This repo consists of two parts:

• demo-library: Demonstrates a way how to write a (probably company internal) Angular library. For a way how to write a public library, please visit: https://github.com/dherges/ng-packagr
• example-consumer: A small demo of how to use the library

It is also important to understand how the demo-library is setup itself. It's basically a regular Angular application:

src/app
  libex (libex is the module name)
  ...
  app.component.ts
  app.module.ts
build.js

Only what's inside of libex will get published to npm. That makes app.module.ts just a playground for you to test out your library. It's ideal to develop against, as all the components from your library are imported directly and you can work with hot reload and don't have to publish to npm (or run npm link) each time you want to implement or test a feature.

The only difference between the app.module.ts in example-consumer/src/app and demo-library/src/app is that example-consumer actually gets the published library from npm. This just serves the purpose for everyone reading the tutorial to see how exactly to use the published library. Notice the modified tsconfig.json of the example-consumer! If you want to test auto-import in IDE, I suggest opening exmaple-consumer as a separate project, otherwise the IDE will import the TypeScript classes from the demo-library.

All the library-building and -publishing logic is in demo-library/build.js. It's a lot less complex than in other library-generators, since it just publishes TypeScript source files. However, this requires an extra step on the side of the consumer, which is to add node_modules/libex/index.ts as sources to the tsconfig.json. You can run the script with node build.js from the demo-library folder.

To build real world libraries, a bit more than the minimal example can be helpful.

Additionally to what's minimally required to build a library, I've added a way to "theme" your library. The implementation is done in an equivalent way to the theming of Angular's Material Design library.

The example-consumer and the demo-library are in one repository. This is commonly referred to as a "Monorepo". This is quite useful to speed up development, as you can simply run lerna bootstrap (once you've installed lerna: https://github.com/lerna/lerna), which will symlink everything. Then you'll have the demo library as a symlink in the node_modules of example-consumer. If you now update something in demo-library, the project auto-refreshes even when started from example-consumer.