creating a custom module in Drupal 8

another stub.

I needed a working example of a custom module, so this will be it.

why use custom modules? some Drupal customizations require writing functions that are included when Drupal 8 executes, such as rewriting the language menu in a "preprocess template function", and these must go into a custom module.

Most customized sites include a site-specific module.

*Drupal 8 edit: actually, the above changed with Drupal 8, where themes include a THEMENAME.theme file which contains theme-specific php code. so this in effect scraps the need for a custom module just for theming.

the following 2 pages helped me to build my first module - I feel these are better tutorials than those available at drupal.org:

https://suyati.com/blog/drupal-8-module-development/

https://www.kalose.net/oss/drupal-8-create-simple-module/