Introduction to Composer

Introduction Chinese documentation

Composer is a PHP-dependent management tool. It allows you to state the code base on which your project depends, and it installs them for you in your project.

Rely on management

Composer is not a package manager. Y es, it involves "packages" and "libraries," but it is managed on a per-project basis and installed in a directory vendor such as vendor. B y default, it does not install anything globally. Therefore, this is just a dependency management.

This idea is not new, and Composer was strongly inspired by node's (npm) and ruby's 'bundler' . At that time, there were no similar tools under PHP.

Composer will solve the problem for you like this:

a) You have a project that relies on several libraries.

b) Some of these libraries depend on others.

c) You declare what you depend on.

d) Composer will find out which version of the package needs to be installed and install them (download them to your project).

Declare a dependency

Let's say you're creating a project and you need a library to do logging. Y ou decide to use the "monolog" . To add it to your project, all you need to do is create a composer.json that describes the project's dependencies.

{
    "require": {
        "monolog/monolog": "1.2.*"
    }
}

Let's just point out that our project monolog/monolog packages, 1.2

System requirements

Running Composer requires PHP 5.3.2 plus or more. Some sensitive PHP settings and compilation flags are also required, but warnings are thrown for any incompatible installers.

Instead of simply downloading zip files, you'll need git, svn, or hg, depending on the version management system you load the package with.

Composer is multi-platform, and we're trying to make it work just as well on Windows, Linux, and OSX platforms.

Installation - snix

Download Composer's executable

Local installation

To really get Composer, we need to do two things. Install Composer first (again, which means it will be downloaded to your project):

curl -sS https://getcomposer.org/installer | php

Note: If the above method fails for some reason, you can also download the installer through php

php -r "readfile('https://getcomposer.org/installer');" | php

This checks some PHP settings and composer.phar into your working directory. T his is Composer's binary. This is a PHAR package (archive of PHP), which is the archive format of PHP that helps users do something on the command line.

You can specify composer's installation directory (it can be an absolute or relative path) by using the option of \--install-dir

curl -sS https://getcomposer.org/installer | php -- --install-dir=bin

Global installation

You can put this file anywhere. I f you put it in the PATH directory, you can access it globally. In a Unix-like system, you can even use it without php

You can execute these commands to composer make global calls in your system:

curl -sS https://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer

Note: If the appeal command fails because of permission execution, try running mv using sudo.

Now you only need composer command to use composer without having to enter php composer.phar

Global installation (on OSX via homebrew)

Composer is part of the homebrew-php project.

brew update
brew tap josegonzalez/homebrew-php
brew tap homebrew/versions
brew install php55-intl
brew install josegonzalez/php/composer

Install - Windows

Use the installer

This is the easiest way to install Composer on your machine.

Download and run the composer-Setup.exe, which installs the latest version of Composer and sets the system's environment variables, so you can use the composer command directly in composer

Install manually

Set the system's environment PATH and run the installation command to download the composer.phar file:

C:Usersusername>cd C:bin
C:bin>php -r "readfile('https://getcomposer.org/installer');" | php

Note: If you receive a readfile error prompt, http link or turn .ini on the php php_openssl.dll.

Create composer.phar peer composer.bat

C:bin>echo @php "%~dp0composer.phar" %*>composer.bat

Close the current command-line window and open a new command-line window to test:

C:Usersusername>composer -V
Composer version 27d8904

Use Composer

Now we'll use Composer to install the dependencies of the project. If you don't have composer.json in the current directory, check out the basic usage section.

To resolve and download dependencies, execute install command:

php composer.phar install

If you have a global installation and do not have a phar file in the current directory, use the following command instead:

composer install

Continuing with the example above, the monolog will be vendor/monolog/monolog directory.

Autoload

In addition to the library download, Composer has an automatic loading file that loads all the class files in the library downloaded by Composer. With it, you only need to add the following line of code to your project's boot file:

require 'vendor/autoload.php';

Now we can use monolog! To learn more about Composer, check out the Basic Usage section.