How should datasette.client interact with base_url

[simonw]

Refs #1023. If Datasette is running with a base_url setting and a plugin calls e.g. datasette.client.get("/-/plugins.json") what should happen?

[simonw]

I'm inclined to say that internal requests should ignore base_url - since that seems like the right thing for plugins that need to access default Datasette APIs.

The one catch here is plugins that might want to proxy the current incoming URL for some reason - where that incoming request.path could include the base_url.

Actually those should be fine - because it will have been stripped off earlier:

datasette/datasette/app.py

Lines 963 to 968 in 4f7c0eb

	async def route_path(self, scope, receive, send, path):
	# Strip off base_url if present before routing
	base_url = self.ds.config("base_url")
	if base_url != "/" and path.startswith(base_url):
	path = "/" + path[len(base_url) :]
	request = Request(scope, receive)

[simonw]

We have a solution for this now: datasette.urls from #1033 can be used by plugins to assemble the correct URLs to pass to .get() and friends.

[simonw]

Reconsidering this: I think the .get() etc methods should automatically add the base_url prefix for you, since these APIs are only intended to make internal calls.

The clincher on this is when I went to add a section to the datasette.client documentation recommending you use datasette.urls.path() for every call to them that you make.

But there's a problem: to handle table name escaping users are likely to want to use datasette.urls.table() anyway, like this:

response = await datasette.client.get(datasette.urls.table("db", "table") + ".json")

This risks adding the base_url prefix twice. Maybe the .table() method could return a string-like object that is marked as already having the base_url prefix added, so the client.get() method knows not to add it again.

[simonw]

That datasette.urls.table("db", "table") + ".json" example is bad because if the table name contains a . it should be ?_format=json instead.

Maybe .table() should have a format="json" option that knows how to do this.

[simonw]

#1041 can also benefit from the string subclass that shows that base_url has been added.