https://getcomposer.org/

Composer - Dependency Management for PHP - helps you declare, manage and install dependencies of PHP projects.

Installation

homebrew

Install brew/update brew

brew update
brew tap homebrew/dupes
brew tap homebrew/php

Install the desired php version in terminal

brew install php56

Install composer

brew install composer

Commands

how to use composer

• https://getcomposer.org/doc/01-basic-usage.md
• https://getcomposer.org/doc/04-schema.md

Create basic composer.json file in current directory

composer init

this would guide you through creating composer.json

"require": {
	"monolog/monolog": "1.0.*"
  } 

Install the dependencies by running composer’s install command

'composer install —no-dev'  # install dependencies from "require" but not from "require-dev"
'composer install'          # will install from both

This would create:

• a vendor directory in your project with the required libraries and an auto loader used to load them into the project.

• a composer.lock file

• a autoload.php file within the /vendor directory

Info

Update command will fetch the latest matching versions (according to your composer.json file) and also update the lock file with the new version

Install command checks if a lock file is present, and if there is, it downloads the versions specified there (regardless of what composer.json says) Otherwise, composer will read the dependencies and versions from composer.json and create a lock file

Require composers auto loader in to your PHP script with

require '/path/to/vendor/autoload.php';

Optional - Updating packages

composer update —no-dev   # update dependencies from "require" but not from "require-dev"
composer update           # will update from both

update v install commands

composer update will update dependencies specified in composer.json

composer install will install dependencies specified in composer.lock

composer update will:

• Read composer.json
• Remove installed packages that are no more required in composer.json
• Check the availability of the latest versions of your required packages
• Install the latest versions of your packages
• Update composer.lock to store the installed packages version

composer install:

• Read composer.lock file
• Install the packages specified in the composer.lock file

composer.json schema

https://getcomposer.org/doc/04-schema.md#autoload

‘require’	Lists packages required by this package
‘require-dev’	Lists packages required for developing this package, or running tests, etc. Both install or update support the —no-dev option that prevents dev dependencies from being installed.
‘repositories’	By default Composer just uses the packagist repository. By specifying repositories you can get packages from elsewhere.
‘autoload’	Autoload mapping for a PHP autoloader. PSR-4 and PSR-0 autoloading, classmap generation and files includes are supported. ‘PSR-4’ /vendor/composer/autoload_psr4.php ‘PSR-0’ /vendor/composer/autoload_namespaces.php ‘classmap’ /vendor/composer/autoload_classmap.php You can use the classmap generation support to define autoloading for all libraries that do not follow PSR-0/4. To configure this you specify all directories or files to search for classes. ‘files’ Use if you want to require certain files explicitly on every request This is useful if your package includes PHP functions that are not in a class