[UI][Common] Add daemon version check

deluge/tests/test_client.py

@@ -8,7 +8,7 @@
 from twisted.internet import defer
 
 from deluge import error
-from deluge.common import AUTH_LEVEL_NORMAL, get_localhost_auth
+from deluge.common import AUTH_LEVEL_NORMAL, get_localhost_auth, get_version
 from deluge.core.authmanager import AUTH_LEVEL_ADMIN
 from deluge.ui.client import Client, DaemonSSLProxy, client
 
@@ -170,3 +170,23 @@ def on_failure(failure):
 
         d.addCallbacks(self.fail, on_failure)
         return d
+
+    @pytest_twisted.inlineCallbacks
+    def test_daemon_version(self):
+        username, password = get_localhost_auth()
+        yield client.connect(
+            'localhost', self.listen_port, username=username, password=password
+        )
+
+        assert client.daemon_version == get_version()
+
+    @pytest_twisted.inlineCallbacks
+    def test_is_daemon_compatible(self):
+        username, password = get_localhost_auth()
+        yield client.connect(
+            'localhost', self.listen_port, username=username, password=password
+        )
+
+        assert client.is_daemon_compatible(get_version())
+        assert not client.is_daemon_compatible(f'{get_version()}1')
+        assert client.is_daemon_compatible('0.1.0')

deluge/ui/client.py

@@ -15,7 +15,7 @@
 from twisted.internet.protocol import ClientFactory
 
 from deluge import error
-from deluge.common import get_localhost_auth, get_version
+from deluge.common import VersionSplit, get_localhost_auth, get_version
 from deluge.decorators import deprecated
 from deluge.transfer import DelugeTransferProtocol
 
@@ -227,6 +227,7 @@ def clientConnectionLost(self, connector, reason):  # NOQA: N802
         self.daemon.host = None
         self.daemon.port = None
         self.daemon.username = None
+        self.daemon.daemon_info = None
         self.daemon.connected = False
 
         if (
@@ -260,6 +261,7 @@ def __init__(self, event_handlers=None):
         self.host = None
         self.port = None
         self.username = None
+        self.daemon_info = None
         self.authentication_level = 0
 
         self.connected = False
@@ -741,6 +743,24 @@ def connection_info(self):
 
         return None
 
+    @property
+    def daemon_version(self) -> str:
+        """
+        Get the connected daemon version
+
+        Returns:
+            the daemon version
+        """
+        return self._daemon_proxy.daemon_info if self.connected() else ''
+
+    def is_daemon_compatible(self, version=get_version()) -> bool:
+        daemon_version = self.daemon_version
+
+        if not (daemon_version and version):
+            return False
+
+        return VersionSplit(daemon_version) >= VersionSplit(version)
+
     def register_event_handler(self, event, handler):
         """
         Registers a handler that will be called when an event is received from the daemon.