Composer - Installation and how to use Composer in PHP project

PHP Composer is a dependency manager for PHP. It allows us to declare the dependencies our project needs and installs them all automatically. This makes it easy to keep our project up-to-date, as well as share dependencies with other projects.

Check If PHP has been Installed

php -v

Install Composer

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

Move file to somewhere in our PATH

mv composer.phar /usr/local/bin/composer

General Commands to work with Composer

Check the current version of Composer:

composer -v

Update the latest version of Composer:

composer -selfupdate

Clear the Cache memory of Composer (to force Composer to reload libraries in the Cache memory):

composer clearcache

Search for library packages:

composer search library_name

Use Composer in PHP Projects

Create the composer.json file

This file contains all the data for setting up Composer for the project. To create the composer.json file, use the bellow command to the terminal.

composer init

This command guides us to create our composer.json file. Share the proper answer & we can see the preview at the end.

Check our project folder & we can see the newly created composer.json file.

Include Libraries into the PHP Project with Composer

Method 1 : using composer require command

composer require vendor/package

Example

composer require phpro/grumphp

This command will trigger Composer to download the phpro/grumphp library. The phpro/grumphp library will be saved in the vendor directory in our project.

Also check the composer.json file. The following code will be added in the file.

"require": {
        "phpro/grumphp": "^1.6.0"
    }

Method 2 : Add required libraries in composer.json file & use composer update command

Edit the composer.json file by adding the included library into the require section.

"library-name":"^the-smallest-version"

Example

"require": {
        "phpro/grumphp": "^1.6.0",
    }

Then enter the composer update command to install the library. This command will automatically update the latest version of the libraries that are necessary for the PHP project.

To use the above library in our project, we have to include the vendor/autoload.php file in the index.php file in the PHP project.

include vendor/autoload.php

Remove a Library from the PHP Project

Method 1: Using the composer command

composer remove vendor/package

Method 2: Update the composer.json file

Just go to the composer.json file, navigate to the require section, delete the library we want to remove and then enter the composer update command.

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This article was published on April 3, 2022

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