Merge pull request #563 from duckontheweb/change/gh-481-common-metadata

Use extension-like API for CommonMetadata

Author: Jon Duckworth

CHANGELOG.md

@@ -18,6 +18,7 @@
   Objects](https://github.com/stac-extensions/pointcloud#schema-object)
   ([#548](https://github.com/stac-utils/pystac/pull/548))
 - `to_dict` and equality definition for `extensions.item_asset.AssetDefinition` ([#564](https://github.com/stac-utils/pystac/pull/564))
+- `Asset.common_metadata` property ([#563](https://github.com/stac-utils/pystac/pull/563))
 
 ### Removed
 

pystac/__init__.py

@@ -30,14 +30,13 @@
     Extent,
     SpatialExtent,
     TemporalExtent,
-    Provider,
-    ProviderRole,
     Summaries,
 )
+from pystac.common_metadata import CommonMetadata
 from pystac.summaries import RangeSummary
-from pystac.item import Item, Asset, CommonMetadata
+from pystac.item import Item, Asset
 from pystac.item_collection import ItemCollection
-
+from pystac.provider import ProviderRole, Provider
 import pystac.validation
 
 import pystac.extensions.hooks

pystac/asset.py

@@ -1,10 +1,12 @@
 from copy import copy
 from typing import Any, Dict, List, Optional, TYPE_CHECKING, Union
 
-from pystac.utils import is_absolute_href, make_absolute_href
+from pystac import common_metadata
+from pystac import utils
 
 if TYPE_CHECKING:
     from pystac.collection import Collection as Collection_Type
+    from pystac.common_metadata import CommonMetadata as CommonMetadata_Type
     from pystac.item import Item as Item_Type
 
 
@@ -94,11 +96,11 @@ def get_absolute_href(self) -> Optional[str]:
             str: The absolute HREF of this asset, or None if an absolute HREF could not
                 be determined.
         """
-        if is_absolute_href(self.href):
+        if utils.is_absolute_href(self.href):
             return self.href
         else:
             if self.owner is not None:
-                return make_absolute_href(self.href, self.owner.get_self_href())
+                return utils.make_absolute_href(self.href, self.owner.get_self_href())
             else:
                 return None
 
@@ -145,6 +147,12 @@ def clone(self) -> "Asset":
             extra_fields=self.extra_fields,
         )
 
+    @property
+    def common_metadata(self) -> "CommonMetadata_Type":
+        """Access the asset's common metadata fields as a
+        :class:`~pystac.CommonMetadata` object."""
+        return common_metadata.CommonMetadata(self)
+
     def __repr__(self) -> str:
         return "<Asset href={}>".format(self.href)
 

pystac/collection.py

@@ -1,6 +1,5 @@
 from copy import deepcopy
 from datetime import datetime
-from enum import Enum
 from pystac.errors import STACTypeError
 from typing import (
     Any,
@@ -34,6 +33,7 @@
 
 if TYPE_CHECKING:
     from pystac.item import Item as Item_Type
+    from pystac.provider import Provider as Provider_Type
 
 T = TypeVar("T")
 
@@ -409,108 +409,6 @@ def from_items(
         return Extent(spatial=spatial, temporal=temporal, extra_fields=extra_fields)
 
 
-class ProviderRole(str, Enum):
-    """Enumerates the allows values of the Provider "role" field."""
-
-    LICENSOR = "licensor"
-    PRODUCER = "producer"
-    PROCESSOR = "processor"
-    HOST = "host"
-
-
-class Provider:
-    """Provides information about a provider of STAC data. A provider is any of the
-    organizations that captured or processed the content of the collection and therefore
-    influenced the data offered by this collection. May also include information about
-    the final storage provider hosting the data.
-
-    Args:
-        name : The name of the organization or the individual.
-        description : Optional multi-line description to add further provider
-            information such as processing details for processors and producers,
-            hosting details for hosts or basic contact information.
-        roles : Optional roles of the provider. Any of
-            licensor, producer, processor or host.
-        url : Optional homepage on which the provider describes the dataset
-            and publishes contact information.
-        extra_fields : Optional dictionary containing additional top-level fields
-            defined on the Provider object.
-    """
-
-    name: str
-    """The name of the organization or the individual."""
-
-    description: Optional[str]
-    """Optional multi-line description to add further provider
-    information such as processing details for processors and producers,
-    hosting details for hosts or basic contact information."""
-
-    roles: Optional[List[ProviderRole]]
-    """Optional roles of the provider. Any of
-    licensor, producer, processor or host."""
-
-    url: Optional[str]
-    """Optional homepage on which the provider describes the dataset
-    and publishes contact information."""
-
-    extra_fields: Dict[str, Any]
-    """Dictionary containing additional top-level fields defined on the Provider
-    object."""
-
-    def __init__(
-        self,
-        name: str,
-        description: Optional[str] = None,
-        roles: Optional[List[ProviderRole]] = None,
-        url: Optional[str] = None,
-        extra_fields: Optional[Dict[str, Any]] = None,
-    ):
-        self.name = name
-        self.description = description
-        self.roles = roles
-        self.url = url
-        self.extra_fields = extra_fields or {}
-
-    def to_dict(self) -> Dict[str, Any]:
-        """Generate a dictionary representing the JSON of this Provider.
-
-        Returns:
-            dict: A serialization of the Provider that can be written out as JSON.
-        """
-        d: Dict[str, Any] = {"name": self.name}
-        if self.description is not None:
-            d["description"] = self.description
-        if self.roles is not None:
-            d["roles"] = self.roles
-        if self.url is not None:
-            d["url"] = self.url
-
-        d.update(self.extra_fields)
-
-        return d
-
-    @staticmethod
-    def from_dict(d: Dict[str, Any]) -> "Provider":
-        """Constructs an Provider from a dict.
-
-        Returns:
-            Provider: The Provider deserialized from the JSON dict.
-        """
-        return Provider(
-            name=d["name"],
-            description=d.get("description"),
-            roles=d.get(
-                "roles",
-            ),
-            url=d.get("url"),
-            extra_fields={
-                k: v
-                for k, v in d.items()
-                if k not in {"name", "description", "roles", "url"}
-            },
-        )
-
-
 class Collection(Catalog):
     """A Collection extends the Catalog spec with additional metadata that helps
     enable discovery.
@@ -583,7 +481,7 @@ def __init__(
         catalog_type: Optional[CatalogType] = None,
         license: str = "proprietary",
         keywords: Optional[List[str]] = None,
-        providers: Optional[List[Provider]] = None,
+        providers: Optional[List["Provider_Type"]] = None,
         summaries: Optional[Summaries] = None,
     ):
         super().__init__(
@@ -695,7 +593,7 @@ def from_dict(
         keywords = d.get("keywords")
         providers = d.get("providers")
         if providers is not None:
-            providers = list(map(lambda x: Provider.from_dict(x), providers))
+            providers = list(map(lambda x: pystac.Provider.from_dict(x), providers))
         summaries = d.get("summaries")
         if summaries is not None:
             summaries = Summaries(summaries)