Added post and put and delete functionality both to user and modules, also updated users so that it by default has the user set to registered as not registered, but gives a dropdown allowing a person to select whether they are registered or not

src/components/screens/UserListScreen.js

@@ -1,9 +1,10 @@
-import {LogBox, Text} from "react-native";
+import {Alert, LogBox, Text} from "react-native";
 import Screen from "../layout/Screen";
 import UserList from "../entity/users/UserList";
 import {Button, ButtonTray} from "../UI/Button";
 import Icons from "../UI/Icons";
 import useLoad from "../API/useLoad";
+import API from "../API/API";
 
 const UserListScreen = ({navigation}) => {
     // Initialisation -------------
@@ -23,31 +24,31 @@ const UserListScreen = ({navigation}) => {
         navigation.goBack();
     };
 
-    const handleAdd = (user) => setUsers([...users, user]);
-
-    const handleModify = (updatedUser) => setUsers(
-        users.map((user) => (user.UserID === updatedUser.UserID) ? updatedUser : user),
-    );
-
-    const onAdd = (user) => {
-        handleAdd(user);
-        navigation.goBack();
+    const handleAdd = async (user) => {
+        const result = await API.post(usersEndpoint, user);
+        if (result.isSuccess) {
+            await loadUsers(usersEndpoint)
+            navigation.goBack();
+        } else
+            Alert.alert(result.message);
     };
 
-    const onModify = (user) => {
-        handleModify(user);
-        navigation.replace('UserViewScreen', {user, onDelete, onModify});
+    const onModify = async (user) => {
+        const putEndpoint = `${usersEndpoint}/${user.UserID}`;
+        const result = await API.put(putEndpoint, user);
+        if ( result.isSuccess ) {
+            await loadUsers(usersEndpoint)
+            navigation.navigate('UserListScreen');
+        } else
+            Alert.alert(result.message);
     };
 
     const goToViewScreen = (user) =>
         navigation.navigate('UserViewScreen', {user, onDelete, onModify});
 
     const goToAddScreen = () =>
-        navigation.navigate('UserAddScreen', {onAdd});
+        navigation.navigate('UserAddScreen', {onAdd: handleAdd});
 
-    const handleSwitchToModules = () => {
-        navigation.navigate("ModuleListScreen");
-    };
 
     // View -----------------------
     return (