PHP is a general-purpose server-side scripting language primarily used in web development. Originally created by Rasmus Lerdorf in 1994, it is now by The PHP Development Team.
PHP originally stood for “Personal Home Page”, but now stands for “PHP: Hypertext Preprocessor”.
- Homepage: php.net
- Documentation: php.net/docs.php
- PHP: The Right Way: phptherightway.com
- Interactive PHP Tutorial: learn-php.org
Topics, Tools and Terms
PHP packages were traditionally installed via PEAR (PHP Extension and Application Repository), but more recently the standard package and dependency management tool is Composer.
Composer lets us run install commands to add packages to our system, for example
composer require phpunit would add the unit testing framework PHPUnit to our system.
For instructions on how to install Composer visit getcomposer.org.
Managing dependencies manually is time-consuming, fortunately Composer can automate this.
We can list our dependencies in a
composer.json file and run
composer install to bring these into our project.
composer.json file looks like this:
The “require” block tells Composer that the Twig templating package is required for production use and can install Twig with a version of 2.x.x (ie. up to, but not including, version 3).
The “require-dev” block tells Composer that PHPUnit is required in development, but not in production.
Dependencies can be added to
composer require author/package-name
Development dependencies can be added by
composer require author/package-name --dev
Dependencies can be updated to their latest maximum version by running
Composer will also generate a
composer.lock file on each
composer update and the initial
composer install. This is not meant to be edited directly, it tells Composer to use specific versions of packages - particularly useful when hyhou want your development dependencies to match what you will push to production.
There are a number of testing tools available for PHP. The most popular one is PHPUnit. PHPUnit follows the classic xUnit approach.
Behat is the most popular behaviour-driven development (BDD) testing framework.
Codeception is a framework combining BDD, unit testing, and integration testing, and is cross-compatible with PHPUnit.
In our guides we will be using PHPUnit as the default testing framework.
A typical directory structure for a PHP project consists of a
src directory that contains all source files and a
tests directory that includes all tests. For web applications the publically accessible files (eg.
index.php) would reside in a
public directory which would then be your webservers document root.
Another common convention is having a
bin directory that may contain executable files to start your application.
We provided a working example of a minimal project on Github.
Directory names are in lower case. Class and interface files should be in upper case and match the class or interface names. Configuration, routes, and publically accessible files should be in lower case.
For example the class
Vanilla should be contained in file
Vanilla.php, the publically accessible route to the application should be
Tests match their production code file names with a
Test suffix, e.g. tests for code in
src/Vanilla.php should be written in
The repository for the example applications is available at github.com/vanilla-project/php-package.
The main application consists of basically two files:
public/example.phpis the main executable that instantiates and runs:
src/Example/Greeting.phpcontains the main application.
Running the Tests
All tests can be run by executing
phpunit will automatically find all tests inside the
test directory and run them based on the configuration in the
The first test for the class
Greeting verifies that the return value of the
sayHello method contains the name of the person and also contains the initial greeting “Good”.
The second and third tests uses stubs to override the default behaviour of the
DateTime class injected into the class’ constructor so that we can test the expected return value depending on the time of day.
Running the Application
PHP has an in-built server for local development. To run this change into the directory
public and run
php -S localhost:8000
Then open your browser at
You should see the text “Good Morning Ada Lovelace” being printed (or similar depending on the time of day).
Publishing a PHP Package to Packagist
composer require author/package-name is run,
composer will retrieve the package data from Packagist.
To publish your own package to Packagist you should go to packagist.org/packages/submit and enter the URL of your Git repository, then click check.
Once the checking phase has passed you can click submit and your PHP package will be on Packagist.
You can then require your package in any PHP project by running:
composer require your-packagist-username/your-project-name
Configuring Packagist as a Service
When you update your git repository you will likely want your Packagist package to be updated also.
For GitHub you can do the following:
- Retrieve your API token from Packagist from the Settings on Packagist;
- Open the settings of your repository on GitHub;
- Select “Webhooks & Services”;
- Click on Add Service and choose Packagist;
- Input your password when prompted;
- Paste the Packagist API token into the field on GitHub
When these settings are saved, updates on GitHub will be detected by Packagist.
Packages can have versions. When releasing a change you may want this to be versioned so users of your package will not be hit by breaking changes. By tagging a release on Git you can have that tag appear alongside your package on Packagist / Composer.
git tag <version>
git tag 1.0.0
git push origin 1.0.0
Your package will now have a version, and a specific version can be required:
composer require your-packagist-username/your-project-name:1.0.0