🥅 Handle fetch error callbacks

components/AlertModal.tsx

@@ -0,0 +1,61 @@
+// components/AlertModal.tsx
+import { Button, Modal, StyleSheet, Text, View } from 'react-native';
+import React                                     from 'react';
+
+type AlertModalProps = {
+    visible: boolean;
+    message: string;
+    onClose: () => void;
+};
+
+const AlertModal = ({ visible, message, onClose }: AlertModalProps) => {
+    return (
+        <Modal
+            animationType="slide"
+            transparent={true}
+            visible={visible}
+            onRequestClose={onClose}
+        >
+            <View style={styles.centeredView}>
+                <View style={styles.modalView}>
+                    <Text style={styles.modalText}>{message}</Text>
+
+                    <Button
+                        title="Close"
+                        onPress={onClose}
+                    />
+                </View>
+            </View>
+        </Modal>
+    );
+};
+
+const styles = StyleSheet.create({
+    centeredView: {
+        flex: 1,
+        justifyContent: "center",
+        alignItems: "center",
+        marginTop: 16
+    },
+    modalView: {
+        margin: 16,
+        backgroundColor: "white",
+        borderRadius: 16,
+        padding: 32,
+        alignItems: "center",
+        shadowColor: "#000",
+        shadowOffset: {
+            width: 0,
+            height: 2
+        },
+        shadowOpacity: 0.25,
+        shadowRadius: 4,
+        elevation: 5
+    },
+    modalText: {
+        marginBottom: 16,
+        textAlign: "center"
+    }
+});
+
+export default AlertModal;

components/MoveListItem.tsx

@@ -20,10 +20,8 @@ const MoveListItem: React.FC<MoveListItemProps> = ({ move, onPress, style }) =>
 const styles = StyleSheet.create({
     listItem: {
         backgroundColor: '#DDD',
-        padding: 20,
-        marginVertical: 8,
-        marginHorizontal: 16,
-        borderRadius: 10,
+        padding: 8,
+        borderRadius: 8,
     },
     listItemText: {
         color: '#333',

redux/actions/moveActions.ts

@@ -1,71 +1,105 @@
 // redux/actions/moveAction.ts
-import { CREATE_MOVE, DELETE_MOVE, GET_MOVES, UPDATE_MOVE } from '../constants';
-import { Move }                                             from "../../entities/Move";
-import { Dispatch }                                         from "redux";
-import { API_BASE_URL }                                     from "../../config";
+import { CREATE_MOVE, DELETE, DELETE_MOVE, GET, GET_MOVES, MOVE_ERROR, POST, PUT, UPDATE_MOVE } from '../constants';
+import {
+    Move
+}                                                                                               from "../../entities/Move";
+import { Dispatch }                                                                             from "redux";
+import { API_BASE_URL }                                                                         from "../../config";
 
 
 export const createMove = (move: Move) => {
+    const verb = POST
     return async (dispatch: Dispatch) => {
         try {
             const response = await fetch(`${API_BASE_URL}/move`, {
-                method: 'POST',
+                method: verb,
                 headers: {
                     'Content-Type': 'application/json',
                 },
                 body: JSON.stringify(move),
             });
+
+            if (!response.ok) {
+                throw new Error(`Failed to ${verb}:  ${response.statusText}`);
+            }
+
             const data = await response.json();
             dispatch({ type: CREATE_MOVE, payload: data });
         }
         catch (error) {
             console.error(error);
+            // @ts-ignore
+            dispatch({ type: MOVE_ERROR, payload: error.message });
         }
     }
 }
 
 export const getMoves = () => {
+    const verb = GET
     return async (dispatch: Dispatch) => {
         try {
             const response = await fetch(`${API_BASE_URL}/move`);
+
+            if (!response.ok) {
+                throw new Error(`Failed to ${verb}:  ${response.statusText}`);
+            }
+
             const data = await response.json();
             dispatch({ type: GET_MOVES, payload: data });
         }
         catch (error) {
             console.error(error);
+            // @ts-ignore
+            dispatch({ type: MOVE_ERROR, payload: error.message });
         }
     }
 }
 
 export const updateMove = (id: string, move: Move) => {
+    const verb = PUT
     return async (dispatch: Dispatch) => {
         try {
             const response = await fetch(`${API_BASE_URL}/move/${id}`, {
-                method: 'PUT',
+                method: verb,
                 headers: {
                     'Content-Type': 'application/json',
                 },
                 body: JSON.stringify(move),
             });
+
+            if (!response.ok) {
+                throw new Error(`Failed to ${verb}:  ${response.statusText}`);
+            }
+
             const updatedMove = await response.json();
             dispatch({ type: UPDATE_MOVE, payload: updatedMove });
         }
         catch (error) {
             console.error(error);
+            // @ts-ignore
+            dispatch({ type: MOVE_ERROR, payload: error.message });
         }
     }
 }
 
 export const deleteMove = (id: string) => {
+    const verb = DELETE
     return async (dispatch: Dispatch) => {
         try {
-            await fetch(`${API_BASE_URL}/move/${id}`, {
-                method: 'DELETE',
+            const response = await fetch(`${API_BASE_URL}/move/${id}`, {
+                method: verb,
             });
+
+            if (!response.ok) {
+                throw new Error(`Failed to ${verb}:  ${response.statusText}`);
+            }
+
             dispatch({ type: DELETE_MOVE, payload: id });
         }
         catch (error) {
             console.error(error);
+            // @ts-ignore
+            dispatch({ type: MOVE_ERROR, payload: error.message });
         }
     }
 }

redux/constants.ts

@@ -1,6 +1,12 @@
 // redux/constants.ts
 
+export const GET = 'GET';
+export const PUT = 'PUT';
+export const POST = 'POST';
+export const DELETE = 'DELETE';
+
 export const GET_MOVES = 'GET_MOVES';
 export const CREATE_MOVE = 'CREATE_MOVE';
 export const UPDATE_MOVE = 'UPDATE_MOVE';
 export const DELETE_MOVE = 'DELETE_MOVE';
+export const MOVE_ERROR = 'MOVE_ERROR';

redux/reducers/moveReducer.ts

@@ -1,9 +1,10 @@
 // redux/reducers/moveReducer.ts
-import { CREATE_MOVE, DELETE_MOVE, GET_MOVES, UPDATE_MOVE } from '../constants';
-import { Move }                                             from "../../entities/Move";
+import { CREATE_MOVE, DELETE_MOVE, GET_MOVES, MOVE_ERROR, UPDATE_MOVE } from '../constants';
+import { Move }                                                         from "../../entities/Move";
 
 export type MoveState = {
     moves: Move[];
+    error: string | null;
 };
 
 type MoveAction = {
@@ -13,27 +14,37 @@ type MoveAction = {
 
 const initialState: MoveState = {
     moves: [],
+    error: null
 }
 
 export default function moveReducer(state = initialState, action: MoveAction): MoveState {
     switch (action.type) {
         case GET_MOVES:
             return {
-                ...state, moves: action.payload as Move[] || []
+                ...state, moves: action.payload as Move[] || [],
+                error: null,
             };
         case CREATE_MOVE:
             return {
-                ...state, moves: [...state.moves, action.payload as Move]
+                ...state, moves: [...state.moves, action.payload as Move],
+                error: null,
             };
         case UPDATE_MOVE:
             return {
                 ...state,
-                moves: state.moves.map(move => move.id === (action.payload as Move).id ? action.payload as Move : move)
+                moves: state.moves.map(move => move.id === (action.payload as Move).id ? action.payload as Move : move),
+                error: null,
             };
         case DELETE_MOVE:
             return {
                 ...state,
-                moves: state.moves.filter(move => move.id !== action.payload)
+                moves: state.moves.filter(move => move.id !== action.payload),
+                error: null,
+            };
+        case MOVE_ERROR:
+            return {
+                ...state,
+                error: action.payload as string
             };
         default:
             return state;

screens/moves/MoveFormScreen.tsx

@@ -4,9 +4,9 @@ import React, { useState }                     from 'react';
 import { Button, StyleSheet, Text, TextInput } from 'react-native';
 import { StackNavigationProp }                 from '@react-navigation/stack';
 import { RootStackParamList }                  from "../../navigation/navigationTypes";
-import { useDispatch }                         from 'react-redux';
+import { useDispatch, useSelector }            from 'react-redux';
 import { createMove, updateMove }              from '../../redux/actions/moveActions';
-import { AppDispatch }                         from "../../redux/store";
+import { AppDispatch, RootState }              from "../../redux/store";
 import { Move }                                from "../../entities/Move";
 import { RouteProp }                           from "@react-navigation/native";
 import { MOVE_FORM }                           from "../../navigation/constants";
@@ -16,6 +16,8 @@ import { MoveCategoryName }                    from "../../entities/MoveCategory
 import { TypeName }                            from "../../entities/TypeName";
 import MultiSelect                             from "react-native-multiple-select";
 import { KeyboardAwareScrollView }             from "react-native-keyboard-aware-scroll-view";
+import AlertModal                              from "../../components/AlertModal";
+import { MOVE_ERROR }                          from "../../redux/constants";
 
 type MoveFormScreenNavigationProp = StackNavigationProp<RootStackParamList, typeof MOVE_FORM>;
 type MoveFormScreenRouteProp = RouteProp<RootStackParamList, typeof MOVE_FORM>;
@@ -26,6 +28,7 @@ type Props = {
 };
 
 const MoveFormScreen = ({ navigation, route }: Props) => {
+    const error = useSelector((state: RootState) => state.move.error);
     const dispatch = useDispatch();
     const [move, setMove] = useState<Move>(route.params?.move || {
         id: null,
@@ -41,7 +44,6 @@ const MoveFormScreen = ({ navigation, route }: Props) => {
         schemaVersion: 2
     });
 
-
     const [selectedWeakAgainst, setSelectedWeakAgainst] = useState<string[]>(move.type.weakAgainst);
     const [selectedEffectiveAgainst, setSelectedEffectiveAgainst] = useState<string[]>(move.type.effectiveAgainst);
 
@@ -69,6 +71,11 @@ const MoveFormScreen = ({ navigation, route }: Props) => {
 
     return (
         <KeyboardAwareScrollView style={styles.container}>
+            <AlertModal
+                visible={!!error}
+                message={error || ''}
+                onClose={() => dispatch({ type: MOVE_ERROR, payload: null })}
+            />
             <Text style={styles.label}>Name: </Text>
             <TextInput
                 value={move.name}

screens/moves/MoveListScreen.tsx

@@ -11,6 +11,8 @@ import { AppDispatch }                        from "../../redux/store";
 import MoveListItem                           from "../../components/MoveListItem";
 import { MOVE_DETAIL, MOVE_FORM, MOVE_LIST }  from "../../navigation/constants";
 import { RouteProp, useFocusEffect }          from "@react-navigation/native";
+import AlertModal                             from "../../components/AlertModal";
+import { MOVE_ERROR }                         from "../../redux/constants";
 
 type MoveListScreenNavigationProp = StackNavigationProp<RootStackParamList, typeof MOVE_LIST>;
 type MoveListScreenRouteProp = RouteProp<RootStackParamList, typeof MOVE_LIST>;
@@ -24,6 +26,7 @@ type RootState = {
 };
 
 const MoveListScreen = ({ navigation }: Props) => {
+    const error = useSelector((state: RootState) => state.move.error);
     const dispatch: AppDispatch = useDispatch();
     const moves = useSelector((state: RootState) => state.move.moves);
 
@@ -37,29 +40,36 @@ const MoveListScreen = ({ navigation }: Props) => {
     );
 
     return (
-        <FlatList
-            data={moves}
-            ListHeaderComponent={
-                <Button title="Add Move" onPress={() => navigation.navigate(MOVE_FORM, { move: undefined })}/>
-            }
-            renderItem={({ item }) => (
-                <View style={styles.listItemContainer}>
-                    <MoveListItem
-                        move={item}
-                        style={styles.moveListItem}
-                        onPress={() => navigation.navigate(MOVE_DETAIL, { move: item })}
-                    />
-                    <Button title="X"
-                            color={styles.deleteButton.backgroundColor}
-                            onPress={() => {
-                                if (item.id) {
-                                    dispatch(deleteMove(item.id))
-                                }
-                            }}/>
-                </View>
-            )}
-            keyExtractor={(item) => item.name}
-        />
+        <>
+            <AlertModal
+                visible={!!error}
+                message={error || ''}
+                onClose={() => dispatch({ type: MOVE_ERROR, payload: null })}
+            />
+            <FlatList
+                data={moves}
+                ListHeaderComponent={
+                    <Button title="Add Move" onPress={() => navigation.navigate(MOVE_FORM, { move: undefined })}/>
+                }
+                renderItem={({ item }) => (
+                    <View style={styles.listItemContainer}>
+                        <MoveListItem
+                            move={item}
+                            style={styles.moveListItem}
+                            onPress={() => navigation.navigate(MOVE_DETAIL, { move: item })}
+                        />
+                        <Button title="X"
+                                color={styles.deleteButton.backgroundColor}
+                                onPress={() => {
+                                    if (item.id) {
+                                        dispatch(deleteMove(item.id))
+                                    }
+                                }}/>
+                    </View>
+                )}
+                keyExtractor={(item) => item.name}
+            />
+        </>
     );
 };
 
@@ -71,10 +81,12 @@ const styles = StyleSheet.create({
         flexDirection: 'row',
         justifyContent: 'space-between',
         alignItems: 'center',
+        marginHorizontal: 16,
+        marginTop: 8,
     },
     moveListItem: {
         flex: 1,
-        marginRight: 10
+        marginRight: 8
     }
 });