Merge branch 'forman-82-slice_source_is_cm' into forman-82-slice_source_kwargs

Author: forman

zappend/config/config.py

@@ -122,9 +122,14 @@ def slice_engine(self) -> str | None:
 
     @property
     def slice_source(self) -> Callable[[...], Any] | None:
-        """The configured slice source type. If given, it must be
-        a callable that returns a value of type `SliceItem` or a class that is
-        derived from `SliceSource` abstract base class.
+        """A class or function that receives a
+        slice item as argument(s) and provides the slice dataset.
+
+        * If a class is given, it must be derived from `zappend.api.SliceSource`.
+        * If the function is a context manager, it must yield an `xarray.Dataset`.
+        * If a plain function is given, it must return any valid slice item type.
+
+        Refer to the user guide for more information.
         """
         return self._slice_source