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

Documentation on Traits

by Konrad Hinsen

Dear Pharo experts, Is there any documentation on traits as implemented in Pharo 7? It's easy to find discussions about the trait feature over the years, plus slides and related stuff, but I am not sure what the current actually implemented version is. I did manage to write and use a first trait (https://github.com/khinsen/EqualityThroughVariablesTrait) but there seem to be more advanced features such as slots that I don't know anything about. Cheers, Konrad.

Jan. 9, 2019

Re: [Pharo-users] Updating singletons

by Konrad Hinsen

Hi Steffen, > However, there is another fun possibility to figure out that a change > happened that does not involve configuration - though, a bit hacky. ;-) > You could write the accessor method such that it recompiles itself with > the first access after loading new code. For example: > >> Singleton>>uniqueInstance >> instance := self class new. >> self class compile: 'uniqueInstance ^instance'. >> ^instance If I understand this correctly, it replaces the uniqueInstance method by another one that returns the singleton instance. And when the code is reloaded, it's the above method that is reinstated, to be used just once. Neat! Thanks, Konrad.

Jan. 9, 2019

NeoJSON Custom Mapping Question

by Eric Gade

Hey guys, I'm toying with the idea of a Pharo implementation of ActivityStreams ( https://www.w3.org/TR/activitystreams-core/#introduction) which is based on a subset of JSON called JSON-LD (for "linked data"). While I do not believe this would entail creating a whole JSON-LD implementation, I do have a question about how to implement reading/writing/mapping to and from the core set of object types in the specification. I am aware that giving any class #neoJsonMapping allows one to define the specifics of the mapping to and from objects of that class (I think this is super cool, by the way). The issue with ActivityStreams objects is that the "type" of object they represent is in the JSON itself as the property "type," for example: ``` { "@context": "https://www.w3.org/ns/activitystreams", "name": "A simple note", "type": "Note", "id": "http://www.test.example/notes/1", "content": "A simple note", "replies": { "type": "Collection", "totalItems": 1, "items": [ { "name": "A response to the note", "type": "Note", "content": "A response to the note", "inReplyTo": "http://www.test.example/notes/1" } ] } } ``` This refers to a top level ActivityStream object of type "Note" which we maybe want to parse into something like `ASNote`. My core question is this: how can we get a NeoJSONReader to determine which type of object to create by checking for a "type" property as soon as possible in the process? Because this property can show up in any order, we won't know what type of object to create until it is encountered. What is the best strategy there? Does the complexity suggest that we should simply parse incoming ActivityStream objects into the collection-and-dict default mapping and deal with creating the appropriate objects after that? In this case we could still use the custom mapping for the writing, which is not a problem since the "type" field will be associated with the class (ie, ASNote class >> #type will respond with 'Note' and we can go from there). Any thoughts or suggestions much appreciated! -- Eric

Jan. 8, 2019

Re: [Pharo-users] Updating singletons

by Konrad Hinsen

Dale, > Did you try what I suggested and did it solve your problem? I tried, but I see no difference. The postload method is still not executed. Konrad.

Jan. 8, 2019

Re: [Pharo-users] Change the name of the programer in the image

by Alidra Abdelghani

Thank you guys for your answers. I didn't know about the Author class and I dont think I would have figured it out :) I did not notice neither that moving the image resets the author. I assume that it does not work when the image is moved in the same path in a different machine. I now know also that everything is in the changes file. I guess there are no security mechanism to avoid bad manipulation of such data (but I understand that this is not really useful elsewhere than in a classroom environment :)) Thanks again Abdelghani > > On 07 Jan 2019, at 10:08 am, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > But also, it should ask it again each time image changes position (something that I deeply hate, but can be useful in this situation :P) > > Esteban > >> On 7 Jan 2019, at 09:02, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >> >> I would guess that the way to do that is >> >> Author reset >> >>> On 5 Jan 2019, at 20:16, Alidra Abdelghani via Pharo-users <pharo-users(a)lists.pharo.org> wrote: >>> >>> >>> From: Alidra Abdelghani <alidrandco(a)yahoo.fr> >>> Subject: Change the name of the programer in the image >>> Date: 5 January 2019 at 20:16:22 GMT+1 >>> To: pharo-users(a)lists.pharo.org >>> >>> >>> Hi, >>> >>> In a fresh Pharo image, when you edit your first method the system asks you for your name. >>> Sometimes, I share some images with my students so I wonder if it is possible for them to enter their name instead of mine when they edit their own code? >>> >>> Thanks in advance >>> Abdelghani >>> >>> >>> >>> >> >> >

Jan. 7, 2019

Re: [Pharo-users] Change the name of the programer in the image

by Alidra Abdelghani

Thank you guys for your answers. I didn't know about the Author class and I dont think I would have figured it out :) I did not notice neither that moving the image resets the author. I assume that it does not work when the image is moved in the same path in a different machine. I now I know also that everything is in the changes file. I guess there are no security mechanism to avoid bad manipulation of such data (but I understand that this is not really useful elsewhere than in a classroom environment :)) Thanks again Abdelghani > > On 07 Jan 2019, at 10:08 am, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > But also, it should ask it again each time image changes position (something that I deeply hate, but can be useful in this situation :P) > > Esteban > >> On 7 Jan 2019, at 09:02, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >> >> I would guess that the way to do that is >> >> Author reset >> >>> On 5 Jan 2019, at 20:16, Alidra Abdelghani via Pharo-users <pharo-users(a)lists.pharo.org> wrote: >>> >>> >>> From: Alidra Abdelghani <alidrandco(a)yahoo.fr> >>> Subject: Change the name of the programer in the image >>> Date: 5 January 2019 at 20:16:22 GMT+1 >>> To: pharo-users(a)lists.pharo.org >>> >>> >>> Hi, >>> >>> In a fresh Pharo image, when you edit your first method the system asks you for your name. >>> Sometimes, I share some images with my students so I wonder if it is possible for them to enter their name instead of mine when they edit their own code? >>> >>> Thanks in advance >>> Abdelghani >>> >>> >>> >>> >> >> >

Jan. 7, 2019

Re: [Pharo-users] Updating singletons

by Dale Henrichs

Konrad, Did you try what I suggested and did it solve your problem? Dale On 1/5/19 2:45 AM, Konrad Hinsen wrote: > Dale, > >> This looks like a case where you are using a metadata-less repository >> ... if so you, should add the following method to your baseline class: > Sorry, that's way above my understanding of baselines and repository > handling in general. I started from > > https://github.com/pharo-open-documentation/pharo-wiki/blob/master/General/… > > and adapted the examples there to my own situation, my project being > hosted on GitHub: > > https://github.com/khinsen/leibniz-pharo/ > >> This mod will cause packages to be unconditionally loaded ... Monticello >> does a definition comparison on package load so only changed definitions >> are loaded into the image ... > I'd say that a new dependency should be treated like a changed one, but > again I am still very much lost in the jungle of Monticello, Metacello, > Gofer, Iceberg, etc. It's the most opaque aspect of Pharo I have > encountered so far. > > Cheers, > Konrad.

Jan. 7, 2019

Re: [Pharo-users] [ANN] P3 version 1.1

by Tudor Girba

Excellent. In the meantime, we extended GT4P3 a bit to also navigate Schemas and Tables' structure. For this, I introduced a few classes such as Database, Schema or Table to ease the inspection and tool creation. Itâs a bit naive for now, but it works quite well. Should these be committed to the P3 directly to enable an object-oriented API for drilling through the DB? Cheers, Doru > On Jan 6, 2019, at 9:17 PM, Sven Van Caekenberghe via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > > From: Sven Van Caekenberghe <sven(a)stfx.eu> > Subject: Re: [Pharo-users] [ANN] P3 version 1.1 > Date: January 6, 2019 at 9:17:34 PM GMT+1 > To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> > > > Nice, I just added convenience methods #listDatabases #listSchemas and #listTablesInSchema: to P3Client so you should be able to make a real browser, connection >> schemas >> tables >> contents (listDatabases is not so useful since you can only connect to 1 database at a time). > >> On 6 Jan 2019, at 00:01, Tudor Girba <tudor(a)tudorgirba.com> wrote: >> >> And with a little more code, we now have a dedicated Playground form snippet that opens the database connection without requiring any Pharo code. >> >> <gt4p3-snippet.png> >> >> Cheers, >> Doru >> >> >>> On Jan 5, 2019, at 12:02 AM, Tudor Girba <tudor(a)tudorgirba.com> wrote: >>> >>> You can now query a Postgres database from the new GT. The initial code is available here: >>> https://github.com/feenkcom/gt4p3 >>> >>> It currently looks like this: >>> <gt-inspector-p3-query.png> >>> >>> Cheers, >>> Doru >>> >>> >>> >>>> On Dec 31, 2018, at 12:33 PM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >>>> >>>> Hi, >>>> >>>> I created a new release of P3, the modern, lean and mean PostgreSQL client for Pharo. >>>> >>>> https://github.com/svenvc/P3 >>>> >>>> Version 1.1 contains the following changes: >>>> >>>> - added support for Postgres Extended Query protocol (P3PreparedStatement) (thx Jan @jvdsandt) >>>> - added support for reading array type values (currently INTEGER[] FLOAT[] BOOLEAN[] TEXT[] VARCHAR[]) >>>> - added P3-Tests package and moved all tests there >>>> - more comments >>>> - more unit tests >>>> >>>> https://github.com/svenvc/P3/releases/tag/v1.1 >>>> >>>> >>>> Especially Jan's contribution adds a lot of functionality: the ability to work with prepared statements. >>>> >>>> Here is an example doing a batch insert of 100 records (which is more efficient). >>>> >>>> | client statement | >>>> >>>> client := P3Client url: 'psql://sven@localhost'. >>>> >>>> client execute: 'DROP TABLE IF EXISTS table1'. >>>> client execute: 'CREATE TABLE table1 (id SERIAL PRIMARY KEY, created_at TIMESTAMP DEFAULT NOW(), name TEXT)'. >>>> >>>> statement := client prepare: 'INSERT INTO table1 (name) VALUES ($1)'. >>>> statement executeBatch: ((1 to: 100) collect: [ :index | Array with: ('Text #', index printString) ]). >>>> >>>> client query: 'SELECT * FROM table1'. >>>> client execute: 'DROP TABLE table1'. >>>> >>>> statement close. >>>> client close. >>>> >>>> >>>> Season's Greetings to you all. >>>> >>>> Sven >>>> >>>> >>>> -- >>>> Sven Van Caekenberghe >>>> Proudly supporting Pharo >>>> http://pharo.org >>>> http://association.pharo.org >>>> http://consortium.pharo.org >>>> >>>> >>>> >>>> >>> >>> -- >>> www.feenk.com >>> >>> "What is more important: To be happy, or to make happy?" >>> >> >> -- >> www.feenk.com >> >> "Quality cannot be an afterthought." >> > > > > -- www.feenk.com "No matter how many recipes we know, we still value a chef."

Jan. 7, 2019

New invite link for Discord

by Dimitris Chloupis

If you want to join our Discord server click the following link https://discord.gg/QewZMZa

Jan. 7, 2019

Roassal Explorer

by Alan Capewell

When I use the Explorer view in Roassal, clicking on the root node causes the view to open a new panel with an inspector on the element. When I expand out the tree and click on a child element the inspector does not refresh. Is there a simple way to enable that behaviour? Kind regards Alan

Jan. 7, 2019