What is the purpose of _create_endpoint?

[rsmith013]

While looking at #272, we are trying to find a way to have URL parameters and POST request body defined in the openAPI docs. I am having trouble understanding the code which follows _create_endpoint.

• What is its intention?
• What problem is it trying to solve?

There seems to be a link between it and **kwargs usage but can't see a reason to keep them in as query_params can be retrieved from the starlette.request object. e.g. request.query_params. We are pondering creating a PR that removes the _create_endpoint and potentially would mean that the URI classes also can go.

Simplification is probably a win but only if it doesn't remove functionality that is necessary and intentional.

[Mahir-Sparkess]

On further note: _create_endpoint can be replaced just pointing the endpoint arg to the client function as seen in this change.

This, however, does require some adjustments to the transaction base clients; removing the kwargs, adding a starlette.Request arg, adding args matching the URL parameters/endpoint as follows here.

The result in the /docs shows the endpoint with the ability to pass a URL parameter and POST request body to the function. It also shows a template item, based on the stac-pydantic model.

[geospatial-jeff]

What problem is it trying to solve?

Great question! It was initially a way of decoupling the API layer from the backend logic. FastAPI has all sorts of things like dependency injection that we want to keep separate from the backend, and much of this is tied to the use of pydantic. Now that we've moved away from pydantic (for the most part) I think it's worth considering removing _create_endpoint - and potentially the things it calls.

The one place we are still using fastapi.Depends is when injecting the starlette request model into each function call, which is required for the API to dynamically generate URLs but I think there are ways to get around this. Probably the best solution is to push dynamic link generation to the edge of the API layer so we can remove dependency injection entirely. And keep API specific things in the API layer.

[geospatial-jeff]

I want to review _create_endpoint and hopefully simplify it once #432 finished.