appkit-launcher only injected when event_handler is present

docs/source/defining-shortcuts.md

@@ -69,21 +69,35 @@ Unix systems have the notion of MIME types, while Windows relies more on file na
 - On Windows, use `file_extensions`. Remember to add the `%1` or `%*` placeholders to your command
   so the path of the opened file(s) is passed adequately.
 - On macOS, use `CFBundleDocumentTypes`. Requires no placeholder. The opened document will be
-  automatically passed as a regular command-line argument. The file will be dispatched via events.
-  You need to define the `event_handler` field to define a logic that will forward the caught files
-  to your application (via sockets, API calls, inotify or any other inter-process communication
-  mechanism) The association happens via UTI strings (Uniform Type Identifiers). If you need UTIs
-  not defined by Apple, use the `UTImportedTypeDeclarations` field if they are provided by other
-  apps, or `UTExportedTypeDeclarations` if you are defining them yourself.
-
-:::{note}
-On macOS, this feature uses an additional launcher written in Swift to handle the Apple events.
-The Swift runtime libraries are only guaranteed to be available on macOS 10.14.4 and later.
-If you need to support older versions of macOS, you will need to instruct your users to install
-the Swift runtime libraries manually, available at https://support.apple.com/kb/DL1998.
-You can add a dependency on `__osx>=10.14.4` on your conda package if you wish to enforce it.
+  automatically passed as a regular command-line argument. The association happens via UTI strings
+  (Uniform Type Identifiers). If you need UTIs not defined by Apple, use the
+  `UTImportedTypeDeclarations` field if they are provided by other apps, or
+  `UTExportedTypeDeclarations` if you are defining them yourself.
+
+(macos-event-handler)=
+
+:::{admonition} Event handlers in macOS
+:class: note
+
+On macOS, opened files are dispatched via system events. If your application knows how to handle these events, then you don't need anything else. However, if your app is not aware of system
+events, you need to set the `event_handler` field to define a logic that will forward the caught
+files to your application (via sockets, API calls, inotify or any other inter-process communication
+mechanism). [See `event_handler` example](https://github.com/conda/menuinst/blob/e992e76/tests/data/jsons/file_types.json#L35-L57).
+
+When `event_handler` is set, `menuinst` will inject an additional launcher written in Swift to
+handle the Apple events. The Swift runtime libraries are only guaranteed to be available on macOS
+10.14.4 and later. If you need to support older versions of macOS, you will need to instruct your
+users to install the Swift runtime libraries manually, available at
+https://support.apple.com/kb/DL1998. You can add a dependency on `__osx>=10.14.4` on your conda
+package if you wish to enforce it.
 :::
 
+:::{admonition} Dock blip on macOS
+:class: tip
+
+Note that setting `CFBundleTypeRole` will make the wrapper blip in the dock when the URL is
+opened. If you don't want that, do not set it.
+:::
 
 A multi-platform example:
 
@@ -147,19 +161,8 @@ shortcut.
   so the URLs are passed adequately.
 - On Windows, use `url_protocols`. Remember to add the `%1` or `%*` placeholders to your command so
   the URLs are passed adequately.
-- On macOS, use `CFBundleURLTypes`. Requires no placeholders. The URL will be dispatched via
-  events. You need to define the `event_handler` field to define a logic that will forward the
-  caught URLs to your application (via sockets, API calls, inotify or any other inter-process
-  communication mechanism). Note that setting `CFBundleTypeRole` will make the wrapper blip in the
-  dock when the URL is opened. If you don't want that, do not set it.
-
-:::{note}
-On macOS, this feature uses an additional launcher written in Swift to handle the Apple events.
-The Swift runtime libraries are only guaranteed to be available on macOS 10.14.4 and later.
-If you need to support older versions of macOS, you will need to instruct your users to install
-the Swift runtime libraries manually, available at https://support.apple.com/kb/DL1998.
-You can add a dependency on `__osx>=10.14.4` on your conda package if you wish to enforce it.
-:::
+- On macOS, use `CFBundleURLTypes`. Requires no placeholders. See
+  {ref}`relevant note in File Types <macos-event-handler>`.
 
 ```json
 {

menuinst/platforms/osx.py

@@ -312,15 +312,15 @@ def _needs_appkit_launcher(self) -> bool:
         In macOS, file type and URL protocol associations are handled by the
         Apple Events system. When the user opens on a file or URL, the system
         will send an Apple Event to the application that was registered as a handler.
-        We need a special launcher to handle these events and pass them to the
-        wrapped application in the shortcut.
+        Some apps might not have the needed listener to process the event. In that case,
+        we provide a generic one. This is decided by the presence of "event_handler".
+        If that key is absent or null, we assume the app has its own listener.
 
         See:
         - https://developer.apple.com/library/archive/documentation/Carbon/Conceptual/LaunchServicesConcepts/LSCConcepts/LSCConcepts.html  # noqa
         - The source code at /src/appkit-launcher in this repository
         """
-        needed_keys = ("CFBundleURLTypes", "CFBundleDocumentTypes")
-        return any([self.metadata.get(k) for k in needed_keys])
+        return bool(self.metadata.get("event_handler"))
 
 
 def _lsregister(*args, check=True, **kwargs):

news/183-event-handler

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* Do not inject the AppKit launcher unless `event_handler` has been set. Only affects macOS. (#179 via #183)
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>

tests/data/jsons/file_types_no_event_handler.json

@@ -0,0 +1,41 @@
+{
+    "$schema": "https://json-schema.org/draft-07/schema",
+    "$id": "https://schemas.conda.io/menuinst-1.schema.json",
+    "menu_name": "Example with file type association and no event handler (macOS only)",
+    "menu_items": [
+        {
+            "name": "FileTypeAssociationNoEventHandler",
+            "description": "Testing file type association without event handler",
+            "icon": null,
+            "command": [
+                "{{ PYTHON }}",
+                "-c",
+                "import sys, pathlib as p; p.Path(r'__OUTPUT_FILE__').write_text(sys.argv[1])"
+            ],
+            "platforms": {
+                "osx": {
+                    "command": [
+                        "bash", "-c", "nc -l 40258 > __OUTPUT_FILE__"
+                    ],
+                    "CFBundleDocumentTypes": [
+                        {
+                            "CFBundleTypeName": "org.conda.menuinst.filetype-example-no-event-handler",
+                            "CFBundleTypeRole": "Viewer",
+                            "LSItemContentTypes": ["org.conda.menuinst.main-file-util-no-event-handler"],
+                            "LSHandlerRank": "Default"
+                        }
+                    ],
+                    "UTExportedTypeDeclarations": [
+                        {
+                            "UTTypeConformsTo": ["public.data", "public.content"],
+                            "UTTypeIdentifier": "org.conda.menuinst.main-file-util-no-event-handler",
+                            "UTTypeTagSpecification": {
+                                "public.filename-extension": ["menuinst-no-event-handler"]
+                            }
+                        }
+                    ]
+                }
+            }
+        }
+    ]
+}

tests/test_api.py

@@ -43,8 +43,9 @@ def check_output_from_shortcut(
     file_to_open=None,
     url_to_open=None,
 ) -> Tuple[Path, Iterable[Path], str]:
-    assert action in ("run_shortcut", "open_file", "open_url")
+    assert action in ("run_shortcut", "open_file", "open_url", None)
 
+    output = None
     output_file = None
     abs_json_path = DATA / "jsons" / json_path
     contents = abs_json_path.read_text()
@@ -87,7 +88,7 @@ def check_output_from_shortcut(
                     cmd = [str(executable)]
                 process = logged_run(cmd, check=True)
                 output = process.stdout
-        else:
+        elif action is not None:
             if action == "open_file":
                 assert file_to_open is not None
                 with NamedTemporaryFile(suffix=file_to_open, delete=False) as f:
@@ -263,6 +264,25 @@ def test_file_type_association(delete_files):
     assert output.strip().endswith(test_file)
 
 
+@pytest.mark.skipif(sys.platform != "darwin", reason="Only run on macOS")
+@pytest.mark.skipif("CI" not in os.environ, reason="Only run on CI. Export CI=1 to run locally.")
+def test_file_type_association_no_event_handler(delete_files, request):
+    test_file = "test.menuinst-no-event-handler"
+    abs_json_path, paths, tmp_base_path, _ = check_output_from_shortcut(
+        delete_files,
+        "file_types_no_event_handler.json",
+        action=None,
+        file_to_open=test_file,
+        remove_after=False,
+    )
+    request.addfinalizer(lambda: remove(abs_json_path, base_prefix=tmp_base_path))
+    app_dir = next(p for p in paths if p.name.endswith(".app"))
+    info = app_dir / "Contents" / "Info.plist"
+    plist = plistlib.loads(info.read_bytes())
+    cf_bundle_type_name = "org.conda.menuinst.filetype-example-no-event-handler"
+    assert plist["CFBundleDocumentTypes"][0]["CFBundleTypeName"] == cf_bundle_type_name
+
+
 @pytest.mark.skipif("CI" not in os.environ, reason="Only run on CI. Export CI=1 to run locally.")
 def test_url_protocol_association(delete_files):
     url = "menuinst://test/"