Extension/datacube - added variable property (#645)

* Extension/datacube - added variable property

* Extension/datacube - complied with pre-commit hooks

* Extension/datacube - applied suggest changes from pr #645

* Extension/datacube - applied suggest changes from pr #645

Co-authored-by: Thomas Li Fredriksen <[email protected]>

Author: thomafred

CHANGELOG.md

@@ -15,6 +15,7 @@
   for `mypy` ([#591](https://github.com/stac-utils/pystac/pull/591))
 - Links will get their `title` from their target if no `title` is provided ([#607](https://github.com/stac-utils/pystac/pull/607))
 - Relax typing on `LabelClasses` from `List` to `Sequence` ([#627](https://github.com/stac-utils/pystac/pull/627))
+- Upgraded datacube-extension to version 2.0.0 ([#645](https://github.com/stac-utils/pystac/pull/645))
 
 ### Fixed
 

docs/api.rst

@@ -362,6 +362,22 @@ AdditionalDimension
    :show-inheritance:
    :inherited-members:
 
+VariableType
+~~~~~~~~~~~~
+
+.. autoclass:: pystac.extensions.datacube.VariableType
+   :members:
+   :show-inheritance:
+   :inherited-members:
+
+Variable
+~~~~~~~~
+
+.. autoclass:: pystac.extensions.datacube.Variable
+   :members:
+   :show-inheritance:
+   :inherited-members:
+
 DatacubeExtension
 ~~~~~~~~~~~~~~~~~
 

pystac/extensions/datacube.py

@@ -17,10 +17,11 @@
 
 T = TypeVar("T", pystac.Collection, pystac.Item, pystac.Asset)
 
-SCHEMA_URI = "https://stac-extensions.github.io/datacube/v1.0.0/schema.json"
+SCHEMA_URI = "https://stac-extensions.github.io/datacube/v2.0.0/schema.json"
 
 PREFIX: str = "cube:"
 DIMENSIONS_PROP = PREFIX + "dimensions"
+VARIABLES_PROP = PREFIX + "variables"
 
 # Dimension properties
 DIM_TYPE_PROP = "type"
@@ -32,6 +33,14 @@
 DIM_REF_SYS_PROP = "reference_system"
 DIM_UNIT_PROP = "unit"
 
+# Variable properties
+VAR_TYPE_PROP = "type"
+VAR_DESC_PROP = "description"
+VAR_EXTENT_PROP = "extent"
+VAR_VALUES_PROP = "values"
+VAR_DIMENSIONS_PROP = "dimensions"
+VAR_UNIT_PROP = "unit"
+
 
 class DimensionType(str, Enum):
     """Dimension object types for spatial and temporal Dimension Objects."""
@@ -398,6 +407,102 @@ def reference_system(self, v: Optional[Union[str, float, Dict[str, Any]]]) -> No
             self.properties[DIM_REF_SYS_PROP] = v
 
 
+class VariableType(str, Enum):
+    """Variable object types"""
+
+    DATA = "data"
+    AUXILIARY = "auxiliary"
+
+
+class Variable:
+    properties: Dict[str, Any]
+
+    def __init__(self, properties: Dict[str, Any]) -> None:
+        self.properties = properties
+
+    @property
+    def dimensions(self) -> List[str]:
+        """The dimensions of the variable. Should refer to keys in the ``cube:dimensions``
+        object or be an empty list if the variable has no dimensions"""
+        return get_required(
+            self.properties.get(VAR_DIMENSIONS_PROP),
+            "cube:variable",
+            VAR_DIMENSIONS_PROP,
+        )
+
+    @dimensions.setter
+    def dimensions(self, v: List[str]) -> None:
+        self.properties[VAR_DIMENSIONS_PROP] = v
+
+    @property
+    def var_type(self) -> Union[VariableType, str]:
+        """Type of the variable, either ``data`` or ``auxiliary``"""
+        return get_required(
+            self.properties.get(VAR_TYPE_PROP), "cube:variable", VAR_TYPE_PROP
+        )
+
+    @var_type.setter
+    def var_type(self, v: Union[VariableType, str]) -> None:
+        self.properties[VAR_TYPE_PROP] = v
+
+    @property
+    def description(self) -> Optional[str]:
+        """Detailed multi-line description to explain the variable. `CommonMark 0.29
+        <http://commonmark.org/>`__ syntax MAY be used for rich text representation."""
+        return self.properties.get(VAR_DESC_PROP)
+
+    @description.setter
+    def description(self, v: Optional[str]) -> None:
+        if v is None:
+            self.properties.pop(VAR_DESC_PROP, None)
+        else:
+            self.properties[VAR_DESC_PROP] = v
+
+    @property
+    def extent(self) -> List[Union[float, str, None]]:
+        """If the variable consists of `ordinal values
+        <https://en.wikipedia.org/wiki/Level_of_measurement#Ordinal_scale>`, the extent
+        (lower and upper bounds) of the values as two-dimensional array. Use ``None``
+        for open intervals"""
+        return get_required(
+            self.properties.get(VAR_EXTENT_PROP), "cube:variable", VAR_EXTENT_PROP
+        )
+
+    @extent.setter
+    def extent(self, v: List[Union[float, str, None]]) -> None:
+        self.properties[VAR_EXTENT_PROP] = v
+
+    @property
+    def values(self) -> Optional[List[Union[float, str]]]:
+        """A set of all potential values, especially useful for `nominal values
+        <https://en.wikipedia.org/wiki/Level_of_measurement#Nominal_level>`."""
+        return self.properties.get(VAR_VALUES_PROP)
+
+    @values.setter
+    def values(self, v: Optional[List[Union[float, str]]]) -> None:
+        if v is None:
+            self.properties.pop(VAR_VALUES_PROP)
+        else:
+            self.properties[VAR_VALUES_PROP] = v
+
+    @property
+    def unit(self) -> Optional[str]:
+        """The unit of measurement for the data, preferably compliant to `UDUNITS-2
+        <https://ncics.org/portfolio/other-resources/udunits2/>` units (singular)"""
+        return self.properties.get(VAR_UNIT_PROP)
+
+    @unit.setter
+    def unit(self, v: Optional[str]) -> None:
+        if v is None:
+            self.properties.pop(VAR_UNIT_PROP)
+        else:
+            self.properties[VAR_UNIT_PROP] = v
+
+    @staticmethod
+    def from_dict(d: Dict[str, Any]) -> "Variable":
+        return Variable(d)
+
+
 class DatacubeExtension(
     Generic[T],
     PropertiesExtension,
@@ -423,8 +528,6 @@ def apply(self, dimensions: Dict[str, Dimension]) -> None:
         :class:`~pystac.Collection`, :class:`~pystac.Item` or :class:`~pystac.Asset`.
 
         Args:
-            bands : A list of available bands where each item is a :class:`~Band`
-                object. If given, requires at least one band.
             dimensions : Dictionary mapping dimension name to a :class:`Dimension`
                 object.
         """
@@ -442,6 +545,15 @@ def dimensions(self) -> Dict[str, Dimension]:
     def dimensions(self, v: Dict[str, Dimension]) -> None:
         self._set_property(DIMENSIONS_PROP, {k: dim.to_dict() for k, dim in v.items()})
 
+    @property
+    def variables(self) -> Optional[Dict[str, Variable]]:
+        """Dictionary mapping variable name to a :class:`Variable` object."""
+        result = self._get_property(VARIABLES_PROP, Dict[str, Any])
+
+        if result is None:
+            return None
+        return {k: Variable.from_dict(v) for k, v in result.items()}
+
     @classmethod
     def get_schema_uri(cls) -> str:
         return SCHEMA_URI

tests/data-files/datacube/item.json

@@ -1,7 +1,7 @@
 {
     "stac_version": "1.0.0-rc.1",
     "stac_extensions": [
-        "https://stac-extensions.github.io/datacube/v1.0.0/schema.json"
+        "https://stac-extensions.github.io/datacube/v2.0.0/schema.json"
     ],
     "id": "datacube-123",
     "type": "Feature",