added zustand and react query

Writerside/r.tree

@@ -69,11 +69,17 @@
     <toc-element topic="12-React-Folder-Structure.md"/>
     <toc-element topic="12-Advanced-State-Management-with-Redux-Toolkit.md">
         <toc-element topic="Setting-Up-Redux-Toolkit.md"/>
-        <toc-element topic="Handling-Asynchronous-Actions.md"/>
-        <toc-element topic="End2End-React-ReduxThunk-ExpressMongoDb-Posts-CRUD-APP.md"/>
+        <toc-element topic="Handling-Asynchronous-Actions.md">
+            <toc-element topic="1End2End-React-ReduxThunk-ExpressMongoDb-Posts-CRUD-APP.md"/>
+        </toc-element>
         <toc-element topic="RTK-Query-for-Data-Fetching.md">
             <toc-element topic="RTK-Query-Vs-Redux-Thunk.md"/>
             <toc-element topic="End2End-React-RTK-Query-ExpressMongoDb-Posts-CRUD-APP.md"/>
         </toc-element>
     </toc-element>
+    <toc-element topic="Advanced-State-Management-with-Zustand.md">
+        <toc-element topic="15-1-Counter-Example.md"/>
+        <toc-element topic="End2End-React-Zustand-ExpressMongoDb-Posts-CRUD-APP.md"/>
+        <toc-element topic="15-3-End2End-React-Zustand-ReactQuery-ExpressMongoDb-Posts-CRUD-APP.md"/>
+    </toc-element>
 </instance-profile>

Writerside/redirection-rules.xml

@@ -263,4 +263,12 @@
         </description>
         <accepts>11-Best-Practices-and-Common-Pitfalls.html</accepts>
     </rule>
+    <rule id="44c49b77">
+        <description>Created after removal of "Thunk ExpressMongoDb Posts CRUD APP" from React-TypeScript</description>
+        <accepts>End2End-React-ReduxThunk-ExpressMongoDb-Posts-CRUD-APP.html</accepts>
+    </rule>
+    <rule id="5fe8442d">
+        <description>Created after removal of "15.2 TodoApp Example" from React-TypeScript</description>
+        <accepts>TodoApp-Example.html</accepts>
+    </rule>
 </rules>

Writerside/topics/15-1-Counter-Example.md

@@ -0,0 +1,119 @@
+# 15.1 Counter Example
+
+Sure! Let's update your counter example to use the latest version of Zustand. As of now, the latest stable version is 4.5.5¹.
+
+### 1. Counter Example with Zustand and TypeScript
+
+First, let's build a simple counter app using Zustand, which will allow you to increment, decrement, and reset the counter.
+
+#### Step 1: Create a Counter Store with Zustand
+
+**File: `src/store/useCounterStore.ts`**
+
+```typescript
+import { create } from 'zustand';
+
+// Define the counter store state interface
+interface CounterState {
+  count: number;
+  increment: () => void;
+  decrement: () => void;
+  reset: () => void;
+}
+
+// Zustand store for managing the counter
+export const useCounterStore = create<CounterState>((set) => ({
+  count: 0,
+  increment: () => set((state) => ({ count: state.count + 1 })),
+  decrement: () => set((state) => ({ count: state.count - 1 })),
+  reset: () => set({ count: 0 }),
+}));
+```
+
+**Explanation:**
+
+- The Zustand store has three methods (`increment`, `decrement`, `reset`) and a `count` state.
+- The `set` function modifies the store’s state.
+
+#### Step 2: Create the Counter Component
+
+**File: `src/components/Counter.tsx`**
+
+```typescript
+import React from 'react';
+import { useCounterStore } from '../store/useCounterStore';
+
+const Counter: React.FC = () => {
+  const count = useCounterStore((state) => state.count);
+  const increment = useCounterStore((state) => state.increment);
+  const decrement = useCounterStore((state) => state.decrement);
+  const reset = useCounterStore((state) => state.reset);
+
+  return (
+    <div className="flex flex-col items-center space-y-4">
+      <h1 className="text-2xl font-bold">Counter: {count}</h1>
+      <div className="space-x-4">
+        <button
+          onClick={increment}
+          className="bg-blue-500 text-white px-4 py-2 rounded hover:bg-blue-600"
+        >
+          Increment
+        </button>
+        <button
+          onClick={decrement}
+          className="bg-red-500 text-white px-4 py-2 rounded hover:bg-red-600"
+        >
+          Decrement
+        </button>
+        <button
+          onClick={reset}
+          className="bg-gray-500 text-white px-4 py-2 rounded hover:bg-gray-600"
+        >
+          Reset
+        </button>
+      </div>
+    </div>
+  );
+};
+
+export default Counter;
+```
+
+**Explanation:**
+
+- We use `useCounterStore` to access the `count`, `increment`, `decrement`, and `reset` methods.
+- The component renders buttons to interact with the counter.
+
+#### Step 3: Bring It Together in App Component
+
+**File: `src/App.tsx`**
+
+```typescript
+import React from 'react';
+import Counter from './components/Counter';
+
+const App: React.FC = () => {
+  return (
+    <div className="container mx-auto p-4">
+      <h1 className="text-3xl font-bold text-center mb-6">Zustand Counter App</h1>
+      <Counter />
+    </div>
+  );
+};
+
+export default App;
+```
+
+#### Step 4: Run the App
+
+Start your app by running:
+
+```bash
+npm run dev
+```
+
+
+### Summary:
+- The **counter** example helped introduce Zustand's basic store management and state update.
+
+Feel free to ask any questions or

Writerside/topics/15-3-End2End-React-Zustand-ReactQuery-ExpressMongoDb-Posts-CRUD-APP.md

@@ -0,0 +1,188 @@
+# 15.3 End2End: React Zustand ReactQuery ExpressMongoDb Posts CRUD APP
+
+
+Combining Zustand with React Query can give you powerful state management and data fetching capabilities. Here's how you can integrate them:
+
+### Step 1: Install Dependencies
+
+First, make sure you have the necessary packages installed:
+
+```bash
+npm install zustand @tanstack/react-query axios
+```
+
+### Step 2: Create a Zustand Store
+
+We'll create a Zustand store to manage the state of our posts.
+
+**File: `src/store/usePostStore.ts`**
+
+```typescript
+import { create } from 'zustand';
+import { devtools } from 'zustand/middleware';
+import axios from 'axios';
+
+// Define the Post interface
+export interface Post {
+  _id: string;
+  title: string;
+  body: string;
+}
+
+// Define the state interface for the Zustand store
+interface PostState {
+  posts: Post[];
+  setPosts: (posts: Post[]) => void;
+}
+
+// Create the Zustand store with devtools middleware for debugging
+export const usePostStore = create<PostState>()(
+  devtools((set) => ({
+    posts: [], // Initial state for posts
+    setPosts: (posts) => set({ posts }), // Function to update posts in the state
+  }))
+);
+
+```
+
+### Step 3: Set Up React Query
+
+Next, we'll set up React Query to handle data fetching.
+
+**File: `src/hooks/usePosts.ts`**
+
+```typescript
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import axios from 'axios';
+import { usePostStore } from '../store/usePostStore';
+
+// Function to fetch posts from the API
+const fetchPosts = async () => {
+  const response = await axios.get('http://localhost:5000/api/posts');
+  return response.data;
+};
+
+// Custom hook to manage posts using React Query and Zustand
+export const usePosts = () => {
+  const setPosts = usePostStore((state) => state.setPosts);
+  const queryClient = useQueryClient();
+
+  // Fetch posts and update Zustand store on success
+  const { data, error, isLoading } = useQuery(['posts'], fetchPosts, {
+    onSuccess: (data) => {
+      setPosts(data);
+    },
+  });
+
+  // Mutation to create a new post
+  const createPost = useMutation(
+    (newPost) => axios.post('http://localhost:5000/api/posts', newPost),
+    {
+      onSuccess: () => {
+        queryClient.invalidateQueries(['posts']); // Invalidate queries to refetch posts
+      },
+    }
+  );
+
+  // Mutation to update an existing post
+  const updatePost = useMutation(
+    ({ id, updatedPost }) =>
+      axios.put(`http://localhost:5000/api/posts/${id}`, updatedPost),
+    {
+      onSuccess: () => {
+        queryClient.invalidateQueries(['posts']); // Invalidate queries to refetch posts
+      },
+    }
+  );
+
+  // Mutation to delete a post
+  const deletePost = useMutation(
+    (id) => axios.delete(`http://localhost:5000/api/posts/${id}`),
+    {
+      onSuccess: () => {
+        queryClient.invalidateQueries(['posts']); // Invalidate queries to refetch posts
+      },
+    }
+  );
+
+  return { data, error, isLoading, createPost, updatePost, deletePost };
+};
+
+```
+
+### Step 4: Create the Component
+
+Now, let's create a component to display and manage posts.
+
+**File: `src/components/PostList.tsx`**
+
+```typescript
+import React from 'react';
+import { usePosts } from '../hooks/usePosts';
+import { usePostStore } from '../store/usePostStore';
+
+const PostList: React.FC = () => {
+  const { data: posts, error, isLoading, createPost, updatePost, deletePost } = usePosts();
+  const postStore = usePostStore();
+
+  if (isLoading) return <div>Loading...</div>; // Display loading state
+  if (error) return <div>Error: {error.message}</div>; // Display error state
+
+  return (
+    <div>
+      <h1>Posts</h1>
+      <ul>
+        {postStore.posts.map((post) => (
+          <li key={post._id}>
+            <h2>{post.title}</h2>
+            <p>{post.body}</p>
+            <button onClick={() => deletePost.mutate(post._id)}>Delete</button>
+            <button onClick={() => updatePost.mutate({ id: post._id, updatedPost: { title: 'Updated Title', body: 'Updated Body' } })}>
+              Update
+            </button>
+          </li>
+        ))}
+      </ul>
+      <button onClick={() => createPost.mutate({ title: 'New Post', body: 'New Body' })}>Add Post</button>
+    </div>
+  );
+};
+
+export default PostList;
+
+```
+
+### Step 5: Integrate in App Component
+
+Finally, integrate everything in your main app component.
+
+**File: `src/App.tsx`**
+
+```typescript
+import React from 'react';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import PostList from './components/PostList';
+
+// Create a QueryClient instance
+const queryClient = new QueryClient();
+
+const App: React.FC = () => {
+  return (
+    <QueryClientProvider client={queryClient}>
+      <div className="container mx-auto p-4">
+        <h1 className="text-3xl font-bold text-center mb-6">Zustand and React Query App</h1>
+        <PostList />
+      </div>
+    </QueryClientProvider>
+  );
+};
+
+export default App;
+
+```
+
+### Explanation:
+
+- **Zustand Store**: Manages the local state of posts.
+- **React Query**: Handles data fetching, caching, and synchronization.
+- **PostList Component**: Displays posts and provides CRUD operations.

Writerside/topics/End2End-React-ReduxThunk-ExpressMongoDb-Posts-CRUD-APP.md → Writerside/topics/1End2End-React-ReduxThunk-ExpressMongoDb-Posts-CRUD-APP.md

@@ -1,5 +1,6 @@
 # End2End: React ReduxThunk ExpressMongoDb Posts CRUD APP
 
+
 This is a **fully functional CRUD app** using **TypeScript** for both the **Express backend** and the **React frontend**. The backend will use **MongoDB** for storing posts, and the frontend will use **Redux Toolkit(Thunk) ** to interact with the API for managing CRUD operations.
 
 ### **Step 1: Setting Up the Backend with Express, MongoDB, and TypeScript**
@@ -401,7 +402,7 @@ export default postSlice.reducer;
 ```
 
 3. **Store Configuration**:
-   - Path: `src/store/store.ts`
+    - Path: `src/store/store.ts`
 
    ```javascript
    import { configureStore } from '@reduxjs/toolkit';
@@ -460,8 +461,8 @@ export default postSlice.reducer;
    ```
 
 3. **Post Form Component**:
-   - path `src/components/PostForm.tsx`
-   
+    - path `src/components/PostForm.tsx`
+
 ```javascript
 import React, { useState } from 'react';
 import { useDispatch } from 'react-redux';