replace legacy asdf extension with resource_mapping

pyproject.toml

@@ -40,7 +40,7 @@ test = [
 'tracker' = 'https://github.com/spacetelescope/stpipe/issues'
 
 [project.entry-points]
-asdf_extensions = { stpipe = 'stpipe.integration:StpipeExtension' }
+'asdf.resource_mappings' = {stpipe = 'stpipe.integration:get_resource_mappings'}
 
 [project.scripts]
 stpipe = 'stpipe.cli.main:main'

src/stpipe/config.py

@@ -214,6 +214,6 @@ def _validate_asdf(asdf_file, schema_uri):
     asdf.ValidationError
     """
     # TODO: We should add a method on AsdfFile to facilitate this:
-    schema = asdf.schema.load_schema(schema_uri, asdf_file.resolver)
+    schema = asdf.schema.load_schema(schema_uri)
     tagged_tree = asdf.yamlutil.custom_tree_to_tagged_tree(asdf_file.tree, asdf_file)
     asdf.schema.validate(tagged_tree, asdf_file, schema)

src/stpipe/integration.py

@@ -3,32 +3,15 @@
 """
 import os
 
-from asdf.extension import AsdfExtension
-from asdf import util
+from asdf.resource import DirectoryResourceMapping
 
 
 SCHEMAS_PATH = os.path.abspath(
     os.path.join(os.path.dirname(__file__), "resources", "schemas")
 )
 
 
-class StpipeExtension(AsdfExtension):
-    """
-    ASDF extension providing access to the stpipe schemas.  This
-    class is registered with the asdf_extensions entry point.
-    """
-    @property
-    def types(self):
-        # Required by the ABC but unused here
-        return []
-
-    @property
-    def tag_mapping(self):
-        # Required by the ABC but unused here
-        return []
-
-    @property
-    def url_mapping(self):
-        return [
-            ("http://stsci.edu/schemas/stpipe", util.filepath_to_url(SCHEMAS_PATH) + "/{url_suffix}.yaml"),
-        ]
+def get_resource_mappings():
+    return [
+        DirectoryResourceMapping(SCHEMAS_PATH, "http://stsci.edu/schemas/stpipe/", recursive=True),
+    ]