Add websocket handling for selected flights.

client/src/components/socketprovider/socketprovider.tsx

@@ -0,0 +1,36 @@
+import { ReactChild, createContext, useEffect, useState } from "react";
+
+import { WEBSOCKET_URL } from "../../api/backend";
+
+const socket = new WebSocket(WEBSOCKET_URL);
+
+export const SocketContext = createContext(socket);
+
+interface SocketProviderProps {
+  children: ReactChild;
+}
+
+export const SocketProvider = (props: SocketProviderProps) => {
+  const [ws, setWs] = useState<WebSocket>(socket);
+  useEffect(() => {
+    const onClose = () => {
+      setWs(new WebSocket(WEBSOCKET_URL));
+    };
+
+    const onError = (error: Event) => {
+      console.log(`Websocket error: ${error}`);
+    };
+
+    ws.addEventListener("close", onClose);
+    ws.addEventListener("error", onError);
+
+    return () => {
+      ws.removeEventListener("close", onClose);
+      ws.removeEventListener("error", onError);
+    };
+  });
+
+  return (
+    <SocketContext.Provider value={ws}>{props.children}</SocketContext.Provider>
+  );
+};