Fix recursive search in Client.get_items

[mishaschwartz]

Related Issue(s):

• Resolves Client.get_items has surprising recursive behaviour when using the /search endpoint #798

Description:

• runs a non-recursive search when using the recursive argument is False
• no longer fails when using /search endpoint of an API that requires that at least one collection be passed as an argument (e.g. https://planetarycomputer.microsoft.com/api/stac/v1/)
• updates tests

PR Checklist:

• Code is formatted
• Tests pass
• Changes are added to CHANGELOG.md

[jsignell]

I have a few suggestions, but thank you so much for opening this PR! I think it'll be a real improvement.

[jsignell]

This seems like it would be pretty easy to do accidentally. I think I'd prefer to just let the error raise and make it a little harder to get every single item in planetary computer for instance.

[mishaschwartz]

My concern is that without something like this, many functions that call get_items simply don't work for planetary computer or similar APIs that enforce this required argument. This includes:

• Client.get_all_items,
• Client.walk,
• Client.validate_all,
• Client.describe,
• Client.make_all_asset_hrefs_relative,
• Client.make_all_asset_hrefs_absolute

Note that the spec doesn't say one way or another that these arguments must be optional so I'm guessing that planetary computer's API is still spec compliant technically. However, the examples show that a search without collections should be supported so I don't really know one way or the other how to interpret that:

https://github.com/radiantearth/stac-api-spec/blob/604ade6158de15b8ab068320ca41e25e2bf0e116/item-search/examples.md?plain=1#L27

Otherwise the only way to make this work for APIs like planetary computer is to override the Client class like:

import pystac_client

class Client(pystac_client.Client):
    def search(self, *args, **kwargs):
        if kwargs["collections"] is None:
            kwargs["collections"] = [self.id *[catalog.id for catalog, _, _ in self.walk()]]
        return super().search(*args, **kwargs)

pystac_client.client.Client = Client  # so that sub-catalogs also use the updated search method 

If that's the approach we want to go with that's fine, but maybe we should document this workaround in case users want to interact with planetary computer.

What do you think?