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Re: [Pharo-users] Serializing to/from Json

by Larry White

Wow. Thanks for all the replies. @Bernat. I am using the SCouchDB library, but will take a look at the other one. Thanks. @Sven. I'll also take a look at that Json library. Thank you. @Markus. It has to Json, for exactly the reason that @Davorin suggests. @Francois. I'm looking at Magritte as well, but it seems a bit overwhelming for a Smalltalk noob. I may give it a try on my next project. Apologies for the naivete of the original question. It wasn't 'til I tried writing my own that I realized (doh) that you can't write something like Gson in Java without augmenting the model with type information. I assume that's how Magritte does it, since it seems to be all about meta data. On Tue, Aug 30, 2011 at 5:30 AM, Bernat Romagosa < tibabenfortlapalanca(a)gmail.com> wrote: > Without having tried them, I see there are two CouchDB projects in > squeaksource, they may handle your needs: > > http://www.squeaksource.com/SCouchDB.html > http://www.squeaksource.com/CouchDB.html > > Cheers, > > > 2011/8/30 Sven Van Caekenberghe <sven(a)beta9.be> > >> Hi Larry, >> >> On 29 Aug 2011, at 21:27, Larry White wrote: >> >> > I've tried the JSON library bundled with SCouchDB and it seems to >> automatically handle simple objects (eg, where the inst vars reference >> Strings or Numbers), but not handle more complex objects. Also, I haven't >> seen anything that de-serializes from json. >> >> There is a JSON encoder/decoder in Seaside, it is pretty standalone, see >> this recent thread: >> >> http://forum.world.st/Standalone-JSON-Package-tp3759705p3759705.html >> >> This one works very well (I am using it all the time), but only handles >> standard JSON types (follows the spec). >> >> Now, JSON objects don't hold their type or class as Smalltalk (or Java >> objects) do, they are just Dictionaries. There is no automagic solution to >> this, apart from encoding the type/class as a property, but will most >> probably not be portable across languages (java.lang.Integer for Java, >> Integer for Smalltalk), one of the strengths of JSON. >> >> So you will have to write code to convert your Person (or whatever) >> objects to/from Dictionaries and use JSON. >> >> Sven >> >> >> >> > > > -- > Bernat Romagosa. >

Aug. 30, 2011

Re: [Pharo-users] Serializing to/from Json

by Bernat Romagosa

Without having tried them, I see there are two CouchDB projects in squeaksource, they may handle your needs: http://www.squeaksource.com/SCouchDB.html http://www.squeaksource.com/CouchDB.html Cheers, 2011/8/30 Sven Van Caekenberghe <sven(a)beta9.be> > Hi Larry, > > On 29 Aug 2011, at 21:27, Larry White wrote: > > > I've tried the JSON library bundled with SCouchDB and it seems to > automatically handle simple objects (eg, where the inst vars reference > Strings or Numbers), but not handle more complex objects. Also, I haven't > seen anything that de-serializes from json. > > There is a JSON encoder/decoder in Seaside, it is pretty standalone, see > this recent thread: > > http://forum.world.st/Standalone-JSON-Package-tp3759705p3759705.html > > This one works very well (I am using it all the time), but only handles > standard JSON types (follows the spec). > > Now, JSON objects don't hold their type or class as Smalltalk (or Java > objects) do, they are just Dictionaries. There is no automagic solution to > this, apart from encoding the type/class as a property, but will most > probably not be portable across languages (java.lang.Integer for Java, > Integer for Smalltalk), one of the strengths of JSON. > > So you will have to write code to convert your Person (or whatever) objects > to/from Dictionaries and use JSON. > > Sven > > > > -- Bernat Romagosa.

Aug. 30, 2011

Re: [Pharo-users] Serializing to/from Json

by Sven Van Caekenberghe

Hi Larry, On 29 Aug 2011, at 21:27, Larry White wrote: > I've tried the JSON library bundled with SCouchDB and it seems to automatically handle simple objects (eg, where the inst vars reference Strings or Numbers), but not handle more complex objects. Also, I haven't seen anything that de-serializes from json. There is a JSON encoder/decoder in Seaside, it is pretty standalone, see this recent thread: http://forum.world.st/Standalone-JSON-Package-tp3759705p3759705.html This one works very well (I am using it all the time), but only handles standard JSON types (follows the spec). Now, JSON objects don't hold their type or class as Smalltalk (or Java objects) do, they are just Dictionaries. There is no automagic solution to this, apart from encoding the type/class as a property, but will most probably not be portable across languages (java.lang.Integer for Java, Integer for Smalltalk), one of the strengths of JSON. So you will have to write code to convert your Person (or whatever) objects to/from Dictionaries and use JSON. Sven

Aug. 30, 2011

Re: [Pharo-users] Serializing to/from Json

by Davorin Rusevljan

On Tue, Aug 30, 2011 at 10:23 AM, Marcus Denker <marcus.denker(a)inria.fr> wrote: > > Does it need to be JSON? Since CouchDB stores data in json - I guess the answer is very likely yes, since just storing serialized blobs inside CouchDB would loose all querying and indexing available. In that case some key-value store might be a better choice than CouchDB Davorin Rusevljan http://www.cloud208.com/

Aug. 30, 2011

Re: [Pharo-users] Serializing to/from Json

by Marcus Denker

On Aug 29, 2011, at 9:58 PM, Francois Stephany wrote: > > On 29/08/11 21:27, Larry White wrote: >> Hi, >> >> I'm hoping to use CouchDB for storage on a seaside application. It would >> be lovely if I didn't have to serialize/de-serialize by hand to json for >> all my persistent objects, and could use instead something like a >> smalltalk version of Google's Gson library. Is there anything like that? >> >> I've tried the JSON library bundled with SCouchDB and it seems to >> automatically handle simple objects (eg, where the inst vars reference >> Strings or Numbers), but not handle more complex objects. Also, I >> haven't seen anything that de-serializes from json. Does it need to be JSON? There is a new binary serializer: http://rmod.lille.inria.fr/web/pier/software/Fuel Marcus -- Marcus Denker -- http://marcusdenker.de

Aug. 30, 2011

Re: [Pharo-users] Serializing to/from Json

by Francois Stephany

Hi Larry, You can maybe try with Magritte ? http://forum.world.st/Magritte-gt-Json-td3727820.html should be a good starting point :) On 29/08/11 21:27, Larry White wrote: > Hi, > > I'm hoping to use CouchDB for storage on a seaside application. It would > be lovely if I didn't have to serialize/de-serialize by hand to json for > all my persistent objects, and could use instead something like a > smalltalk version of Google's Gson library. Is there anything like that? > > I've tried the JSON library bundled with SCouchDB and it seems to > automatically handle simple objects (eg, where the inst vars reference > Strings or Numbers), but not handle more complex objects. Also, I > haven't seen anything that de-serializes from json. > > Thanks much! > > Larry

Aug. 29, 2011

Serializing to/from Json

by Larry White

Hi, I'm hoping to use CouchDB for storage on a seaside application. It would be lovely if I didn't have to serialize/de-serialize by hand to json for all my persistent objects, and could use instead something like a smalltalk version of Google's Gson library. Is there anything like that? I've tried the JSON library bundled with SCouchDB and it seems to automatically handle simple objects (eg, where the inst vars reference Strings or Numbers), but not handle more complex objects. Also, I haven't seen anything that de-serializes from json. Thanks much! Larry

Aug. 29, 2011

Re: [Pharo-users] object finalization

by Igor Stasenko

Luc won the prize :) Alex, you understood almost right, except a missing part of adding an object to weak registry: obj := Object new. objExecutor := obj executor. >>> WeakRegistry default add: obj executor: objExecutor. obj := nil. Smalltalk garbageCollect. if you look at default implementation of #executor, it just does a shallow copy of receiver. This is why two lines: objExecutor := obj executor. WeakRegistry default add: obj executor: objExecutor. equivalent to just: WeakRegistry default add: obj On 26 August 2011 21:18, Luc Fabresse <luc.fabresse(a)gmail.com> wrote: > Hi Alex, > > Here what I understood: > > Â Â Â o := Object new. > Â Â Â WeakRegistry default add: o. "a shallow copy of o is registered" > Â Â Â o := nil. > Â Â Â Smalltalk garbageCollect. > Â Â Â "the shallow copy of o will receive the finalize message" > > Cheers, > > #Luc > > > > 2011/8/26 Alex Schenkman <alex(a)schenkman.info> >> >> Let's see if I get this right: >> obj := Object new. >> objExecutor := obj executor. >> obj := nil. >> Smalltalk garbageCollect. >> Will this execute the method finalize on objExecutor? >> Is this the way to use it? >> Thanks! >> >> On Friday, August 26, 2011 at 5:53 PM, Igor Stasenko wrote: >> >> On 26 August 2011 16:29, Alex Schenkman <alex(a)schenkman.info> wrote: >> >> Hi List: >> Is there a method being called right befire an object is being garbage >> collected (finalized)? >> I see toFinalizeSend:Â to: with:, but I do not see any senders. >> thanks in advance! >> >> Squeak finalization is a post-mortem finalization. The #finalize >> message are sent to executor object, >> which is often a shallow copy of the object which is died. >> >> >> -- >> Best regards, >> Igor Stasenko AKA sig. >> > > -- Best regards, Igor Stasenko AKA sig.

Aug. 26, 2011

Re: [Pharo-users] object finalization

by Luc Fabresse

Hi Alex, Here what I understood: o := Object new. WeakRegistry default add: o. "a shallow copy of o is registered" o := nil. Smalltalk garbageCollect. "the shallow copy of o will receive the finalize message" Cheers, #Luc 2011/8/26 Alex Schenkman <alex(a)schenkman.info> > Let's see if I get this right: > > obj := Object new. > objExecutor := obj executor. > obj := nil. > Smalltalk garbageCollect. > > Will this execute the method finalize on objExecutor? > Is this the way to use it? > > Thanks! > > On Friday, August 26, 2011 at 5:53 PM, Igor Stasenko wrote: > > On 26 August 2011 16:29, Alex Schenkman <alex(a)schenkman.info> wrote: > > Hi List: > Is there a method being called right befire an object is being garbage > collected (finalized)? > I see toFinalizeSend: to: with:, but I do not see any senders. > thanks in advance! > > > Squeak finalization is a post-mortem finalization. The #finalize > message are sent to executor object, > which is often a shallow copy of the object which is died. > > > -- > Best regards, > Igor Stasenko AKA sig. > > >

Aug. 26, 2011

Re: [Pharo-users] object finalization

by Alex Schenkman

Let's see if I get this right: obj := Object new. objExecutor := obj executor. obj := nil. Smalltalk garbageCollect. Will this execute the method finalize on objExecutor? Is this the way to use it? Thanks! On Friday, August 26, 2011 at 5:53 PM, Igor Stasenko wrote: > On 26 August 2011 16:29, Alex Schenkman <alex(a)schenkman.info (mailto:alex@schenkman.info)> wrote: > > Hi List: > > Is there a method being called right befire an object is being garbage > > collected (finalized)? > > I see toFinalizeSend: to: with:, but I do not see any senders. > > thanks in advance! > > Squeak finalization is a post-mortem finalization. The #finalize > message are sent to executor object, > which is often a shallow copy of the object which is died. > > > -- > Best regards, > Igor Stasenko AKA sig.

Aug. 26, 2011