How to composer autoload within a drupal 8 custom module

Question

How to autoload "non drupal" classes like Carbon when required via the modules own composer.json without altering drupals core composer.json (like using the composer-merge-plugin)? Where do I have to include composers autoload.php to use the third party libraries within MyModuleController?

My module structure (simplified)

src/
  MyModuleController.php
vendor/
  autoload.php
  ...
composer.json
composer.lock
my_module.info.yml
my_module.module

My module structure (simplified)

src/
  MyModuleController.php
vendor/
  autoload.php
  ...
composer.json
composer.lock
my_module.info.yml
my_module.module

user_722087 · Answer

You will have to include the path to the custom module in the repositories section of the composer.json in your root

"repositories": [
    {
        "type": "composer",
        "url": "https://packages.drupal.org/8"
    },
    {
        "type": "path",
        "url": "docroot/modules/custom/example"
    }
]

https://www.drupal.org/docs/develop/using-composer/managing-dependencies-for-a-custom-project

How to composer autoload within a drupal 8 custom module

1 Answers