Issue464 cube metadata

[VictorVerhaert]

from issue #464

[VictorVerhaert]

openeo-python-client/openeo/metadata.py

Lines 231 to 242 in 498c4c7

	def _clone_and_update(
	self, metadata: dict = None, dimensions: List[Dimension] = None, **kwargs
	) -> CubeMetadata: # python >= 3.11: -> Self to be more correct for subclasses
	"""Create a new instance (of same class) with copied/updated fields."""
	# TODO: do we want to keep the type the same or force it to be CubeMetadata?
	# this method is e.g. used by reduce_dimension, which should return a CubeMetadata
	# If adjusted, name should be changed to e.g. _create_updated
	# Alternative is to use an optional argument to specify the class to use
	cls = type(self)
	if dimensions == None:
	dimensions = self._dimensions
	return cls(metadata=metadata or self._orig_metadata, dimensions=dimensions, **kwargs)

Currently functionality does not change due to this function.
As this function checks the type and returns an object of the same class, functions like reduce_dimension (who use this function to update a metadata object) will still return a CollectionMetadata object if that was the original object.

Changing this to return a CubeMetadata changes functionality and fails some existing tests.

An alternative is to provide an optional argument to set the expected returned class, however this feels more like a quick fix and might be confusing in the future.

[soxofaan]

some initial comments

[soxofaan]

Currently functionality does not change due to this function.

I think it's fine to keep the original type of the metadata, that will indeed avoid breakage at other places.

Priority at the moment is having a base metadata class that is not implicitly tied to collection metadata (e.g. for #425 #516 #527 etc)

[VictorVerhaert]

_orig_metadata has been removed from CubeMetadata.
This causes CollectionMetadata to override the _clone_and_update method in order to preserve the orig_metadata (CollectionMetadata cannot be initiated without metadata, as it should be imo).

Unless we change _clone_and_update to always return a CubeMetadata this is the only clean solution I think.

CubeMetadata tests still need to be written.

[soxofaan]

some quick notes

[VictorVerhaert]

TODO:

• Write test cases specific for CubeMetadata
• add type checking for different dimensions

[soxofaan]

some more notes

about test_metadata.py: be careful about adding formatting changes everywhere, that makes it hard to to find the actual things that were changed

can you also add a changelog entry?

[VictorVerhaert]

Because I changed the names of the metadata tests using CollectionMetadata to test_collectionmetadata, pre-commit refactored the whole tests causing a large diff.
I'll be more careful with this in the future.

I added an entry in the changelog and processed the last review.