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

Re: [Pharo-users] Slots vs collections

by K K Subbu

On 20/03/20 4:54 PM, N. Bouraqadi wrote: > Hi, > > Suppose I have an instance variable referencing a collection of booleans. > I want to have all elements of the collection be stored as bits. > Is there a way I can express it using slots? What do the bits represent? Is there an ordering among these booleans? You could use a Set of integers (for ordinals) or symbols (for cardinals like flags). HTH .. Subbu

March 20, 2020

Re: [Pharo-users] Json encoding

by Sven Van Caekenberghe

Hi Victor, I would first suggest you read the following two book chapters: https://ci.inria.fr/pharo-contribution/job/EnterprisePharoBook/lastSuccessf… https://ci.inria.fr/pharo-contribution/job/EnterprisePharoBook/lastSuccessf… These should explain the basics and answer a lot of your questions. Now, from a higher level, you have to understand that without an explicit mapping, arbitrary object encoding cannot work for JSON. Furthermore, since there is no type encoding in JSON, parsing back to the original types cannot happen without help, again using an explicit mapping. In Pharo/Smalltalk, contrary to Java, we are not used to full type descriptions. Both NeoJSON and STON offer lots of options to do mapping, see the links above to get started. HTH, Sven > On 20 Mar 2020, at 02:20, Vitor Medina Cruz <vitormcruz(a)gmail.com> wrote: > > Hello, > > I know two projects of json encoding/decoding â NeoJson and STON. > > In Java I have two most used ones too: Gson and Jackson. Using those I can simply pass any object and it they can convert to a json string, the former can't deal with cycles, the latter can with some little config. > > NeoJson seems to be limited to primitives, for example, in Pharo 8 I can't run > > NeoJSONWriter toString: (Date today) > > Since I got: > > NeoJSONMappingNotFound: No mapping found for Date in NeoJSONWriter > > > STON works fine with > > STON toString: (Date today). > > but fail with: > > STON toJsonString: (Date today). > > Also, STON fails if I try to serialize an object which contains an instance variable pointing to a block closure. I didn't find out how to ignore these instance variable as it is unnecessary for what I need at the moment. > > So, which lib for json or some object/string encoding/decoding should I be using on Pharo? Is there something better than those libs? Am I doing something wrong? My experience tells this should be simple, but it is not. > > Thanks in advance, > Vitor

March 20, 2020

Re: [Pharo-users] Json encoding

by PBKResearch

Vitor First clarification: There are two different serialization formats, json and STON. The content of a json file can only be number, Boolean, string, array, dictionary. STON is an extended form based on json, designed to represent (almost) any Smalltalk object. Second clarification: What are you trying to do? Do you want to serialize data for your own use, to read back into your own Pharo app? Or do you want to export data in json format, so that other users, not using necessarily using Pharo, can import it? For the first case, STON is a very flexible and convenient system. For the second case, you must stick to strict json, using only the classes allowed in json. Coming to your specific examples, Date is not a class allowed in json. This is not a limitation of NeoJson or STON, it is a limitation of the definition of json. If you want to include a Date in a json file, you must turn it into an instance of a permitted class. So you could write: STON toJsonString: Date today asString. The only complication here is, if the json is read by other users, they must understand the format generated by Date>>asString. If you are using STON to serialise objects for your own use, you may want to exclude some instvars (e.g. block closures). This is described in the class comments to the STON-Core package. You need to include a class side message #stonAllInstVarNames in the class, which lists the names of the instvars that are to be serialized. If you want to go deeper into STON, I think Sven has an article on his website telling the whole story. This maybe enough to get you started. HTH Peter Kenny From: Pharo-users <pharo-users-bounces(a)lists.pharo.org> On Behalf Of Vitor Medina Cruz Sent: 20 March 2020 01:20 To: Any question about pharo is welcome <Pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Json encoding Hello, I know two projects of json encoding/decoding â NeoJson and STON. In Java I have two most used ones too: Gson and Jackson. Using those I can simply pass any object and it they can convert to a json string, the former can't deal with cycles, the latter can with some little config. NeoJson seems to be limited to primitives, for example, in Pharo 8 I can't run NeoJSONWriter toString: (Date today) Since I got: NeoJSONMappingNotFound: No mapping found for Date in NeoJSONWriter STON works fine with STON toString: (Date today). but fail with: STON toJsonString: (Date today). Also, STON fails if I try to serialize an object which contains an instance variable pointing to a block closure. I didn't find out how to ignore these instance variable as it is unnecessary for what I need at the moment. So, which lib for json or some object/string encoding/decoding should I be using on Pharo? Is there something better than those libs? Am I doing something wrong? My experience tells this should be simple, but it is not. Thanks in advance, Vitor

March 20, 2020

Slots vs collections

by N. Bouraqadi

Hi, Suppose I have an instance variable referencing a collection of booleans. I want to have all elements of the collection be stored as bits. Is there a way I can express it using slots? This idea can be generalized to other types of slots. Noury

March 20, 2020

Json encoding

by Vitor Medina Cruz

Hello, I know two projects of json encoding/decoding â NeoJson and STON. In Java I have two most used ones too: Gson and Jackson. Using those I can simply pass any object and it they can convert to a json string, the former can't deal with cycles, the latter can with some little config. NeoJson seems to be limited to primitives, for example, in Pharo 8 I can't run NeoJSONWriter toString: (Date today) > Since I got: NeoJSONMappingNotFound: No mapping found for Date in NeoJSONWriter > STON works fine with STON toString: (Date today). > but fail with: STON toJsonString: (Date today). > Also, STON fails if I try to serialize an object which contains an instance variable pointing to a block closure. I didn't find out how to ignore these instance variable as it is unnecessary for what I need at the moment. So, which lib for json or some object/string encoding/decoding should I be using on Pharo? Is there something better than those libs? Am I doing something wrong? My experience tells this should be simple, but it is not. Thanks in advance, Vitor

March 20, 2020

Re: [Pharo-users] Morphs with Spec2

by Sven Van Caekenberghe

But I think he wants to know how he can use Spec2 to add a centred title. That should be possible without falling back to older stuff, right ? > On 19 Mar 2020, at 10:25, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > Hi, > > 1. Spec styles define a âdefaultâ font applied to all components (morphs in this case) that understand font, and if you want to change it you need to define your own style. > 2. A string morph cannot center the string (this is a morphic stuff) > > You can solve your problem by adding a PanelMorph instead a string: > > obtainSpMorphPresenterwithAStringMorph > | morph | > morph := StringMorph > contents: 'A String Morph' > font: > (LogicalFont > familyName: Smalltalk ui theme labelFont familyName > pointSize: Smalltalk ui theme labelFont pointSize + 10). > ^ SpMorphPresenter new > morph: (PanelMorph new > addMorphBack: morph; > yourself); > yourself > > > This will produce this morph: > > <Screenshot 2020-03-19 at 10.24.01.png> > > > And since I hate morphic, I will let you to fight with morph to center your sub morph ;) > > Esteban > >> On 18 Mar 2020, at 17:41, Sebastian Jordan <sebastianjmt(a)hotmail.com> wrote: >> >> >> button1 := self newButton. >

March 19, 2020

Re: [Pharo-users] Morphs with Spec2

by Esteban Lorenzano

Hi, 1. Spec styles define a âdefaultâ font applied to all components (morphs in this case) that understand font, and if you want to change it you need to define your own style. 2. A string morph cannot center the string (this is a morphic stuff) You can solve your problem by adding a PanelMorph instead a string: obtainSpMorphPresenterwithAStringMorph | morph | morph := StringMorph contents: 'A String Morph' font: (LogicalFont familyName: Smalltalk ui theme labelFont familyName pointSize: Smalltalk ui theme labelFont pointSize + 10). ^ SpMorphPresenter new morph: (PanelMorph new addMorphBack: morph; yourself); yourself This will produce this morph: And since I hate morphic, I will let you to fight with morph to center your sub morph ;) Esteban > On 18 Mar 2020, at 17:41, Sebastian Jordan <sebastianjmt(a)hotmail.com> wrote: > > > button1 := self newButton.

March 19, 2020

Re: [Pharo-users] [ANN] COVID-19 and JRMPC

by Offray Vladimir Luna CÃ¡rdenas

It will have an even more important impact: it will save lives. Take care. Stay safe. Offray On 14/03/20 12:55 p.Â m., Richard Kenneth Eng wrote: > https://smalltalk.tech.blog/2020/03/13/covid-19-and-jrmpc/Â > > This is very unfortunate. I was counting on the awards ceremony for a > great deal of PR value. > > A virtual ceremony likely wouldn't have the same impact. > > RichardÂ

March 19, 2020

Morphs with Spec2

by Sebastian Jordan

Hi everyone, I Want to use a StringMorph as a title of a UI created with Spec2. For that, I am using a SpMorhPresenter inside a SpPresenter. But the text inside the morph loses its format as it is shown in the attached image. Does anyone knows how to solve this? What I am doing wrong? It would be very appreciated. Thanks for your time. Here is the code of the example: defaultSpec ^ SpBoxLayout newVertical add: #morphLabel; add: #button1; add: #button2; yourself initializePresenters morphLabel := self obtainSpMorphPresenterwithAStringMorph. button1 := self newButton. button1 label: 'Button one'. button2 := self newButton. button2 label: 'Button two'. self focusOrder add: morphLabel; add: button1; add: button2 obtainSpMorphPresenterwithAStringMorph | morph | morph := StringMorph contents: 'A String Morph' font: (LogicalFont familyName: Smalltalk ui theme labelFont familyName pointSize: Smalltalk ui theme labelFont pointSize + 10). ^ SpMorphPresenter new morph: morph; yourself

March 18, 2020

Re: [Pharo-users] [Roassal3 Script of the day] Visualizing Coronavirus official public data

by phil＠highoctane.be

Hello, The script is failing today due to: [image: image.png] Phil á§ On Mon, Mar 16, 2020 at 7:45 PM Alexandre Bergel via Pharo-users < pharo-users(a)lists.pharo.org> wrote: > The script I provide could be easily wrapped up into some classes. Maybe I > will use it for a new tutorial. > > Alexandre > -- > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > Alexandre Bergel http://www.bergel.eu > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > > On 16-03-2020, at 12:38, HernÃ¡n Morales Durand <hernan.morales(a)gmail.com> > wrote: > > > > Thank you Alexandre, I've been asking myself how to do it in Roassal3 in > a better way as you did!! > > Cheers, > > > > HernÃ¡n > > > > El lun., 16 mar. 2020 a las 12:31, Alexandre Bergel via Pharo-users (< > pharo-users(a)lists.pharo.org>) escribiÃ³: > > Hola, > > > > Here is a script, for which I hope some of you will find useful. > > The script of today visualize the number of infected and allows for an > easily (and very basic) comparison. First, you need Roassal3 and DataFrame. > Here is the code: > > > > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > > Metacello new > > baseline: 'Roassal3'; > > repository: 'github://ObjectProfile/Roassal3'; > > load. > > Metacello new > > baseline: 'DataFrame'; > > repository: 'github://PolyMathOrg/DataFrame:v2.0/src'; > > load. > > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > > Then, evaluate the Pharo code available on: > > > > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > > https://gist.github.com/bergel/6ebcde9696ef922f2b519c56a4520bac > > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > > > > > > You should then see the following: > > <PastedGraphic-6.png> > > > > Change the names of the countries to see what you are interested in. > > > > Stay safe > > Alexandre > > -- > > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > > Alexandre Bergel http://www.bergel.eu > > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > > > > > >

March 18, 2020