Fun with Micro-frontend in a single-spa way💡

🏃‍♂️
To give everyone the context this post will be based on the experiments which I used to run the multiple front-end applications under a vanilla js container app.

What is a Micro-frontend application?

This application is based on a single-spa framework that allows you to run multiple front-end applications under the same route. Things to notice related to the Micro-frontend app

Deploy the micro front-end applications independently.
Without re-writing the existing application, you can create a new application with the new framework.
Lazy loading the code base for improved performance.

Pre-requisites

Knowledge of any JavaScript framework
JavaScript
single-spa should be globally installed in your machine

Build the application

We will create three applications using the single-spa framework that are as follow:-

root-config
react-app
angular-app

We will render the react and angular apps based on the routes.
So if the route is

/react then react app will load
/angular then the angular app will load

Step 1:

Create a folder where you want to put all three applications together.
Navigate to the root of the folder and run the following command and follow the instructions as provided in the image:

$ npx create-single-spa

The root-config setup will complete in sometime.

Step 2:

Now we will create an react application using the single-spa. So in the same root folder run the following command and follow the instructions as provided in the image:

$ npx create-single-spa

Step 3:

Now we will create an angular application using the single-spa. So in the same root folder run the following command and follow the instructions as provided in the image:

$ npx create-single-spa

Few more agreements for the angular app 😀

You need to additionally install few dependencies for the angular project

$ npm i -D @angular-builders/custom-webpack single-spa

Step 4:

Now we will add few minor tweaks in the files present in our newly created projects :-

root-config

Update the imports in the index.ejs

 {
  "imports": {
    "@orgname/root-config": "//localhost:9000/orgname-root-config.js",
    "@orgname/react-app": "//localhost:8080/orgname-react-app.js",
    "angular-app": "//localhost:4200/main.js"
  }
}

Update the configuration file named as orgname-root-config.ts
Add the navigation bar in index.ejs inside the body

<style>
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  background-color: #111D4A;
  color: white;
  font-size: 18px;
  font-weight: bold;
  width: 100%;
  height: 75px;
  display: flex;
  align-items: center;
}

.navbar ul {
  display: flex;
  align-items: center;
  list-style-type: none;
  height: 100%;
}

.navbar li {
  padding-right: 24px;
  height: 100%;
}

.navbar li:hover {
  opacity: 0.8;
}

.navbar a {
  text-decoration: none;
  color: white;
}
</style>
<div class="navbar">
<ul>
  <a onclick="singleSpaNavigate('/react')">
    <li>
      React
    </li>
  </a>
  <a onclick="singleSpaNavigate('/angular')">
    <li>
      Angular
    </li>
  </a>
</ul>
</div>

react-app
- Update the root.component.tsx as below
angular-app
- Import the zonejs as a dependency in main.single-spa.ts
- Add { provide: APP_BASE_HREF, useValue: '/angular' } to the providers array in the app.module.ts and import APP_BASE_HREF from @angular/common module