TreeEditor.ModelService (@eclipse-emfcloud/theia-tree-editor) and Async

[glsp-bot]

Hello, I would like to implement the TreeEditor.ModelService (@eclipse-emfcloud/theia-tree-editor) interface using the EMF.cloud Model Server to get TypeSchema and the UiSchema.
Yet, the ModelServerClient gives me a Promise, which I can't return in getSchemaForNode and getUiSchemaForNode implementations since the method is synchronous and does not return a Promise.
Is it intentional ? (for performance reasons ?)
Could the TreeEditor.ModelService evolve to use MaybePromise (@theia/core) return types ?

I must confess I'm quite new to Typescript, so maybe there is an obvious workaround - which I don't know about - to collapse the Promise into a synchronous result or to make the method implementation asynchronous... but after asking my friend G****e, it does not look like something feasible to me.

Thanks in advance for your ligths on that matter.

original thread by Vincent HEMERY

[glsp-bot]

[Lucas Koehler]

Hello Vincent,
the methods of the TreeEditor.ModelService being synchronous is not the case due to performance issues. It was just easier and the use case of asynchronous methods did not come up, yet.
However, I think it makes sense that they could return a promise for cases like asynchronously receiving data (like in your case). Consequently, I think the ModelService can evolve to use Promise or MaybePromise as return types.

Could you open an issue in the tree editor repository: https://github.com/eclipse-emfcloud/theia-tree-editor/issues? Then you're also directly subscribed to it :)

[glsp-bot]

[Vincent HEMERY]

Thanks Lucas. I did submit eclipse-emfcloud/theia-tree-editor#21
Not sure it would be that easy though. As stated in the issue itself, I found drawbacks where a caller of the interface itself implements a synchronous interface from @theia/core ...
So we may have some incompatibilities here.

[glsp-bot]

[Lucas Koehler]

Thanks! Yea, I suppose it won't be trivial to implement this. So I cannot guarantee when we might get to implementing it. Of course, if you want to provide a PR, I'll gladly review it and answer further questions that might occur during implementation :)