June 2020 - Pharo-users - lists.pharo.org

UK Smalltalk User Group Meeting - Wednesday, June 24th
by Giovanni Corriga June 8, 2020

June 8, 2020

The next meeting of the UK Smalltalk User Group will be on Wednesday, June 24th. Fabio Niephaus (https://fniephaus.com) will talk to us about TruffleSqueak ( https://github.com/hpi-swa/trufflesqueak) a Squeak/Smalltalk VM and Polyglot Programming Environment for the GraalVM (https://www.graalvm.org) He is a Ph.D. student within the Software Architecture Group ( https://hpi.de/swa) at the Hasso Plattner Institute, University of Potsdam, Germany. He has strong interests in dynamic programming languages, virtual execution environments, and software development tools. Fabio will talk about the motivation for his research in the field of Polyglot Programming. With a live demo, he will show how TruffleSqueak can be used as a polyglot IDE for other languages such as Java, Javascript, Python, R, or Ruby. He will also introduce us to the GraalVM ecosystem and discuss his experience in writing a Smalltalk VM in Truffle, GraalVM's language implementation framework. Given the current COVID-19 restrictions, this will be an online meeting. If you'd like to join us, please sign up in advance at the meeting Meetup's page https://www.meetup.com/UKSTUG/events/cbklbrybcjbgc/ to obtain the meeting details. See you there!

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Willow selections
by TomaÅ¾ Turk June 8, 2020

June 8, 2020

Hi, when using selection components in Willow (like single and multiple selection lists), should #currentSelection and #currentSelectionIfNone: be called only within their own affordances? If I use these messages from onTrigger evaluate: of other components (e. g. buttons), then I don't get any selected object back. Thanks and best wishes, Tomaz

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Few newbie questoins about Pharo/Smalltalk capabilities
by gustav_m June 8, 2020

June 8, 2020

Hello! I don't know if this is a good place to ask this kind of questions, but I haven't found other places where Smalltalk/Pharo experts hang out. I'm a designer and unfortunately I know nothing about programming and computation. I'm trying to change this right now. I'm looking for suitable technology to learn and so far Pharo/Smalltalk looks very promising. To be honest, it looks way too good to be true. And that's why I'm here, asking you guys to disillusion me. I work in a small department of a large company (unfortunately I can't give you too much details). Part of my job is to design tools that are used by our team. Every time I come up with an idea, we need to get a programmer from other department and we work together to bring my idea to life. So it would be perfect if I could do the programming on my own. We are lucky that we are not tied to any particular technology (at least in our department, for now). Some of our tools were written in Java, some in Python. After watching this video [https://youtu.be/AnrlSqtpOkw?t=550] my imagination just went crazy. It looks like the Smalltalk system would be also a perfect tool to give presentations to my superiors. So to me Smalltalk looks like a holy grail. But again, my perception of it is probably wrong and I might be better of learning, for instance, Dart+Flutter. So here is a bunch of questions, I hope someone will find time to answer (and I do apologize in advance, as I'm sure you may find this questions infantile and annoying): 1. As a designer I'm an aesthete. Is it possible to change the look of the windows and the environment to ones liking? Or redesign the whole system to not use windows at all? How moldable the environment is? 2. How well is Smalltalk/Pharo suited to handle different graphic animation effects? As a designer I like to use animations to cue users. What about sound effects? Also, as a hobby I'd like to try some (3.) generative art and (4.) agent based modeling. Is Pharo suitable for this kind of things? >From what I saw and read it may be good choice for ABM, but some people cry about Smalltalk being slow. So maybe I'd be wiser to learn Processing (for 3) and NetLogo (for 4) instead. This would be unfortunate as these are two another technologies to learn. 5. And the last question- as I skimmed through "Blue Book" I found so called "Pen" class. However, it looks like it's missing in Pharo. Was it removed? And if so, why? I find the language itself, and especialy its minimalism/simplicity, so elegant, that I'm thinking of printing the famous "postcard example" and hanging it on a wall. The whole system, however, is humongous! It looks like learning (to be albe to do anything interesting and non-trivial) will take ages. So, what do you think? Should I invest my time here? Or is there a different technology that I should consider? Gustav -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

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Youtube REST API?
by StÃ©phane Ducasse June 8, 2020

June 8, 2020

Hello Does any of you already used the youtube REST API? S. -------------------------------------------- StÃ©phane Ducasse http://stephane.ducasse.free.fr / http://www.pharo.org 03 59 35 87 52 Assistant: Aurore Dalle FAX 03 59 57 78 50 TEL 03 59 35 86 16 S. Ducasse - Inria 40, avenue Halley, Parc Scientifique de la Haute Borne, BÃ¢t.A, Park Plaza Villeneuve d'Ascq 59650 France

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Roassal 0.9.1 is out!
by Alexandre Bergel June 6, 2020

June 6, 2020

Hello, Roassal3 is an agile visualization engine for Pharo 8 and Pharo 9. Roassal is made to visualize data in an interactive way data. The GitHub website is https://github.com/ObjectProfile/Roassal3 <https://github.com/ObjectProfile/Roassal3> It contains tutorials and many documentations. We are happy to announce a new version of Roassal3, 0.9.1. Here is a summary of the release description: -=-=-=-=-=-= This version 0.9.1 improves Roassal3 in many different aspects. Here are the most relevants: â¢ A lot of class and method comments â¢ Improvement of the animation capabilities â¢ Improvement of Chart, the charting library â¢ Better highlighting mechanism â¢ Added some tests that check for the dependencies of Roassal3, just to make sure we do not introduce an unwanted dependency â¢ Improvement of the popup â¢ Better search in canvas capabilities â¢ Improvement of the force based layout â¢ Improvement of the stroke lines â¢ Many many more bugs fixes and small improvements... -=-=-=-=-=-= We would to thank everybody for making this to happen. You truly Rock! Cheers, Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

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shape file reading
by Baveco, Hans June 6, 2020

June 6, 2020

Hi Hernan I downloaded this shapefile directly via the browser. Indeed it wonât load, the type of shape file returned is self longAt: 33 bigEndian: false -> 577660194 where it should have answered an Integer between 0 and 31 shapeType "position 32, Integer between 0 and 31, Little Endian" ^shpBytes longAt: 33 bigEndian: false No idea what could be the cause â apparently the header of the file (the first 100 bytes) is not ok... Hans You mean some types are missing? Because I get this error when I try to read some SHP files: "Types > 20 are not yet accounted for" I wrote this script to reproduce: | shpE legend urlRoot urlESRIFilePrefix urlESRIFileShp urlPath response fileRef | " Download Shapefile resources " urlRoot := 'https://github.com/nvkelso/natural-earth-vector/blob/master/110m_cultural/'. urlESRIFilePrefix := 'ne_110m_populated_places'. urlESRIFileShp := urlESRIFilePrefix , '.shp'. urlPath := urlRoot , urlESRIFilePrefix. #('.shx' '.dbf' '.shp') do: [ : ext | | url | url := (urlPath , ext , '?raw=true') asZnUrl. (response := ZnEasy get: url) isSuccess ifFalse: [ self error: 'Cannot download file' ]. fileRef := FileSystem disk workingDirectory / (urlESRIFilePrefix , ext). fileRef writeStreamDo: [ : stream | stream nextPutAll: ((ZnByteEncoder newForEncoding: 'koi8r') decodeBytes: response contents ) ] ]. Once downloaded: | urlESRIFilePrefix urlESRIFileShp shpE | urlESRIFilePrefix := 'ne_110m_populated_places'. urlESRIFileShp := urlESRIFilePrefix , '.shp'. " Load and display it in Morphic " shpE := ShapeEnsemble fromFile: urlESRIFileShp. Maybe it's related with the fact they are encoded as koi8r? I checked with Zinc downloading first from the browser: | shpFile | shpFile := 'ne_110m_admin_0_countries.shp' asFileReference. [ shpFile binaryReadStreamDo: [ : in | (ZnCharacterEncoder detectEncoding: in upToEnd) identifier ] ] on: ZnCharacterEncodingError do: [ nil ]. Cheers, HernÃ¡n

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json-server / db.json (lowdb) / faker.js in Pharo/Zinc ?
by CÃ©drick BÃ©ler June 6, 2020

June 6, 2020

Hi Sven and all, Disclaimer: just another rather not important query (mainly for fun so donât hesitate to tell me to use the node packages instead ;-) ) To show API to students, I sometimes use https://jsonplaceholder.typicode.com. Itâs nice to play with client requests. I wonder if this would be interesting to have such tools in Pharo/Zn. Maybe it exists already somehow (for Teapot eventually) ? https://medium.com/codingthesmartway-com-blog/create-a-rest-api-with-json-s… >From their GitHub, I discovered json-server + lowdb (based on lowdash) => all nodes packages. https://github.com/typicode. It uses a db file db.json and I like such simple Â« databases Â». I know they're not real db. https://github.com/typicode/lowdb To me, it could nearly be to me an elegant personal db even if I think this is mostly used to test APIâs. Indeed, Itâs often used in conjunction with node package faker (https://github.com/marak/Faker.js/ (https://github.com/marak/Faker.js/) I would like to use that to generate static websites from Ecstatic. The placeholder default website has limitations. For instance, the following request creates a new post (but then you cannot see the result if you query for posts just after) I wanted to go past the limitation of the placeholder site (the db.json cannot be written). I can of course use the node package but you know :) Might be not so straight to port though. So there are probably three open questions in this post: 1) lowdb (I know this is not a database but itâs handy and Iâd like such usage in static website generation in conjunction with Ecstatic). Any already existing experiments maybe ? I donât think Voyage can do that. 2) the API json-server based on routes (maybe a job for Teapot) ? 3) the faker package as a fun exercice. What others think ? My priority would go for having some kind of lowdb (and Iâm pretty sure there are experiments around that - It reminds me a bit sandstonedb from Ramon http://onsmalltalk.com/sandstonedb-simple-activerecord-style-persistence-in…. Cheers, CÃ©drick

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Fwd: GIS support for Pharo
by HernÃ¡n Morales Durand June 5, 2020

June 5, 2020

---------- Forwarded message --------- De: HernÃ¡n Morales Durand <hernan.morales(a)gmail.com> Date: vie., 5 jun. 2020 a las 16:54 Subject: Re: [Pharo-users] GIS support for Pharo To: Baveco, Hans <hans.baveco(a)wur.nl> El vie., 5 jun. 2020 a las 4:27, Baveco, Hans (<hans.baveco(a)wur.nl>) escribiÃ³: > Thanks Hernan! > > > > I will try to find out what the problem is with your shape file. > > > > Btw is the code for reading/writing dbf files already available on github? > > > Yes it is: https://github.com/hernanmd/XBase Cheers, HernÃ¡n > Hans > > > > *From:* HernÃ¡n Morales Durand <hernan.morales(a)gmail.com> > *Sent:* vrijdag 5 juni 2020 0:25 > *To:* Any question about pharo is welcome <pharo-users(a)lists.pharo.org> > *Subject:* Re: [Pharo-users] GIS support for Pharo > > > > Hi Hans, > > > > > > El jue., 4 jun. 2020 a las 6:07, Baveco, Hans (<hans.baveco(a)wur.nl>) > escribiÃ³: > > Would be an interesting project.. > > An old link to possibly still useful code: > > > > http://wiki.squeak.org/squeak/3317 > > > > > > Btw the shapefile support, from the ESRI spec, was done by me and is still > available on http://www.squeaksource.com/@CUT95k_uXmPU4uXY/HCmgtrop. > > > > Thank you for the clarification (and actually sharing your work with ESRI > files!) > > I added proper credits in the Github forked repo : > https://github.com/hernanmd/Shapes > > > > I use it daily. I may have some fixes/additions, but in general the code > as provided works well (I suppose the code at smalltalkhub is still mostly > the same). Some shapefile formats are still missing, mostly because I never > encountered them.. > > > > You mean some types are missing? Because I get this error when I try to > read some SHP files: "Types > 20 are not yet accounted for" > > > > I wrote this script to reproduce: > > > > | shpE legend urlRoot urlESRIFilePrefix urlESRIFileShp urlPath response > fileRef | > > " Download Shapefile resources " > urlRoot := ' > https://github.com/nvkelso/natural-earth-vector/blob/master/110m_cultural/ > '. > urlESRIFilePrefix := 'ne_110m_populated_places'. > urlESRIFileShp := urlESRIFilePrefix , '.shp'. > urlPath := urlRoot , urlESRIFilePrefix. > > #('.shx' '.dbf' '.shp') do: [ : ext | > | url | > url := (urlPath , ext , '?raw=true') asZnUrl. > (response := ZnEasy get: url) isSuccess > ifFalse: [ self error: 'Cannot download file' ]. > fileRef := FileSystem disk workingDirectory / (urlESRIFilePrefix , ext). > fileRef writeStreamDo: [ : stream | > stream nextPutAll: ((ZnByteEncoder newForEncoding: 'koi8r') decodeBytes: > response contents ) ] ]. > > > > Once downloaded: > > > > | urlESRIFilePrefix urlESRIFileShp shpE | > urlESRIFilePrefix := 'ne_110m_populated_places'. > urlESRIFileShp := urlESRIFilePrefix , '.shp'. > > " Load and display it in Morphic " > shpE := ShapeEnsemble fromFile: urlESRIFileShp. > > > > Maybe it's related with the fact they are encoded as koi8r? > > I checked with Zinc downloading first from the browser: > > > > | shpFile | > > shpFile := 'ne_110m_admin_0_countries.shp' asFileReference. > [ shpFile binaryReadStreamDo: [ : in | > (ZnCharacterEncoder detectEncoding: in upToEnd) identifier > ] ] > on: ZnCharacterEncodingError > do: [ nil ]. > > > > > > Cheers, > > > > HernÃ¡n > > > > To read a complete shapefile one also needs to read dbf files. This was > another substantial effort > http://www.squeaksource.com/@Y4HhnL90iyA2TmAb/X0sPqshM; luckily there > was an older implementation.available to build upon. > > Not sure whether nowadays there are other ways to read/write files old > DBASE format files... > > > > Cheers, > > > > Hans Baveco > > > > > > > > > > *From:* Serge Stinckwich <serge.stinckwich(a)gmail.com> > *Sent:* donderdag 4 juni 2020 5:32 > *To:* Any question about pharo is welcome <pharo-users(a)lists.pharo.org> > *Subject:* [Pharo-users] GIS support for Pharo > > > > Dear all, > > > > there was already some discussion in the list about GIS support for Pharo > previously. > > > > Working on CORMAS multi-agent simulation platform: > https://github.com/cormas/cormas some developers feel the need to have > more GIS support for Pharo. > > > > I know of existing GIS software: > > - GeoJSON by Zweidenker: https://github.com/zweidenker/GeoJSON > > - ESRI ascii raster, done by Stephane recently: > https://github.com/Ducasse/ESRI-ASCII-Raster > > - shapefile support by Hernan: http://smalltalkhub.com/#!/~hernan/Shapes > > (to be moved to github) > > - I found this project also: http://www.squeaksource.com/gekon.html > > > > I know that Etienne Delay is also interested by GIS support and propose to > implement OpenGIS model support: > https://github.com/cormas/cormas/issues/139 > > > > Can we try to unite and maybe create a pharo-GIS organization on github to > federate our efforts? > > > Cheers, > > -- > > Serge Stinckwic > > h > > https://twitter.com/SergeStinckwich > > > >

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Re: [Pharo-users] Zinc WebSocket usage
by Erik Stel June 5, 2020

June 5, 2020

Hi Sven, (I hope this message does arrive. Sorry for the late reply. I have not been able to use the browser-interface for the ML for a number of days now. An admin could not figure this out either. So resorting to actually using a mail ;-) My architecture is one in which client and server are working fairly independent. A client or server can send the other a message whenever it wants (and there is no response expected). The client is responsible for setting up the connection and keeping it âopenâ (for the server to reach the client). When the client wants it can however disconnect and reconnect at a later time. The server will still be there (this is not visible in the example of course). Both client and server keep track of messages which canât be sent when the connection is (temporarily) down. So I have to have a separate process to read messages from the process that writes messages to the WebSocket. In a test I discovered that closing the connection from the client did not get noticed in the process doing the reading. Iâd like that process to stop running fairly directly since it is performing some additional logic. Now it takes a timeout. Closing the connection using the specified workaround does get noticed and works for me. But Iâm unsure if this is a good approach and thereâs the risk it will not work on a next update. A shorter timeout could be a solution but does mean Iâm going into a âpollingâ mode. So I think I prefer my workaround over setting a very short timeout. If you have a better solution though, please let me know. Kind regards, Erik

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Re: [Pharo-users] GIS support for Pharo
by Serge Stinckwich June 5, 2020

June 5, 2020

Hi Todd, you can join. Everyone is welcome. GDAL FFI integration would be great, but this is a lot of work I guess. Regards, On Fri, Jun 5, 2020 at 2:34 AM Todd Blanchard via Pharo-users < pharo-users(a)lists.pharo.org> wrote: > Hi Serge, > > I would love to participate in getting some GIS features into Pharo. I > think it would be a fantastic platform for GIS. > > My personal orientation is doing marine navigation (have boat with > sensors, want boat to be be smarter about navigation). > > My main interests is in being able to render S57/S52 formats. There are a > number of boat fans that balk at the price of expensive chart plotter > computers and software. > > They have given rise to some DIY stuff. Some of it just rips code > straight out of https://gdal.org - I think possibly a FFI integration > with gdal might be an amazing resource. > > I am time constrained for when I can work on this stuff but would like it > a lot if we at least had some core data types for simple things like > lat/lng, regions (polygons), and a decent general map renderer. > > Anyhow, please include me in any conversations. Navigation (both air and > sea) are two things I have an interest in. > > On Jun 3, 2020, at 8:31 PM, Serge Stinckwich <serge.stinckwich(a)gmail.com> > wrote: > > Dear all, > > there was already some discussion in the list about GIS support for Pharo > previously. > > Working on CORMAS multi-agent simulation platform: > https://github.com/cormas/cormas some developers feel the need to have > more GIS support for Pharo. > > I know of existing GIS software: > - GeoJSON by Zweidenker: https://github.com/zweidenker/GeoJSON > - ESRI ascii raster, done by Stephane recently: > https://github.com/Ducasse/ESRI-ASCII-Raster > - shapefile support by Hernan: http://smalltalkhub.com/#!/~hernan/Shapes > (to be moved to github) > - I found this project also: http://www.squeaksource.com/gekon.html > > I know that Etienne Delay is also interested by GIS support and propose to > implement OpenGIS model support: > https://github.com/cormas/cormas/issues/139 > > Can we try to unite and maybe create a pharo-GIS organization on github to > federate our efforts? > > Cheers, > -- > Serge Stinckwic > h > https://twitter.com/SergeStinckwich > > > -- Serge Stinckwic âhâ https://twitter.com/SergeStinckwich â

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