README

This is a [Git subtree] (https://github.com/git/git/blob/master/contrib/subtree/git-subtree.txt) split of [Drupal] (https://github.com/drupal/drupal) 8's core directory which can be used to build the directory structure for a Drupal site and has the following advantages over pulling in the entire upstream Drupal repository:

• All the components of the Drupal site including Drupal, contributed modules and themes, as well as external libraries can be pulled in via [Composer] (https://getcomposer.org)
• Drupal and any external libraries can be bootstrapped via Composer (i.e. without installing any modules for the external libraries)
• One has full control over index.php, .htaccess, robots.txt, etc. as those files will not be overridden by a Drupal core update

Usage

Add the following to your site's composer.json:

{
    "require": {
        "composer/installers": "^1.0.20",
        "drupal/drupal-core": "8.0.*"
    },
}

(This repository is available on [Packagist] (https://packagist.org/packages/drupal/core), therefore the URL of this repository does not need to be specified explicitly.)

Directory layout

This will download Drupal's core directory into the root of the repository. If a Drupal 8 modules ships with a composer.json file, it will be downloaded into the modules directory where Drupal expects it. This works analogously for themes or installation profiles. (That the packages do not get placed into the vendor directory is a feature of the composer/installers package, therefore it is required.)

If you want to place Drupal core or modules, themes or installation profiles into different directories you can provide an "installer-paths" configuration directive in the "extra" section of the composer.json. To place the entire Drupal site in a subdirectory of the repository named web, for example, use the following:

{
    "extra": {
        "installer-paths": {
            "web/core": ["type:drupal-core"],
            "web/modules": ["type:drupal-module"],
            "web/profiles": ["type:drupal-profile"],
            "web/themes": ["type:drupal-theme"]
        }
    }
}

Or to place modules into a contrib subdirectory within the modules directory use:

{
    "extra": {
        "installer-paths": {
            "modules/contrib": ["type:drupal-module"]
        }
    }
}

Site template

In order to actually install Drupal you need to copy some files from the upstream Drupal repository into your repository root. The index.php, sites/default/default.services.yml and sites/default/default.settings.php files are required to operate Drupal and the .htaccess or web.config and the robots.txt files are recommended to copy as well. Copy the rest of the files to your liking.

You can copy the files by cloning the upstream Drupal repository and copying them manually or by fetching them directly via the command line. For example:

# Copy index.php from the upstream Drupal repository
wget https://raw.githubusercontent.com/drupal/drupal/8.0.x/index.php

See my [Drupal Site Template] (https://github.com/tstoeckler/drupal-site-template) for an example directory layout with the files needed to install and run Drupal including a composer.json file as given above. The template also includes the index.php modification and the drushrc.php in the way detailed below. Note that this site template follows the best practice of having the Drupal root be in a subdirectory of the repository, which is called web in this particular case.

Drupal's autoloader

The upstream Drupal repository contains all Composer dependencies and the Composer autoloader in the core/vendor directory. One of the purposes of this repository, however, is to take control of the autoloader used for bootstrapping Drupal. If you have pulled in additional libraries in your composer.json you will not be able to autoload them using Drupal's hardcoded autoloader. To instead use the autoloader generated from your composer.json for Drupal requests simply change the following line in index.php:

$autoloader = require_once __DIR__ . '/core/vendor/autoload.php';

appropriately, for example into:

$autoloader = require_once __DIR__ . '/vendor/autoload.php';

Adapting install.php (or authorize.php or rebuild.php) works in the same way, although those are in located in the core directory [unfortunately] (https://www.drupal.org/node/2406681) and thus modifications to these files cannot be placed under version control.

Drush's Drupal autoloader

When bootstrapping a Drupal site [Drush] (https://github.com/drush-ops/drush) loads Drupal's autoloader and by default uses Drupal's shipped autoloader (core/vendor/autoload.php). This, too, defies the purpose of this repository and will lead to fatal errors in case you are using a local Drush version installed from the same composer.json as Drupal. To make Drush use the autoloader generated from your composer.json call drush_drupal_load_autoloader() with the $new_autoloader argument from the site's drushrc.php. For example:

// In drush/drushrc.php
$autoloader = require __DIR__ . '/../../vendor/autoload.php';
drush_drupal_load_autoloader(NULL, $autoloader);

About this repository

This repository contains the Drupal core subtree split explained above in the 8.0.x branch mirroring the upstream branch. The master branch contains this README.md, an empty composer.json which is required for this repository to work with [Packagist] (https://packagist.org) and the subtree-split bash script which is used for maintaining the subtree split (and a .gitignore file). The usage of this script is explained in detail below. The tags in this repository are subtree splits of the respective upstream tags.

Usage of ./subtree-split

Initializing the repository

# Clone the repository
git clone https://github.com/tstoeckler/drupal-core.git
cd drupal-core

# Initialize the upstream repository
./subtree-split init

Updating the respository

./subtree-split fetch

Publishing the split repository

# Publish the 8.0.x branch
./subtree-split push branch 8.0.x

# Publish the 8.0.0-beta2 tag
./subtree-split push tag 8.0.0-beta2

Configuration

To use different upstream and downstream repositories or a different directory, place a subtree-split.config file in the root of this repository, that looks like the following:

UPSTREAM_REPOSITORY=https://github.com/drupal/drupal
UPSTREAM_DIRECTORY=upstream
DOWNSTREAM_REPOSITORY=git@github.com:tstoeckler/drupal-core.git

By default the DOWNSTREAM_REPOSITORY variable is taken from the remote.origin.url Git configuration value so that it does not need to be changed when forking this repository.