Micro-app frontend architecture (experimental) examples and templates of various approaches

At this moment, this example consists of a few Angular projects demonstrating an implementation of a main application called Envelope and micro applications that can be attached not only at the build time (micro application as a feature library), but above all, dynamically at runtime (from external sources eg. CDN, dedicated gateway).

The business case used as an example here is Administration Panel for an E-commerce system.

Example consists of following projects:

• Envelope /micro-frontend-envelope: Starting application with layout and main navigation that aggregates other apps. That's entry layer for every nested content in panel (read more),
• Orders /micro-frontend-app-orders: Demo micro application which acts as Orders section
  • Micro-app model where bundles can be hosted separately and referenced at runtime in Envelope app (read more),
• (more coming soon)

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Assumptions

• No coupling with external frameworks and libraries dedicated to micro-frontend architecture,
• The quality of the micro application code shouldn't be drastically reduced due to the adaptation to the technology used to attach micro applications to the envelope application.
• Micro applications can't be (very) toughly coupled to the technologies used only for attaching them to envelope. They should be easy to rewrite to a traditional model in case of problems with architecture. Developing such apps shouldn't be a one-way ticket.

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Potential use cases / Pros / Cons

• Multi-domain, big projects, especially if multiple teams are working on separate, complicated domains or are skilled in different technologies (Angular / React / Vue.js),
• Frequently changing website content, driven by A/B tests or AI decisions, when replacement at runtime has more pros compared to building dedicated release bundles and lets deliver features faster
• Web content management systems (CMSs/WCMSs)

Pros and cons differs depending on which exact micro-frontend model is used. They are listed in concrete projects.

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All technologies and tools used across projects

• Newest Angular 8
  • Going beyond typical use cases of Angular Elements
  • Envelope and all micro applications compatible with Lazy Loading Feature Modules and Angular Routing & Navigation
  • Extended Angular CLI possibilities without ejecting thanks to ngx-build-plus
• Web Components

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Setup / Usage / How to

In every project:

npm install

Development of Envelope or any single micro application can be independent and easy as default:

npm run start

To run all together:

1. Build and host bundles of every micro app that you want to test:

   npm run build
   npm run server
   

2. Serve or build Envelope application:

   For development and live-reload:

   npm run start
   

   Production:

   npm run bundle
   npm run server