To run custom logic, use Composer scripts, first add scripts blocks in composer.json and bind events. The main steps are: 1. Understand the built-in events of Composer such as pre-install-cmd, post-install-cmd, etc.; 2. Set scripts block, specify commands or script arrays as needed, and execute them in order; 3. Use class processing to achieve more complex control, and receive Event and IO interfaces through static methods; 4. Manually run Composer commands during testing and check the output and return code to ensure that the script works normally.

When you want to run custom logic during Composer operations—like installing, updating, or dumping autoloads—you can hook into Composer events using the scripts section in your composer.json . This lets you automate tasks like clearing caches, running build steps, or triggering notifications based on what Composer is doing.

Here's how to actually make use of Composer scripts and respond to its built-in events.

Understanding Composer Events and Script Names

Composer fires off a number of predefined events during its lifecycle. These include:

• pre-install-cmd
• post-install-cmd
• pre-update-cmd
• post-update-cmd
• pre-autoload-dump
• post-autoload-dump
• post-package-install
• post-package-update
• post-root-package-install

Each of these script names corresponds to an event that happens during a Composer command. For example, post-install-cmd runs after composer install , and post-update-cmd runs after composer update .

You don't have to use all of them, but knowing which ones exist helps you choose the right moment to inject your own logic.

Setting Up Scripts in composer.json

To hook into any of these events, just add a scripts block to your composer.json . Here's a basic example:

 {
  "scripts": {
    "post-install-cmd": [
      "echo 'Composer install complete!'",
      "php bin/notify_dev_team.php"
    ],
    "post-update-cmd": "php bin/clear_cache.php"
  }
}

In this case:

• After composer install , it prints a message and triggers a notification script.
• After composer update , it clears the cache by calling a PHP file.

You can also call shell scripts, artisan commands (in Laravel), or even npm scripts if needed. Just make sure the paths are correct and executable.

A few tips:

• You can list multiple commands per event as an array.
• Each command is executed in order.
• If one fails, Composer will stop unless you prepend @ to ignore failures: @php something-that-might-fail.php

Using Event Classes for More Control

If you need more flexibility or want to pass parameters from Composer to your code, you can use a class-based handler instead of just a shell command.

For example:

 {
  "scripts": {
    "post-install-cmd": "My\\Script\\Handler::onPostInstall"
  }
}

This assumes you've written a class My\Script\Handler with a static method onPostInstall() . The method receives two arguments:

• An instance of Composer\Script\Event
• The Composer IO interface ( Composer\IO\IOInterface )

This gives you access to things like package names, options passed to the command, and allows for more robust scripting inside your app context.

Make sure your autoloader includes the namespace where your handler lives so Composer can find and execute it.

Testing and Debugging Your Scripts

It's easy to break things with custom scripts, especially when deploying to production or CI environments. To test locally:

1. Run composer install or update manually and watch output.
2. Use echo or logging to see if your script ran.
3. Check return codes—if a script exits with non-zero status, Composer treats it as a failure.

Also, keep in mind:

• Scripts are inherited by dependent packages, so be careful not to override someone else's without good reason.
• Avoid long-running processes unless necessary; Composer expects scripts to finish quickly.

Basically that's it. Hooking into Composer events via scripts is straightforward once you know the event names and how to structure the composer.json . Whether you're calling simple shell commands or full PHP classes, it's a powerful way to tie your project's behavior into dependency management.

The above is the detailed content of How do I hook into Composer events using scripts?. For more information, please follow other related articles on the PHP Chinese website!