Implemented component version of authentication guard.

sports-matcher/client/src/components/AuthenticationGuard.js

@@ -0,0 +1,30 @@
+import React from "react";
+import { Navigate } from "react-router-dom";
+import { globalContext } from "../context";
+import { apiClient } from "../utils/httpClients";
+
+export default class AuthenticationGuard extends React.Component {
+    constructor(props) {
+        super(props);
+    }
+
+    async componentDidMount() {
+        if (!this.context.user) {
+            let userDataResponse = await apiClient.get("/user/");
+            if (userDataResponse.status === 200) {
+                this.context.user = userDataResponse.data;
+            }
+        }
+    }
+
+    static contextType = globalContext;
+
+    render() {
+        if (!this.context.user) {
+            return (
+                <Navigate to="/signup" replace="true" />
+            );
+        }
+        return;
+    }
+}