events: create an event to open a new tab in Jupyter Lab

cylc/uiserver/app.py

@@ -95,6 +95,7 @@
 from cylc.uiserver.handlers import (
     CylcStaticHandler,
     CylcVersionHandler,
+    CylcLabBridgeHandler,
     SubscriptionHandler,
     UIServerGraphQLHandler,
     UserProfileHandler,
@@ -491,6 +492,11 @@ def initialize_settings(self):
             self.scan_interval * 1000
         ).start()
 
+        # register Jupyter Event schemas
+        self.serverapp.event_logger.register_event_schema(
+            Path(__file__).parent / 'event_schemas/test.yml'
+        )
+
     def initialize_handlers(self):
         self.authobj = self.set_auth()
         self.set_sub_server()
@@ -501,6 +507,11 @@ def initialize_handlers(self):
                 CylcVersionHandler,
                 {'auth': self.authobj}
             ),
+            (
+                'cylc/lab-bridge/([^/]+)/(.*)',
+                CylcLabBridgeHandler,
+                {'auth': self.authobj}
+            ),
             (
                 'cylc/graphql',
                 UIServerGraphQLHandler,

cylc/uiserver/event_schemas/test.yml

@@ -0,0 +1,11 @@
+$id: http://events.cylc.org/test
+version: 1
+title: Test
+description: An interesting event to collect
+properties:
+  name:
+    title: Name of Event
+    type: string
+  path:
+    title: File to open
+    type: string

cylc/uiserver/handlers.py

@@ -18,6 +18,7 @@
 import json
 import getpass
 import os
+from pathlib import Path
 import re
 from typing import TYPE_CHECKING, Callable, Dict
 
@@ -206,6 +207,26 @@ def get(self, path):
         return web.StaticFileHandler.get(self, path)
 
 
+class CylcLabBridgeHandler(CylcAppHandler):
+
+    @authorised
+    @web.authenticated
+    def get(self, event, path):
+        from urllib.parse import unquote
+        path = Path(unquote(path))
+        if not path.is_absolute():
+            path = Path('~', path)
+        path.expanduser()
+        path = path.relative_to(Path('~').expanduser())
+
+        event = {'name': event, 'path': str(path)}
+        self.serverapp.event_logger.emit(
+            schema_id='http://events.cylc.org/test',
+            data=event,
+        )
+        self.write(f'<pre>{event}</pre>')
+
+
 class CylcVersionHandler(CylcAppHandler):
     """Renders information about the Cylc environment.