Add get_custom_metadata to CustomMetadataCache

Author: ErnestoLoma

.gitignore

@@ -50,3 +50,4 @@ wheels/
 .installed.cfg
 *.egg
 *.DS_Store
+examples/

pyatlan/cache/custom_metadata_cache.py

@@ -1,10 +1,11 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright 2022 Atlan Pte. Ltd.
 import json
-from typing import Optional
+from typing import Any, Optional
 
 from pyatlan.client.atlan import AtlanClient
 from pyatlan.error import LogicError, NotFoundError
+from pyatlan.model.core import BusinessAttributes
 from pyatlan.model.enums import AtlanTypeCategory
 from pyatlan.model.typedef import AttributeDef, CustomMetadataDef
 
@@ -202,3 +203,30 @@ def get_attributes_for_search_results(cls, set_name: str) -> Optional[list[str]]
             cls._refresh_cache()
             return cls._get_attributes_for_search_results(set_id)
         return None
+
+    @classmethod
+    def get_custom_metadata(
+        cls,
+        name: str,
+        asset_type: type,
+        business_attributes: Optional[dict[str, Any]] = None,
+    ) -> BusinessAttributes:
+        type_name = asset_type.__name__
+        ba_id = cls.get_id_for_name(name)
+        if ba_id is None:
+            raise ValueError(f"No custom metadata with the name: {name} exist")
+        for a_type in CustomMetadataCache.types_by_asset[type_name]:
+            if (
+                hasattr(a_type, "_meta_data_type_name")
+                and a_type._meta_data_type_name == name
+            ):
+                break
+        else:
+            raise ValueError(f"Custom metadata {name} is not applicable to {type_name}")
+        if ba_type := CustomMetadataCache.get_type_for_id(ba_id):
+            return (
+                ba_type(business_attributes[ba_id])
+                if business_attributes and ba_id in business_attributes
+                else ba_type()
+            )
+        raise ValueError(f"Custom metadata {name} is not applicable to {type_name}")

tests/integration/custom_metadata_test.py

@@ -116,3 +116,17 @@ def test_custom_metadata_has_human_readable_properties(client: AtlanClient):
     assert anomalo.validation_rules_details is None
     monte_carlo = table.get_business_attributes("Monte Carlo")
     assert monte_carlo is not None
+
+
+def test_get_custom_metadata():
+    custom_metadata = CustomMetadataCache.get_custom_metadata(
+        name="RACI", asset_type=Table
+    )
+    assert custom_metadata is not None
+
+
+def test_get_custom_metadata_when_name_is_invalid_then_raises_value_error():
+    with pytest.raises(
+        ValueError, match="No custom metadata with the name: Bogs exist"
+    ):
+        CustomMetadataCache.get_custom_metadata(name="Bogs", asset_type=Table)