Is it possible to access preference values in the backend?

[rannp-toro-cloud]

Hi, I've added custom preference fields using the PreferenceContribution. In the frontend, I can retrieve the preference values using the PreferenceService, but I'm not sure if it's possible to access them in the backend.

[sdirix]

Hi @rannp-toro-cloud,

Generally speaking, preferences are a frontend concept in Theia, so there is no built-in support to access them via the backend.

Usually user actions are triggered from the frontend, so the typical pattern is that you retrieve the relevant preference values and hand them over to your backend calls as parameters.

There are some alternatives if you really need them:

• We have the concept of connection containers. If you bind a backend service within such a container, then it will be instantiated per connection (i.e. per frontend). In it you can directly access frontend services. If this is a pattern which fits your use case, then this would be a way to directly access those preferences.
• If you are just within a backend without any frontend, and you still want to access the user preferences, then you can check the location manually and just read in the JSON file.

Still, the first approach is likely the easiest one.

[msujew]

If you are just within a backend without any frontend, and you still want to access the user preferences, then you can check the location manually and just read in the JSON file.

Note that this only works for user preferences, as the backend has no idea what the current workspace folders of the respective frontend are. But my recommendation would also be to pass them into the backend via RPC.