Upload 6.24

part6/query-anecdotes/src/App.js

@@ -2,9 +2,11 @@ import AnecdoteForm from "./components/AnecdoteForm";
 import Notification from "./components/Notification";
 import { useQuery, useQueryClient, useMutation } from "react-query";
 import { getAnecdotes, updateAnecdote } from "./components/requests";
+import { useNotificationDispatch } from "./reducers/notificationReducer";
 
 const App = () => {
   const queryClient = useQueryClient();
+  const dispatch = useNotificationDispatch();
 
   const mutation = useMutation(updateAnecdote, {
     onSuccess: (newAnecdote) => {
@@ -18,11 +20,18 @@ const App = () => {
     },
   });
 
-  const handleVote = (anecdote) => {
+  const handleVote = async (anecdote) => {
     mutation.mutate({
       ...anecdote,
       votes: anecdote.votes + 1,
     });
+    await dispatch({
+      type: "SET_NOTIFICATION",
+      data: `You voted '${anecdote.content}'`,
+    });
+    setTimeout(() => {
+      dispatch({ type: "CLEAR_NOTIFICATION" });
+    }, 5000);
   };
 
   const { data: anecdotes, status } = useQuery("anecdotes", getAnecdotes, {

part6/query-anecdotes/src/components/AnecdoteForm.js

@@ -1,19 +1,30 @@
 import { useQueryClient, useMutation } from "react-query";
 import { createAnecdote } from "./requests";
+import { useNotificationDispatch } from "../reducers/notificationReducer";
 
 const AnecdoteForm = () => {
   const queryClient = useQueryClient();
+  const dispatch = useNotificationDispatch();
 
   const mutation = useMutation(createAnecdote, {
     onSuccess: (newAnecdote) => {
       const anecdotes = queryClient.getQueryData("anecdotes");
       queryClient.setQueryData("anecdotes", [...anecdotes, newAnecdote]);
     },
+    onError: (err) => {
+      dispatch({
+        type: "SET_NOTIFICATION",
+        data: `An error occurred: ${err.response.data.error}`,
+      });
+      setTimeout(() => {
+        dispatch({ type: "CLEAR_NOTIFICATION" });
+      }, 5000);
+    },
   });
 
   const getId = () => (100000 * Math.random()).toFixed(0);
 
-  const onCreate = (event) => {
+  const onCreate = async (event) => {
     event.preventDefault();
     const content = event.target.anecdote.value;
     event.target.anecdote.value = "";
@@ -22,6 +33,13 @@ const AnecdoteForm = () => {
       id: getId(),
       votes: 0,
     });
+    await dispatch({
+      type: "SET_NOTIFICATION",
+      data: `You created '${content}'`,
+    });
+    setTimeout(() => {
+      dispatch({ type: "CLEAR_NOTIFICATION" });
+    }, 5000);
   };
 
   return (

part6/query-anecdotes/src/components/Notification.js

@@ -1,18 +1,20 @@
+import { useNotificationValue } from "../reducers/notificationReducer";
+
 const Notification = () => {
   const style = {
-    border: 'solid',
+    border: "solid",
     padding: 10,
     borderWidth: 1,
-    marginBottom: 5
+    marginBottom: 5,
+  };
+
+  const notification = useNotificationValue();
+
+  if (!notification) {
+    return null;
   }
 
-  if (true) return null
+  return <div style={style}>{notification}</div>;
+};
 
-  return (
-    <div style={style}>
-      
-    </div>
-  )
-}
-
-export default Notification
+export default Notification;

part6/query-anecdotes/src/index.js

@@ -1,13 +1,16 @@
 import React from "react";
 import ReactDOM from "react-dom/client";
 import { QueryClient, QueryClientProvider } from "react-query";
+import { NotificationProvider } from "./reducers/notificationReducer";
 
 import App from "./App";
 
 const queryClient = new QueryClient();
 
 ReactDOM.createRoot(document.getElementById("root")).render(
+  <NotificationProvider>
     <QueryClientProvider client={queryClient}>
       <App />
     </QueryClientProvider>
+  </NotificationProvider>
 );

part6/query-anecdotes/src/reducers/notificationReducer.js

@@ -0,0 +1,37 @@
+import { createContext, useReducer, useContext } from "react";
+
+const notificationReducer = (state, action) => {
+  switch (action.type) {
+    case "SET_NOTIFICATION":
+      return action.data;
+    case "CLEAR_NOTIFICATION":
+      return null;
+    default:
+      return state;
+  }
+};
+
+const NotificationContext = createContext();
+
+const NotificationProvider = ({ children }) => {
+  const [notification, dispatch] = useReducer(notificationReducer, " ");
+
+  return (
+    <NotificationContext.Provider value={{ notification, dispatch }}>
+      {children}
+    </NotificationContext.Provider>
+  );
+};
+
+const useNotificationValue = () => {
+  const notificationAndDispatch = useContext(NotificationContext);
+  return notificationAndDispatch.notification;
+};
+
+const useNotificationDispatch = () => {
+  const notificationAndDispatch = useContext(NotificationContext);
+  return notificationAndDispatch.dispatch;
+};
+
+export { NotificationProvider, useNotificationValue, useNotificationDispatch };
+export default NotificationContext;