installers

A Multi-Framework Composer Library Installer

This is for PHP package authors to require in their composer.json. It will
install their package to the correct location based on the specified package
type.

The goal of Installers is to be a simple package type to install path map.
Users can also customize the install path per package and package authors can
modify the package name upon installing.

Installers isn't intended on replacing all custom installers. If your
package requires special installation handling then by all means, create a
custom installer to handle it.

Natively Supported Frameworks:

Most frameworks these days natively work with Composer and will be
installed to the default vendor directory. composer/installers
is not needed to install packages with these frameworks.

Alternative to custom installers with Composer 2.1+

As of Composer 2.1, the Composer\InstalledVersions class has a
getInstalledPackagesByType
method which can let you figure out at runtime which plugins/modules/extensions are installed.

It is highly recommended to use that instead of building new custom
installers if you are building a new application. This has the advantage of leaving
all vendor code in the vendor directory, and not requiring custom installer code.

Current Supported Package Types

Stable types are marked as bold, this means that installation paths
for those type will not be changed. Any adjustment for those types would
require creation of brand new type that will cover required changes.

Example composer.json File

This is an example for a CakePHP plugin. The only important parts to set in your
composer.json file are "type": "cakephp-plugin" which describes what your
package is and "require": { "composer/installers": "~1.0" } which tells composer
to load the custom installers.

This would install your package to the Plugin/Ftp/ folder of a CakePHP app
when a user runs php composer.phar install.

So submit your packages to packagist.org!

Custom Install Paths

If you are requiring a package which has one of the supported types you can
override the install path with the following extra in your composer.json:

You can determine a non-standard installation path for all packages of a
particular type with the type: prefix. The type must be one of types
listed on the supported list above.

You can also install all packages by a particular vendor to a custom
installation path by using the vendor: prefix. The path will still
only apply to packages by the vendor with a type in the supported list.

These would use your custom path for each of the matching packages. The
available variables to use in your paths are: {$name}, {$vendor}, {$type}.

Note: If multiple custom installer-paths match for the same package, the first
one which matches will be used.

Custom Install Names

If you're a package author and need your package to be named differently when
installed consider using the installer-name extra.

For example you have a package named shama/cakephp-ftp with the type
cakephp-plugin. Installing with composer/installers would install to the
path Plugin/CakephpFtp. Due to the strict naming conventions, you as a
package author actually need the package to be named and installed to
Plugin/Ftp. Using the following config within your package composer.json
will allow this:

Please note the name entered into installer-name will be the final and will
not be inflected.

Disabling installers

There may be time when you want to disable one or more installers from composer/installers.
For example, if you are managing a package or project that uses a framework specific installer that
conflicts with composer/installers but also have a dependency on a package that depends on composer/installers.

Installers can be disabled for your project by specifying the extra
installer-disable property. If set to true, "all", or "*" all installers
will be disabled.

Otherwise a single installer or an array of installers may be specified.

Note: Using a global disable value (true, "all", or "*") will take precedence over individual
installer names if used in an array. The example below will disable all installers.

Should we allow dynamic package types or paths? No

What are they? The ability for a package author to determine where a package
will be installed either through setting the path directly in their
composer.json or through a dynamic package type: "type": "framework-install-here".

It has been proposed many times. Even implemented once early on and then
removed. Installers won't do this because it would allow a single package
author to wipe out entire folders without the user's consent. That user would
then come here to yell at us.

Anyone still wanting this capability should consider requiring https://github.com/oomphinc/composer-installers-extender.