Composer template for Drupal projects
, (*1)
This project template should provide a kickstart for managing your site
dependencies with Composer., (*2)
If you want to know how to use it as replacement for
Drush Make visit
the Documentation on drupal.org., (*3)
Usage
First you need to install composer., (*4)
  
  Note: The instructions below refer to the global composer installation.
  You might need to replace composer with php composer.phar (or similar) 
  for your setup., (*5)
After that you can create the project:, (*6)
composer create-project caxy/drupal-project:8.x-dev some-dir --stability dev --no-interaction
With composer require ... you can download new dependencies to your 
installation., (*7)
cd some-dir
composer require drupal/devel:~1.0
The composer create-project command passes ownership of all files to the 
project that is created. You should create a new git repository, and commit 
all files not excluded by the .gitignore file., (*8)
What does the template do?
When installing the given composer.json some tasks are taken care of:, (*9)
- Drupal will be installed in the 
docroot-directory. 
- Autoloader is implemented to use the generated composer autoloader in 
vendor/autoload.php,
instead of the one provided by Drupal (docroot/vendor/autoload.php). 
- Modules (packages of type 
drupal-module) will be placed in docroot/modules/contrib/
 
- Theme (packages of type 
drupal-theme) will be placed in docroot/themes/contrib/
 
- Profiles (packages of type 
drupal-profile) will be placed in docroot/profiles/contrib/
 
- Creates default writable versions of 
settings.php and services.yml. 
- Creates 
sites/default/files-directory. 
- Latest version of drush is installed locally for use at 
vendor/bin/drush. 
- Latest version of DrupalConsole is installed locally for use at 
vendor/bin/drupal. 
Updating Drupal Core
This project will attempt to keep all of your Drupal Core files up-to-date; the 
project drupal-composer/drupal-scaffold 
is used to ensure that your scaffold files are updated every time drupal/core is 
updated. If you customize any of the "scaffolding" files (commonly .htaccess), 
you may need to merge conflicts if any of your modfied files are updated in a 
new release of Drupal core., (*10)
Follow the steps below to update your core files., (*11)
- Run 
composer update drupal/core --with-dependencies to update Drupal Core and its dependencies. 
- Run 
git diff to determine if any of the scaffolding files have changed. 
Review the files for any changes and restore any customizations to 
.htaccess or robots.txt. 
- Commit everything all together in a single commit, so 
docroot will remain in
sync with the core when checking out branches or running git bisect. 
- In the event that there are non-trivial conflicts in step 2, you may wish 
to perform these steps on a branch, and use 
git merge to combine the 
updated core files with your customized files. This facilitates the use 
of a three-way merge tool such as kdiff3. This setup is not necessary if your changes are simple; 
keeping all of your modifications at the beginning or end of the file is a 
good strategy to keep merges easy. 
Generate composer.json from existing project
With using the "Composer Generate" drush extension
you can now generate a basic composer.json file from an existing project. Note
that the generated composer.json might differ from this project's file., (*12)
Creating a site profile
We advise that all projects be created as a Drupal 8 profile and that
Composer be used to manage Drupal dependencies within the profile., (*13)
mkdir docroot/profiles/specialproject
Create a composer.json file in the profile's directory, for example:, (*14)
{
    "name": "my-company/special-project-profile",
    "type": "drupal-profile",
    "repositories": [
        {
            "type": "composer",
            "url": "https://packagist.drupal-composer.org"
        }
    ],
    "require": {
        "drupal/metatag": "~8.0@dev"
    }
}
Add this to your root level composer.json:, (*15)
{
    "require": {
        "wikimedia/composer-merge-plugin": "^1.3.0"
    },
    "extra": {
        "merge-plugin": {
            "include": [
                "docroot/profiles/specialproject/composer.json"
            ]
        }
    }
}
This will allow you to maintain a composer.json file for your profile separate
from the Drupal composer platform's dependencies while keeping the simplicity of
running composer update from the root level to update dependencies for the
Drupal platform and the profile at the same time., (*16)
FAQ
Should I commit the contrib modules I download?
Composer recommends no. They provide argumentation against but also 
workrounds if a project decides to do it anyway., (*17)
Should I commit the scaffolding files?
The drupal-scaffold plugin can download the scaffold files (like
index.php, update.php, …) to the web/ directory of your project. If you have not customized those files you could choose
to not check them into your version control system (e.g. git). If that is the case for your project it might be
convenient to automatically run the drupal-scaffold plugin after every install or update of your project. You can
achieve that by registering @drupal-scaffold as post-install and post-update command in your composer.json:, (*18)
"scripts": {
    "drupal-scaffold": "DrupalComposer\\DrupalScaffold\\Plugin::scaffold",
    "post-install-cmd": [
        "@drupal-scaffold",
        "..."
    ],
    "post-update-cmd": [
        "@drupal-scaffold",
        "..."
    ]
},
How can I apply patches to downloaded modules?
If you need to apply patches (depending on the project being modified, a pull 
request is often a better solution), you can do so with the 
composer-patches plugin., (*19)
To add a patch to drupal module foobar insert the patches section in the extra 
section of composer.json:, (*20)
"extra": {
    "patches": {
        "drupal/foobar": {
            "Patch description": "URL to patch"
        }
    }
}
How do I use this on Acquia cloud?
Add this to your settings.php before deploying to Acquia Cloud. Replace AH_SITE_GROUP with the name of your site
group in Acquia Cloud., (*21)
<?php
// On Acquia Cloud, this include file configures Drupal to use the correct
// database in each site environment (Dev, Stage, or Prod). To use this
// settings.php for development on your local workstation, set $db_url
// (Drupal 5 or 6) or $databases (Drupal 7 or 8) as described in comments above.
if (file_exists('/var/www/site-php')) {
  // As of 29 October 2015, Acquia Cloud does not support release candidates of Drupal 8,
  // so we must define `conf_path` function which was removed between beta15 and RC1.
  if (!function_exists('conf_path')) {
    function conf_path() {
      $request = \Symfony\Component\HttpFoundation\Request::createFromGlobals();
      return \Drupal\Core\DrupalKernel::findSitePath($request, FALSE);
    }
  }
  require('/var/www/site-php/AH_SITE_GROUP/AH_SITE_GROUP-settings.inc');
}
The Acquia Connector should be added to the root level composer.json unless your site profile
can only run on the Acquia Cloud environment., (*22)
{
    "require": {
        "drupal/acquia_connector": "8.1.*@dev"
    }
}
You never need this module, and it probably will not work correctly as there is no longer
a composer.json file within the document root. It is incorrect for contrib modules to
declare this dependency explicitly, because it is never the only way to run a module
that has composer PHP dependencies., (*23)
In a module or your project profile, add this hook implementation:, (*24)
<?php
/**
 * Implements hook_system_info_alter().
 */
function MODULE_system_info_alter(array &$info, \Drupal\Core\Extension\Extension $file, $type) {
  // remove composer_manager dependency.
  if (isset($info['dependencies']) && !empty($info['dependencies'])) {
    $info['dependencies'] = array_diff($info['dependencies'], array('composer_manager'));
  }
}