Angular 8 + MongoDB example with Node.js Express: Build CRUD App

In this tutorial, I will show you how to make Angular 8 connect to MongoDB with Node.js Express. We’re gonna build a full-stack (MEAN stack) CRUD Application in which, the back-end server uses Node.js + Express for REST APIs, front-end side is an Angular App with HTTPClient.

Newer versions:
– Using Angular 10
– Using Angular 11
– Using Angular 12
– Using Angular 13
– Using Angular 14
– Using Angular 15

Related Posts:
– MEAN stack Authentication & Authorization with Angular 8 example
– Angular 8 upload file/image to Node.js Server example

Run both projects in one place:
How to Integrate Angular 8 with Node.js Restful Services

Angular + MongoDB example with Node.js Express

We will build a full-stack Tutorial Application in that:

• Tutorial has id, title, description, published status.
• User can create, retrieve, update, delete Tutorials.
• There is a search box for finding Tutorials by title.

Here are screenshots of the example.

– Add an object:

– Retrieve all objects:

– Click on Edit button to update an object:

On this Page, you can:

• change status to Published using Publish button
• delete the Tutorial using Delete button
• update the Tutorial details with Update button

– Search Tutorials by title:

Full-stack CRUD App Architecture

We’re gonna build the application with following architecture:

– Node.js Express exports REST APIs & interacts with MongoDB Database using Mongoose ODM.
– Angular Client sends HTTP Requests and retrieves HTTP Responses using HTTPClient, consume data on the components. Angular Router is used for navigating to pages.

Video

This is brief instruction on the Angular Node.js Express MongoDB application.

Node.js Express MongoDB Back-end

Overview

These are APIs that Node.js Express App will export:

Project Structure

– db.config.js exports configuring parameters for MongoDB connection & Mongoose.
– Express web server in server.js where we configure CORS, initialize & run Express REST APIs.
– Next, we add configuration for MongoDB database in models/index.js, create Mongoose data model in models/tutorial.model.js.
– Tutorial controller in controllers.
– Routes for handling all CRUD operations (including custom finder) in tutorial.routes.js.

Implementation

Create Node.js App

First, we create a folder:

$ mkdir nodejs-express-mongodb
$ cd nodejs-express-mongodb

Next, we initialize the Node.js App with a package.json file:

npm init

name: (nodejs-express-mongodb) 
version: (1.0.0) 
description: Node.js Restful CRUD API with Node.js, Express and MongoDB
entry point: (index.js) server.js
test command: 
git repository: 
keywords: nodejs, express, mongodb, rest, api
author: bezkoder
license: (ISC)

Is this ok? (yes) yes

We need to install necessary modules: express, mongoose and cors.
Run the command:

npm install express mongoose cors --save

Setup Express web server

In the root folder, let’s create a new server.js file:

const express = require("express");
const cors = require("cors");

const app = express();

var corsOptions = {
  origin: "http://localhost:8081"
};

app.use(cors(corsOptions));

// parse requests of content-type - application/json
app.use(express.json());

// parse requests of content-type - application/x-www-form-urlencoded
app.use(express.urlencoded({ extended: true }));

// simple route
app.get("/", (req, res) => {
  res.json({ message: "Welcome to bezkoder application." });
});

// set port, listen for requests
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}.`);
});

What we do are:
– import express and cors modules:

• Express is for building the Rest apis
• cors provides Express middleware to enable CORS with various options.

– create an Express app, then add body-parser (json and urlencoded) and cors middlewares using app.use() method. Notice that we set origin: http://localhost:8081.
– define a GET route which is simple for test.
– listen on port 8080 for incoming requests.

Now let’s run the app with command: node server.js.
Open your browser with url http://localhost:8080/, you will see:

Yeah, the first step is done. We’re gonna work with Mongoose in the next section.

Configure MongoDB database & Mongoose

In the app folder, we create a separate config folder for configuration with db.config.js file like this:

module.exports = {
  url: "mongodb://localhost:27017/bezkoder_db"
};

Define Mongoose

We’re gonna define Mongoose model (tutorial.model.js) also in app/models folder in the next step.

Now create app/models/index.js with the following code:

const dbConfig = require("../config/db.config.js");

const mongoose = require("mongoose");
mongoose.Promise = global.Promise;

const db = {};
db.mongoose = mongoose;
db.url = dbConfig.url;
db.tutorials = require("./tutorial.model.js")(mongoose);

module.exports = db;

Don’t forget to call connect() method in server.js:

...
const app = express();
app.use(...);

const db = require("./app/models");
db.mongoose
  .connect(db.url, {
    useNewUrlParser: true,
    useUnifiedTopology: true
  })
  .then(() => {
    console.log("Connected to the database!");
  })
  .catch(err => {
    console.log("Cannot connect to the database!", err);
    process.exit();
  });

Define the Mongoose Model

In models folder, create tutorial.model.js file like this:

module.exports = mongoose => {
  const Tutorial = mongoose.model(
    "tutorial",
    mongoose.Schema(
      {
        title: String,
        description: String,
        published: Boolean
      },
      { timestamps: true }
    )
  );

  return Tutorial;
};

This Mongoose Model represents tutorials collection in MongoDB database. These fields will be generated automatically for each Tutorial document: _id, title, description, published, createdAt, updatedAt, __v.

{
  "_id": "5e363b135036a835ac1a7da8",
  "title": "Js Tut#",
  "description": "Description for Tut#",
  "published": true,
  "createdAt": "2020-02-02T02:59:31.198Z",
  "updatedAt": "2020-02-02T02:59:31.198Z",
  "__v": 0
}

If you use this app with a front-end that needs id field instead of _id, you have to override toJSON method that map default object to a custom object. So the Mongoose model could be modified as following code:

module.exports = mongoose => {
  var schema = mongoose.Schema(
    {
      title: String,
      description: String,
      published: Boolean
    },
    { timestamps: true }
  );

  schema.method("toJSON", function() {
    const { __v, _id, ...object } = this.toObject();
    object.id = _id;
    return object;
  });

  const Tutorial = mongoose.model("tutorial", schema);
  return Tutorial;
};

And the result will look like this-

{
  "title": "Js Tut#",
  "description": "Description for Tut#",
  "published": true,
  "createdAt": "2020-02-02T02:59:31.198Z",
  "updatedAt": "2020-02-02T02:59:31.198Z",
  "id": "5e363b135036a835ac1a7da8"
}

After finishing the steps above, we don’t need to write CRUD functions, Mongoose Model supports all of them:

• create a new Tutorial: object.save()
• find a Tutorial by id: findById(id)
• retrieve all Tutorials: find()
• update a Tutorial by id: findByIdAndUpdate(id, data)
• remove a Tutorial: findByIdAndRemove(id)
• remove all Tutorials: deleteMany()
• find all Tutorials by title: find({ title: { $regex: new RegExp(title), $options: “i” } })

These functions will be used in our Controller.

Create the Controller

Inside app/controllers folder, let’s create tutorial.controller.js with these CRUD functions:

• create
• findAll
• findOne
• update
• delete
• deleteAll
• findAllPublished

const db = require("../models");
const Tutorial = db.tutorials;

// Create and Save a new Tutorial
exports.create = (req, res) => {
  
};

// Retrieve all Tutorials from the database.
exports.findAll = (req, res) => {
  
};

// Find a single Tutorial with an id
exports.findOne = (req, res) => {
  
};

// Update a Tutorial by the id in the request
exports.update = (req, res) => {
  
};

// Delete a Tutorial with the specified id in the request
exports.delete = (req, res) => {
  
};

// Delete all Tutorials from the database.
exports.deleteAll = (req, res) => {
  
};

// Find all published Tutorials
exports.findAllPublished = (req, res) => {
  
};

You can continue with step by step to implement this Node.js Express App in the post:
Node.js, Express & MongoDb: Build a CRUD Rest Api example

Run the Node.js Express Server

Run our Node.js application with command: node server.js.

Angular 8 Front-end

Overview

– The App component is a container with router-outlet. It has navbar that links to routes paths via routerLink.

– TutorialsList component gets and displays Tutorials.
– Tutorial component has form for editing Tutorial’s details based on :id.
– AddTutorial component has form for submission new Tutorial.

– These Components call TutorialService methods which use Angular HTTPClient to make HTTP requests and receive responses.

Project Structure

– There are 3 components: tutorials-list, tutorial-details, add-tutorial.
– tutorial.service has methods for sending HTTP requests to the Apis.
– app-routing.module.ts defines routes for each component.
– app component contains router view and navigation bar.
– app.module.ts declares Angular components and import necessary modules.

Implementation

Setup Angular 8 Project

Let’s open cmd and use Angular CLI to create a new Angular Project as following command:

ng new Angular8ClientCrud
? Would you like to add Angular routing? Yes
? Which stylesheet format would you like to use? CSS

We also need to generate some Components and Services:

ng g s services/tutorial

ng g c components/add-tutorial
ng g c components/tutorial-details
ng g c components/tutorials-list

Now you can see that our project directory structure looks like this.

Set up App Module

Open app.module.ts and import FormsModule, HttpClientModule:

...
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';

@NgModule({
  declarations: [ ... ],
  imports: [
    ...
    FormsModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Define Routes for Angular AppRoutingModule

There are 3 main routes:
– /tutorials for tutorials-list component
– /tutorials/:id for tutorial-details component
– /add for add-tutorial component

app-routing.module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { TutorialsListComponent } from './components/tutorials-list/tutorials-list.component';
import { TutorialDetailsComponent } from './components/tutorial-details/tutorial-details.component';
import { AddTutorialComponent } from './components/add-tutorial/add-tutorial.component';

const routes: Routes = [
  { path: '', redirectTo: 'tutorials', pathMatch: 'full' },
  { path: 'tutorials', component: TutorialsListComponent },
  { path: 'tutorials/:id', component: TutorialDetailsComponent },
  { path: 'add', component: AddTutorialComponent }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

Add Navbar and Router View to Angular CRUD App

Let’s open src/app.component.html, this App component is the root container for our application, it will contain a nav element.

<div>
  <nav class="navbar navbar-expand navbar-dark bg-dark">
    <a href="#" class="navbar-brand">bezKoder</a>
    <div class="navbar-nav mr-auto">
      <li class="nav-item">
        <a routerLink="tutorials" class="nav-link">Tutorials</a>
      </li>
      <li class="nav-item">
        <a routerLink="add" class="nav-link">Add</a>
      </li>
    </div>
  </nav>

  <div class="container mt-3">
    <router-outlet></router-outlet>
  </div>
</div>

Create Data Service

This service will use Angular HTTPClient to send HTTP requests.
You can see that its functions includes CRUD operations and finder method.

services/tutorial.service.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

const baseUrl = 'http://localhost:8080/api/tutorials';

@Injectable({
  providedIn: 'root'
})
export class TutorialService {

  constructor(private http: HttpClient) { }

  getAll() {
    return this.http.get(baseUrl);
  }

  get(id) {
    return this.http.get(`${baseUrl}/${id}`);
  }

  create(data) {
    return this.http.post(baseUrl, data);
  }

  update(id, data) {
    return this.http.put(`${baseUrl}/${id}`, data);
  }

  delete(id) {
    return this.http.delete(`${baseUrl}/${id}`);
  }

  deleteAll() {
    return this.http.delete(baseUrl);
  }

  findByTitle(title) {
    return this.http.get(`${baseUrl}?title=${title}`);
  }
}

Create Angular Components

As you’ve known before, there are 3 components corresponding to 3 routes defined in AppRoutingModule.

• Add new Item Component
• List of items Component
• Item details Component

You can continue with step by step to implement this Angular App in the post:
Angular 8 CRUD Application example with Web API

Newer versions:
– Angular 10 CRUD example with Web API
– Angular 11 CRUD example with Web API
– Angular 12 CRUD example with Web API
– Angular 13 CRUD example with Web API
– Angular 14 CRUD example with Web API
– Angular 15 CRUD example with Web API

Run the Angular App

You can run this App with command: ng serve --port 8081.
If the process is successful, open Browser with Url: http://localhost:8081/ and check it.

Source Code

You can find Github source code for this tutorial at: Angular + Express Github

Conclusion

Now we have an overview of how to make Angular 8 connect to MongoDB with Node.js Express when building a full-stack CRUD App (MEAN stack).

We also take a look at client-server architecture for REST API using Express & Mongoose ODM, as well as Angular 8 project structure for building a front-end app to make HTTP requests and consume responses.

Next tutorials show you more details about how to implement the system:
– Back-end
– Front-end:

• Using Angular 8
• Using Angular 10
• Using Angular 11
• Using Angular 12
• Using Angular 13
• Using Angular 14
• Using Angular 15

You will want to know how to run both projects in one place:
How to Integrate Angular 8 with Node.js Restful Services

More Practice with Pagination:
Server side Pagination with Node.js and Angular

Or security: MEAN stack Login & Registration with Angular 8 example

Or File Upload:
Angular 8 upload file/image to Node.js Server example

Happy learning, see you again!