feat: add decorators for event handler registration

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

st3/lsp_utils/__init__.py

@@ -1,4 +1,5 @@
 from ._client_handler import ClientHandler
+from ._client_handler import as_notification_handler, as_request_handler
 from .api_wrapper_interface import ApiWrapperInterface
 from .generic_client_handler import GenericClientHandler
 from .npm_client_handler import NpmClientHandler
@@ -14,4 +15,7 @@
     'ServerResourceInterface',
     'ServerStatus'
     'ServerNpmResource',
+    # decorator-related
+    'as_notification_handler',
+    'as_request_handler',
 ]

st3/lsp_utils/_client_handler/__init__.py

@@ -1,3 +1,4 @@
+from .decorator import as_notification_handler, as_request_handler
 from LSP.plugin import __version__ as lsp_version
 
 
@@ -8,4 +9,7 @@
 
 __all__ = [
     'ClientHandler',
+    # decorator-related
+    'as_notification_handler',
+    'as_request_handler',
 ]

st3/lsp_utils/_client_handler/abstract_plugin.py

@@ -1,5 +1,6 @@
 from ..api_wrapper_interface import ApiWrapperInterface
 from ..server_resource_interface import ServerStatus
+from .decorator import HANDLER_MARKS
 from .interface import ClientHandlerInterface
 from LSP.plugin import AbstractPlugin
 from LSP.plugin import ClientConfig
@@ -12,6 +13,7 @@
 from LSP.plugin import WorkspaceFolder
 from LSP.plugin.core.rpc import method2attr
 from LSP.plugin.core.typing import Any, Callable, Dict, List, Optional, Tuple
+import inspect
 import sublime
 import weakref
 
@@ -158,4 +160,27 @@ def _upgrade_languages_list(cls, languages):
 
     def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)
-        self.on_ready(ApiWrapper(self))
+        api = ApiWrapper(self)
+        self._register_custom_server_event_handlers(api)
+        self.on_ready(api)
+
+    def _register_custom_server_event_handlers(self, api: ApiWrapperInterface) -> None:
+        """
+        Register decorator-style custom event handlers.
+
+        This method works as following steps:
+
+        1. Scan through all methods of this object.
+        2. If a method is decorated, it will has a "handler mark" attribute which is put by the decorator.
+        3. Register the method with wanted events, which are stored in the "handler mark" attribute.
+
+        :param api: The API instance for interacting with the server.
+        """
+        for _, func in inspect.getmembers(self, predicate=inspect.isroutine):
+            # client_event is like "notification", "request"
+            for client_event, handler_mark in HANDLER_MARKS.items():
+                event_registrator = getattr(api, "on_" + client_event, None)
+                if callable(event_registrator):
+                    server_events = getattr(func, handler_mark, [])  # type: List[str]
+                    for server_event in server_events:
+                        event_registrator(server_event, func)

st3/lsp_utils/_client_handler/decorator.py

@@ -0,0 +1,40 @@
+from LSP.plugin.core.typing import Any, Callable, Iterable, Union
+
+__all__ = [
+    "HANDLER_MARKS",
+    "as_notification_handler",
+    "as_request_handler",
+]
+
+# the first argument is always "self"
+T_HANDLER = Callable[[Any, Any], None]
+T_SERVER_EVENTS = Union[str, Iterable[str]]
+
+HANDLER_MARKS = {
+    "notification": "__handle_notification_events",
+    "request": "__handle_request_events",
+}
+
+
+def as_notification_handler(server_events: T_SERVER_EVENTS) -> Callable[[T_HANDLER], T_HANDLER]:
+    """ Marks the decorated function as a "notification" event handler. """
+
+    return _as_handler("notification", server_events)
+
+
+def as_request_handler(server_events: T_SERVER_EVENTS) -> Callable[[T_HANDLER], T_HANDLER]:
+    """ Marks the decorated function as a "request" event handler. """
+
+    return _as_handler("request", server_events)
+
+
+def _as_handler(client_event: str, server_events: T_SERVER_EVENTS) -> Callable[[T_HANDLER], T_HANDLER]:
+    """ Marks the decorated function as a event handler. """
+
+    server_events = [server_events] if isinstance(server_events, str) else list(server_events)
+
+    def decorator(func: T_HANDLER) -> T_HANDLER:
+        setattr(func, HANDLER_MARKS[client_event], server_events)
+        return func
+
+    return decorator

st3/lsp_utils/_client_handler/language_handler.py

@@ -1,6 +1,7 @@
 from ..api_wrapper_interface import ApiWrapperInterface
 from ..helpers import log_and_show_message
 from ..server_resource_interface import ServerStatus
+from .decorator import HANDLER_MARKS
 from .interface import ClientHandlerInterface
 from LSP.plugin import ClientConfig
 from LSP.plugin import LanguageHandler
@@ -10,6 +11,7 @@
 from LSP.plugin import Response
 from LSP.plugin.core.typing import Any, Callable, Dict, Optional
 from sublime_lib import ActivityIndicator
+import inspect
 import sublime
 
 __all__ = ['ClientHandler']
@@ -82,7 +84,9 @@ def on_start(cls, window: sublime.Window) -> bool:
         return True
 
     def on_initialized(self, client) -> None:
-        self.on_ready(ApiWrapper(client))
+        api = ApiWrapper(client)
+        self._register_custom_server_event_handlers(api)
+        self.on_ready(api)
 
     # --- ClientHandlerInterface --------------------------------------------------------------------------------------
 
@@ -144,3 +148,24 @@ def __init__(self):
         # Will be a no-op if already ran.
         # See https://github.com/sublimelsp/LSP/issues/899
         self.setup()
+
+    def _register_custom_server_event_handlers(self, api: ApiWrapperInterface) -> None:
+        """
+        Register decorator-style custom event handlers.
+
+        This method works as following steps:
+
+        1. Scan through all methods of this object.
+        2. If a method is decorated, it will has a "handler mark" attribute which is put by the decorator.
+        3. Register the method with wanted events, which are stored in the "handler mark" attribute.
+
+        :param api: The API instance for interacting with the server.
+        """
+        for _, func in inspect.getmembers(self, predicate=inspect.isroutine):
+            # client_event is like "notification", "request"
+            for client_event, handler_mark in HANDLER_MARKS.items():
+                event_registrator = getattr(api, "on_" + client_event, None)
+                if callable(event_registrator):
+                    server_events = getattr(func, handler_mark, [])  # type: List[str]
+                    for server_event in server_events:
+                        event_registrator(server_event, func)