Generating a Tree-Editor model schema from an eCore file

[Reeze-Moodaley]

After doing some digging into the schemas used by the tree editor and our eCore file, we would like to know whether it would be possible for us to generate our model schema from our eCore file as this would save us the time of having to manually create schemas for a model as massive as ours and we would not have to repeat information that is already present within our eCore ( Such as what nodes may be children of other nodes).

Thank you in advance!

[vhemery]

You should be able to customize everything that is generated with org.eclipse.emfcloud.modelserver.jsonschema.JsonSchemaConverter and org.eclipse.emfcloud.modelserver.emf.common.SchemaController. (both UI schema and model schema)
There are default implementations binded by your Guice module, and you can override them.

[lucas-koehler]

Hi @agonzalezgaliana , the command contributions are executed during Theia's startup (as it is usually done, see Theia docs). Consequently, fetching the JSON Schema before this is likely not possible with this setup. You could get your JSONSchema and generate the creatableChildrenMap in the model service the first time its method getChildrenMapping is called (which should be by generateAddCommandDescriptions).

The remaining problem is that doing this could slow down Theia's startup time.

[agonzalezgaliana]

Hi @lucas-koehler, I see ... That's why in the Coffee Editor example "everything" in the model service is somehow hard coded. Perhaps "could" make sense, since a JSON schema is not intended to be changed that often, to hard code the map it in a TS file. However I find it "cleaner" to build that map from the JSON schema retrieved from the Model Server.

Anyways thanks for your answer!

[lucas-koehler]

@agonzalezgaliana I agree that for bigger models or ones that change more often the generation is cleaner. If you fetch it from a backend, maybe consider pre-generating the child mapping?
Another thing you can try in addition is to register the commands asynchronously to avoid slowing down start up. Here this was down with menu contributions. Might also work with the commands by making the registerCommands method async.

[agonzalezgaliana]

@lucas-koehler Thanks for the provided tips. I'll take a look on the async commands. With regards to the pre-generation of the child mapping, I'm not sure if I get what you mean. Do you mean to fetch the child mapping from a server instead of fetching the JSON schema + generating the map in the client side? May this be possible in the Model Server? How possible it would be to enhance the V1/V2 REST APIs?

[lucas-koehler]

@agonzalezgaliana Yes, that is what I meant. However, this would not solve your problem in general but just increase performance on the client side. Unfortunately, I personally don't know how to extend the Model Server REST APIs. But if you want to do that I suggest opening a separate question for that :)