Micro frontends demo

For a lab version of the same project, see https://github.com/kito99/micro-frontends-lab.

This is a simple application that demonstrates one approach to creating Micro frontends: using Web Components to integrate different web apps. It was originally demoed at Oracle CodeOne 2019 in San Francisco as part of the talk Micro Front Ends: Breaking Up the Front-End Monolith (slides) (mind map) by Kito D. Mann (@kito99), Principal Consultant at virtua.tech.

There are several sub-projects in this repo:

• orchestrator - Entry point for the app; simple HTML page that uses the Vaadin Router web component to dynamically load different micro frontends.
• app-one - Simple web app that uses Web Components. Built with lit-element and lit-html, and uses the cute emoji slider web component.
• app-two - Default app created using the Angular 8 CLI, but packaged as a web component via Angular Elements.
• app-three - Another Angular 8 created via the CLI and packaged via Angular Elements, but this one uses the PrimeNG Table component to talk to the app-three-service microservice.
• app-three-service - Simple microservice built using Java and the MicroProfile standard running on Payara Micro; returns canned data.

NOTE: This project does not currently use any polyfills for Web Components or other standards, so evergreen browsers are required. (If you want polyfills, you'll need to add them from https://github.com/webcomponents/polyfills)

It's theoretically possible to include other technologies using this method, such as React via Adobe's react-webcomponent, or Vue.js via vue-web-component-wrapper.

Running

First, make sure you have Node (for JS/TS) and Maven (for Java) installed.

1. Download dependencies and build each app as described in the individual README located in the app's folder.
2. Run app-three-service as described in the project's README.
3. Run a web server from the root folder, and point it to orchestrator/index.html. For simplicity, the project includes express, which can be used to serve the app.

To setup express, install the dependencies:

 npm install 

Then run the server:

cd <root folder of this repo>
node server.js

And point your browser to the URL indicated (usually http://127.0.0.1:8000).

Technically, all of these apps could run on separate servers (using
CORS headers) or be proxied through the main web server.