[Pharo-users] Re: ReStore and storing mixed dictionaries

Hi Offray - could you try modifying SSWReStore>>createProxyForNewObject: as follows: ... table := self tableForClass: anObject class. "Add this ->” table isNil ifTrue: [ self error: 'cannot find table for ', anObject class name ]. id := table idDataField ifNotNil: [ :idDataField | idDataField accessor valueIn: anObject]. … This should change the error message to show the class of object which doesn’t have a valid table. Thanks. John

On 7 Apr 2022, at 20:29, Offray Vladimir Luna Cárdenas <offray.luna@mutabit.com> wrote:

Hi John,

Effectively ReStore didn't was storing the table object for the Nitter class. But after following your advice, i'm now able to debug both the TwitterUser and the NitterUser and obtain the same result (which makes sense as the later is inherited from the former). I think that my error was related with the definition of the synchronized tables, as I was not including explicitly the NitterUser (as I thought it would suffice with the TwitterUser one). Now it looks like this:

=== ReStore connection: (SSWSQLite3Connection on: privateDatabase fullName); connect; addClasses: { Tweet. "TwitterUser." NitterUser }; synchronizeAllClasses. === Now I can get a non nil idDataField that has the same shape when #tableForClass: and "reStoreDefinition asTableIn: ReStore" are send to TwitterUser and NitterUser. Despite of that I still get the pre-commit error: "#idDataField was send to nil". Here is a screenshot of the trace of the error and the idDataFiled seems right (or at least equal to the same field in the TwitterUser): https://i.imgur.com/F3UDC93.png <https://i.imgur.com/F3UDC93.png> For the moment, I'm planing to use an extra/temporal TwitterStoreHelper object that stores via ReStore/SQLite the objects I'm unable to store so far, but as dictionaries of key/value helper objects, where the value is just the STON serialization of the object (with the inconveniences of not being able to query it properly). For example, a 'profiles' dictionary in TwitterStoreHelper would have a Twitter/Nitter user id as a key and its Ston representation as a value. It's a temporal workaround, while I debug the above error further. I'll keep you posted on the advances and regarding the booklet, I answered you in a direct message.

Cheers,

Offray On 7/04/22 2:59, John Aspinall wrote:

...

Hi Offray,

Regarding the error, I’m guessing that ReStore doesn’t have a table object for your NitterUser class for some reason. Could you try:

myReStore tableForClass: NitterUser

…and check if this is returning nil? If so there’s an issue with creating the table for the class; you could try stepping through

NitterUser reStoreDefinition asTableIn: myReStore

...to get an idea of what’s wrong.

If this isn’t the issue please let me know.

Regarding the manual, I’ll send this to you by mail.

Cheers.

John

...

On 6 Apr 2022, at 19:48, Offray Vladimir Luna Cárdenas <offray.luna@mutabit.com <mailto:offray.luna@mutabit.com>> wrote:

Thanks Jhon, it definitively helps.

What I did was to extract some important metadata as slots of the Tweet object and made explicit the authorId, which allows me to trace tweets authorship:

=== Tweet>>class #reStoreDefinition ^ super reStoreDefinition defineAsID: #id; define: #text as: String; define: #created as: String; define: #authorId as: String; define: #timelines as: (Dictionary of: String -> String); yourself

=== Also I'm going to put in the radar the idea of storing STON strings for metadata residues.

On a related matter, I'm still unable to store properly the NitterUser, which inherits from TwitterUser into SQLite and always get a pre-commit error: "#idDataField was send to nil" when I ran "myNitterUser store". Here is my TwitterUser storing definition:

=== TwitterUser>>class #reStoreDefinition ^ super reStoreDefinition defineAsID: #id; define: #userName as: String; define: #profileImageUrl as: String; define: #profileBio as: String; "define: #createdAt as: String;" yourself.

===

What I'm missing? And more importantly: how can I debug the message, so I can asign the proper non nil object as receiver of #idDataField ?

Finally (for now ;-) ), the ReStore manual has been and important learning resource. Are you the author? And if so, would you be so kind to upload the Word source code to the Documentation/ folder in the repository under a permissive license that allow at least some format changes? We would like to add some table of contents and translate it to other formats, as we have done before with other free/libre cultural works (see [1] [2]).

[1] https://mutabit.com/repos.fossil/datafem <https://mutabit.com/repos.fossil/datafem> [2] https://mutabit.com/repos.fossil/mapeda/ <https://mutabit.com/repos.fossil/mapeda/>

Thanks,

Offray On 6/04/22 2:52, John Aspinall wrote:

...

Hi Offray,

You’re correct that ReStore can’t store that kind of mixed dictionary directly. You could store the entire STON text as one string and reify it on read, though that would mean you can’t easily query on the metadata.

A compromise solution would be to define objects and slots for the key data you’d need to query on and a STON string for the residue. This could be a better solution anyway as excessive/complex Dictionaries can be a sign that you need to define a new class/classes. For your particular project this would depend on how similar the metadata is between tweets - if there’s not much commonality then a Dictionary approach may be more appropriate.

Hope this helps,

John

...

On 5 Apr 2022, at 20:07, Offray Vladimir Luna Cárdenas <offray.luna@mutabit.com <mailto:offray.luna@mutabit.com>> wrote:

Hi all,

First of all, despite of being on a non-directly related matter with my question, congrats of Pharo 10.

We (as now we have 2 active Smalltalkers in my country... Yay!) are creating a civic tech project with Pharo/Lepiter and we would like to store some Tweet metadata coming from Nitter[1]. As we're dealing with the differences between the official Twitter API and the unofficial Nitter one, we put the metadata we need in a dictionary that has several kinds of objects, from ordered collections to other dictionaries. [1] https://nitter.net/about <https://nitter.net/about> Currently if we serialize a Tweet object in STON, we get this:

Tweet { #created : 'Tue, 05 Apr 2022 12:37:56 GMT', #text : '

[ANN] Pharo 10 Released: pharo.org/news/pharo10-relea… <https://pharo.org/news/pharo10-released>\n', #id : '1511322244353597443', #user : NitterUser { #userName : 'pharoproject', #profileImageUrl : URL [ 'http://nitter.42l.fr/pic/pbs.twimg.com/profile_images/541743734/icone-pharo-... <http://nitter.42l.fr/pic/pbs.twimg.com/profile_images/541743734/icone-pharo-...>' ] }, #metadata : { 'queries' : OrderedCollection [ { 'date' : DateAndTime [ '2022-04-05T13:36:58.546011-05:00' ], 'parameters' : 'https://nitter.42l.fr/pharoproject <https://nitter.42l.fr/pharoproject>' } ], 'timelines' : { 'pharoproject' : '1511048498703126529' } } } As you can see, the metadata slot contains a dictionary with mixed classes of objects. But I read in the ReStore manual[2] (pg 14):

"""

Like other collections, the class of elements for both key and value can be any other persistent class, and will be the same for all elements of that collection (except in the case of inheritance). """ So, is ReStore unable to store metadata dictionaries like the one described in the previous STON code? if this is possible, how can I define it in the Tweet class>>reStoreDefinition? For the moment, I'm going to create a explicit "timelines" slot to store what was being stored at the #timelines key of the metadata dictionary. But, as metadata increases, instead of moving variables previously inside of a dictionary as explicit slots of an object, I think that having a explicit way of storing dictionaries with different kinds of objects, in contrast with only uniform ones, would be needed (but I don't know if this is in the design scope of ReStore).

BTW, Lepiter has allow us to build a pretty fluent interface to browser Twitter/Nitter profiles and messages. Here it is how such UI looks for browsing last @pharoproject tweets:

https://i.imgur.com/bxFze1g.png <https://i.imgur.com/bxFze1g.png> Any help on how to use ReStore in storing mixed dictionaries is appreciated.

Thanks,

Offray