How do I install my own, custom module dependant on Composer?

Question

I've looked all over, but there seems to be no advice on this online.

I've recently updated a Drupal 8 site to Drupal 9. I wasn't using composer before, and so I've used composerize-drupal to make the site composer compatible.

I have my own custom module on the site, and I had to uninstall it to get the composerize-drupal and then the upgrade to work.

I'm now trying to reinstall it, but there is a complete lack of guidance on this coming up in google searches, and if I just upload it to the site as before, the site breaks.

Can anybody please help shed some light on how this can be done on a Compserized Drupal 9 site?

Answer 1

In composer.json you tell Composer in which directories it should put certain types of dependencies.

"installer-paths": {
    "web/core": ["type:drupal-core"],
    "web/libraries/{$name}": ["type:drupal-library"],
    "web/modules/contrib/{$name}": ["type:drupal-module"],
    "web/profiles/contrib/{$name}": ["type:drupal-profile"],
    "web/themes/contrib/{$name}": ["type:drupal-theme"],
    "drush/Commands/contrib/{$name}": ["type:drupal-drush"]
},

These directories are now managed by Composer. For example web/modules/contrib for type drupal-module dependencies. While at the same time everything put in web/modules/custom or any other custom location will be preserved.

Your repo in the end basically only contains the composer.json/lock files at the repo root and all custom code (custom themes, custom modules, custom scripts, custom patches etc.) and config YAML files in their desired directories.

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You should gamble around a bit with the official recommended-project template or the community drupal-project template. Learn to read the composer.json file. Run composer install, manually delete certain directories, composer install again and observe what happens.

Answer 2

composerize-drupal creates the following directories for Composer dependencies:

• [drupal-root]/modules/contrib
• [drupal-root]/themes/contrib
• [drupal-root]/profiles/contrib

By convention (or at least the convention I follow), custom stuff goes in a custom directory.

• [drupal-root]/modules/custom
• [drupal-root]/themes/custom
• [drupal-root]/profiles/custom