Introduction

In this guide, you'll learn how to build a web application with MongoDB and the MEAN Stack. The MEAN Stack comprises four technologies: MongoDB (a NoSQL database), Express.js (a web application framework), Angular (a frontend framework), and Node.js (a server-side JavaScript runtime). We'll cover the basics of setting up your development environment, creating a full-stack web application, and using MongoDB to store and retrieve data. Sample code and examples will guide you through the process.

Prerequisites

Before you begin, make sure you have the following prerequisites:

• Node.js and npm (Node Package Manager) installed on your system.
• An integrated development environment (IDE) or a code editor for writing code.
• MongoDB installed and running locally or accessible through a connection string.
• Basic knowledge of JavaScript and web development concepts.

Step 1: Setting Up the Backend with Node.js and Express

Start by setting up the backend of your web application using Node.js and Express. You'll create RESTful API endpoints to handle data operations. Here's an example of how to create a simple API endpoint to retrieve data from MongoDB:

const express = require('express');
const app = express();
const mongoose = require('mongoose');
// Connect to MongoDB
mongoose.connect('mongodb://localhost/mydb', { useNewUrlParser: true, useUnifiedTopology: true });
// Define a data model (e.g., for "Task")
const Task = mongoose.model('Task', {
    title: String,
    description: String
});
// Define a route to fetch tasks
app.get('/api/tasks', async (req, res) => {
    const tasks = await Task.find();
    res.json(tasks);
});
// Start the Express app
app.listen(3000, () => {
    console.log('Server is running on port 3000');
});
        

Step 2: Creating the Angular Frontend

Next, create the frontend of your web application using Angular. You'll build components and templates to display data from the backend. Here's an example of an Angular component that fetches and displays tasks from the Express.js backend:

import { Component, OnInit } from '@angular/core';
import { HttpClient } from '@angular/common/http';
@Component({
  selector: 'app-task-list',
  templateUrl: './task-list.component.html',
  styleUrls: ['./task-list.component.css']
})
export class TaskListComponent implements OnInit {
  tasks: any[];
  constructor(private http: HttpClient) {}
  ngOnInit() {
    this.http.get('/api/tasks').subscribe((data: any) => {
      this.tasks = data;
    });
  }
}
        

Step 3: Building the MongoDB Data Model

Create a MongoDB data model using Mongoose to define the structure of your data. In the provided Express.js example, we used a simple "Task" model. Here's how to define it:

const mongoose = require('mongoose');
// Define a data model (e.g., for "Task")
const Task = mongoose.model('Task', {
    title: String,
    description: String
});
        

Step 4: Implementing CRUD Operations

You can now implement CRUD (Create, Read, Update, Delete) operations for your web application. Here's an example of creating a new task:

app.post('/api/tasks', async (req, res) => {
    const task = new Task(req.body);
    await task.save();
    res.json(task);
});
        

For the frontend, you can create forms and Angular components to allow users to interact with the data, such as creating, updating, and deleting tasks.

Conclusion

You've successfully built a web application with the MEAN Stack and MongoDB. This guide covers the basics of setting up your development environment, creating a full-stack web application, and using MongoDB to store and retrieve data. With these foundational skills, you can explore more advanced features, add authentication, and further customize your MEAN Stack application.