar, completÃ¡ el formulario de abajo. > > Gracias, Thanks! > Guille > > > Si tienes problemas para visualizar o enviar este formulario, puedes rellenarlo online: > https://spreadsheets.google.com/spreadsheet/viewform?formkey=dHlKdUdvYnF3c3… > > Pharo Sprint November 2011 - Noviembre 2011 > > > I will attend to the Pharo Sprint on november 2 of 2011, from 2pm to 8pm, at Universidad Nacional de Quilmes, the day previous to the conference. AsistirÃ© al Pharo Sprint del miÃ©rcoles 2 de noviembre de 2011, desde las 14:00 a las 20:00, en la UNQui, dÃa previo a la conferencia. > > > First and Last Name - Nombre y Apellido * > > > Email * > > > > Con la tecnologÃa de Google Docs > Informar sobre abusos - Condiciones del servicio - Otros tÃ©rminos > >

Sept. 24, 2011

Pharo Sprint November 2011 - Noviembre 2011 @ Smalltalks 2011

by Guillermo Polito

Hi! I'm gathering the attendants the Pharo Sprint the day before the Smalltalks2011 in Universidad Nacional de Quilmes, so we can guess the space and other requirements needed. If you are attending, please fill the form below :). Estoy juntando a la gente que quiera participar del Pharo Sprint el dÃa previo a la Smalltalks, en la Universidad Nacional de Quilmes. Si queres participar, completÃ¡ el formulario de abajo. Gracias, Thanks! Guille Si tienes problemas para visualizar o enviar este formulario, puedes rellenarlo online: https://spreadsheets.google.com/spreadsheet/viewform?formkey=dHlKdUdvYnF3c3… Pharo Sprint November 2011 - Noviembre 2011 I will attend to the Pharo Sprint on november 2 of 2011, from 2pm to 8pm, at Universidad Nacional de Quilmes, the day previous to the conference. AsistirÃ© al Pharo Sprint del miÃ©rcoles 2 de noviembre de 2011, desde las 14:00 a las 20:00, en la UNQui, dÃa previo a la conferencia. First and Last Name - Nombre y Apellido * Email * Con la tecnologÃa de Google Docs <http://docs.google.com> Informar sobre abusos<https://spreadsheets.google.com/spreadsheet/reportabuse?formkey=dHlKdUdvYnF…>- Condiciones del servicio <http://www.google.com/accounts/TOS> - Otros tÃ©rminos<http://www.google.com/google-d-s/terms.html>

Sept. 23, 2011