Allow overriding builtin plugins via entrypoint method. (AcademySoftwareFoundation#1389)

* Load entrypoint plugins before builtin and contrib in order to allow overriding builtin plugins.

Signed-off-by: Mark Reid <[email protected]>
Signed-off-by: Michele Spina <[email protected]>

Author: markreidvfx

src/py-opentimelineio/opentimelineio/plugins/manifest.py

@@ -202,10 +202,10 @@ def load_manifest():
 
     The order of loading (and precedence) is:
 
-       1. manifests specfied via the ``OTIO_PLUGIN_MANIFEST_PATH`` variable
-       2. builtin plugin manifest
-       3. contrib plugin manifest
-       4. ``setuptools.pkg_resources`` based plugin manifests
+       1. Manifests specified via the ``OTIO_PLUGIN_MANIFEST_PATH`` variable
+       2. Entrypoint based plugin manifests
+       3. Builtin plugin manifest
+       4. Contrib plugin manifest
     """
 
     result = Manifest()
@@ -232,32 +232,6 @@ def load_manifest():
 
             result.extend(manifest_from_file(json_path))
 
-    # the builtin plugin manifest
-    builtin_manifest_path = os.path.join(
-        os.path.dirname(os.path.dirname(inspect.getsourcefile(core))),
-        "adapters",
-        "builtin_adapters.plugin_manifest.json"
-    )
-    if os.path.abspath(builtin_manifest_path) not in result.source_files:
-        plugin_manifest = manifest_from_file(builtin_manifest_path)
-        result.extend(plugin_manifest)
-
-    # the contrib plugin manifest (located in the opentimelineio_contrib package)
-    try:
-        import opentimelineio_contrib as otio_c
-
-        contrib_manifest_path = os.path.join(
-            os.path.dirname(inspect.getsourcefile(otio_c)),
-            "adapters",
-            "contrib_adapters.plugin_manifest.json"
-        )
-        if os.path.abspath(contrib_manifest_path) not in result.source_files:
-            contrib_manifest = manifest_from_file(contrib_manifest_path)
-            result.extend(contrib_manifest)
-
-    except ImportError:
-        pass
-
     # setuptools.pkg_resources based plugins
     if pkg_resources:
         for plugin in pkg_resources.iter_entry_points(
@@ -324,6 +298,32 @@ def load_manifest():
         #        available?
         pass
 
+    # the builtin plugin manifest
+    builtin_manifest_path = os.path.join(
+        os.path.dirname(os.path.dirname(inspect.getsourcefile(core))),
+        "adapters",
+        "builtin_adapters.plugin_manifest.json"
+    )
+    if os.path.abspath(builtin_manifest_path) not in result.source_files:
+        plugin_manifest = manifest_from_file(builtin_manifest_path)
+        result.extend(plugin_manifest)
+
+    # the contrib plugin manifest (located in the opentimelineio_contrib package)
+    try:
+        import opentimelineio_contrib as otio_c
+
+        contrib_manifest_path = os.path.join(
+            os.path.dirname(inspect.getsourcefile(otio_c)),
+            "adapters",
+            "contrib_adapters.plugin_manifest.json"
+        )
+        if os.path.abspath(contrib_manifest_path) not in result.source_files:
+            contrib_manifest = manifest_from_file(contrib_manifest_path)
+            result.extend(contrib_manifest)
+
+    except ImportError:
+        pass
+
     # force the schemadefs to load and add to schemadef module namespace
     for s in result.schemadefs:
         s.module()

tests/baselines/plugin_module/otio_override_adapter.egg-info/PKG-INFO

@@ -0,0 +1,11 @@
+Metadata-Version: 1.0
+Name: otio-override-adapter
+Version: 1.0.0
+Summary: Dummy Adapter used for testing.
+Home-page: http://opentimeline.io
+Author: Contributors to the OpenTimelineIO project
+Author-email: [email protected]
+License: Modified Apache 2.0 License
+Description-Content-Type: UNKNOWN
+Description: UNKNOWN
+Platform: any

tests/baselines/plugin_module/otio_override_adapter.egg-info/entry_points.txt

@@ -0,0 +1,3 @@
+[opentimelineio.plugins]
+mock_plugin = otio_override_adapter
+

tests/baselines/plugin_module/otio_override_adapter/__init__.py

@@ -0,0 +1,12 @@
+{
+    "OTIO_SCHEMA" : "PluginManifest.1",
+    "adapters": [
+        {
+            "OTIO_SCHEMA" : "Adapter.1",
+            "name" : "cmx_3600",
+            "execution_scope" : "in process",
+            "filepath" : "adapter.py",
+            "suffixes" : ["edl"]
+        }
+    ]
+}

tests/baselines/plugin_module/otio_override_adapter/adapter.py

@@ -49,6 +49,12 @@ def setUp(self):
             "plugin_manifest.json"
         )
 
+        self.override_adapter_manifest_path = os.path.join(
+            mock_module_path,
+            "otio_override_adapter",
+            "plugin_manifest.json"
+        )
+
         # Create a WorkingSet as if the module were installed
         entries = [mock_module_path] + pkg_resources.working_set.entries
 
@@ -70,6 +76,9 @@ def tearDown(self):
         if 'otio_mockplugin' in sys.modules:
             del sys.modules['otio_mockplugin']
 
+        if 'otio_override_adapter' in sys.modules:
+            del sys.modules['otio_override_adapter']
+
     def test_detect_plugin(self):
         """This manifest uses the plugin_manifest function"""
 
@@ -91,6 +100,28 @@ def test_detect_plugin(self):
         for linker in man.media_linkers:
             self.assertIsInstance(linker, otio.media_linker.MediaLinker)
 
+    def test_overrride_adapter(self):
+        # Test that entrypoint plugins load before builtin and contrib
+        man = otio.plugins.manifest.load_manifest()
+
+        # The override_adapter creates another cmx_3600 adapter
+        adapters = [adapter for adapter in man.adapters
+                    if adapter.name == "cmx_3600"]
+
+        # More then one cmx_3600 adapter should exist.
+        self.assertTrue(len(adapters) > 1)
+
+        # Override adapter should be the first adapter found
+        manifest = adapters[0].plugin_info_map().get('from manifest', None)
+        self.assertEqual(manifest, os.path.abspath(self.override_adapter_manifest_path))
+
+        self.assertTrue(
+            any(
+                True for p in man.source_files
+                if self.override_adapter_manifest_path in p
+            )
+        )
+
     def test_pkg_resources_disabled(self):
         os.environ["OTIO_DISABLE_PKG_RESOURCE_PLUGINS"] = "1"
         import_reload(otio.plugins.manifest)
@@ -100,6 +131,10 @@ def test_pkg_resources_disabled(self):
         with self.assertRaises(AssertionError):
             self.test_detect_plugin()
 
+        # override adapter should not be loaded either
+        with self.assertRaises(AssertionError):
+            self.test_overrride_adapter()
+
         # remove the environment variable and reload again for usage in the
         # other tests
         del os.environ["OTIO_DISABLE_PKG_RESOURCE_PLUGINS"]