feat: updated R session api

Author: ymarcon

datashield_opal/impl.py

@@ -50,6 +50,9 @@ def start(self, asynchronous: bool = True) -> None:
             raise OpalDSError(ValueError("Failed to start R session: no session id returned"))
         self.id = session["id"]
 
+    def is_started(self) -> bool:
+        return self.id is not None
+
     def is_ready(self) -> bool:
         if self.id is None:
             raise OpalDSError(ValueError("R session not started"))
@@ -77,7 +80,16 @@ def is_failed(self) -> bool:
         session = response.from_json()
         return session.get("state", "").lower() == "failed"
 
-    def get_state_message(self) -> str:
+    def is_terminated(self) -> bool:
+        if self.id is None:
+            raise OpalDSError(ValueError("R session not started"))
+        response = self._get(UriBuilder(["datashield", "session", self.id]).build()).send()
+        if response.code != 200:
+            raise OpalDSError(ValueError(f"Failed to check R session status: {response.code}"))
+        session = response.from_json()
+        return session.get("state", "").lower() == "terminated"
+
+    def get_last_message(self) -> str:
         if self.id is None:
             raise OpalDSError(ValueError("R session not started"))
         response = self._get(UriBuilder(["datashield", "session", self.id]).build()).send()