Magento 2 - Sample Module - Demonstrating the minimal requirements for using composer to copy files to app/code
composer config repositories.mttjohnson-module-sample-minimal-copy git [email protected]:mttjohnson/magento2-sample-module-minimal-copy.git
composer require mttjohnson/module-sample-minimal-copy:dev-master
bin/magento module:enable Mttjohnson_SampleMinimalCopy --clear-static-content
bin/magento setup:upgrade
composer config repositories.mttjohnson-module-sample-minimal-copy git [email protected]:mttjohnson/magento2-sample-module-minimal-copy.git
This will use composer to register a new repository composer config repositories. Using the command line tool to register a new repository we have to specify a repository name repositories.mttjohnson-module-sample-minimal-copy so I chose to make it similar to the name of my composer package so it's easier to associate a repository with the package it's used for. The type of repository is git and then the repository location you have access to [email protected]:mttjohnson/magento2-sample-module-minimal-copy.git.
composer require mttjohnson/module-sample-minimal-copy:dev-master
Here we use composer to add a new requirement to the project composer require and specify the name of the package mttjohnson/module-sample-minimal-copy and then specify what version we want dev-master and we use the speical dev- prefix to specify a branch name of master.
The composer require command here does a clone of your git repo and places that clone in vendor/mttjohnson/module-sample-minimal-copy. Because the composer type is magento2-module in the composer.json file, it will run the composer customer installer that is implemented by magento-composer-installer. The extra/map section of the composer.json file provides a map of files in your composer package to where they should be copied into the magento installation directory. In this case because it's a magento2-module the installer will copy files from vendor/mttjohnson/module-sample-minimal-copy to app/code/Mttjohnson/SampleMinimalCopy. When it copies the files the git repository files .git in the vendor directory do not get copied over to the app/code location and the files that Magento runs against will no longer be a part of your local cloned repository. This copy operation breaks the connection of your running code to your repository, and isn't suited very well for contributing back to the repository the module came from.
bin/magento module:enable Mttjohnson_SampleMinimalCopy --clear-static-content
This will enable the module with Magento and confirm that Magento knows that the module exists and is able to use it.
bin/magento setup:upgrade
Required after enabling a module to make sure any setup scripts are executed for the module and that the module version gets registered in the database.
It appears that as of Oct 7th modules that are copied also need the registration.php file in the module for them to be usable by Magento. Prior to the Oct 7th builds in the develop branch the registration.php file was not necessary.