Composing a Better Phuture

Composer is both a dependency management and autoloader generation tool for PHP. This presentation highlights how and why we use Composer.

Transcript

1. Composing a Better Phuture by Jeremy Lindblom @jeremeamia
2. • Composer • Packages • SemVer • Autoloading • PSRs Composing a Better Phuture
3. But first, a history lesson. (Don’t worry, we’ll only cover a few years)
4. PHP is “mostly dead” 2008
5. is “mostly dead” 2008 2009 PHP 5.3.0 is released
6. ♥ for Git/GitHub grow 2010
7. PSR-0 & Composer 2011
8. HaPHPy 20th Birthday 2015
11. 1. Dependency Manager 2. Autoloader Generator What is Composer?
12. 1. Dependency Manager 2. Autoloader Generator What is Composer?
13. Dependency Management • Declare, resolve, and install project-specific dependencies • Use others’ code ◦ Use open source packages ◦ Focus on your biz features ◦ Avoid “NIH syndrome” • Create reusable packages in your own org
14. Before Composer • Compile PHP with extensions • System-level package managers • PEAR packages (system-system) • Include 3rd-party code in source • Git submodules Composer inspired by bundler and npm
15. getcomposer.org packagist.org
16. https://github.com/engrade/engrade-php-sdk/blob/master/composer.json Composer.json Example
17. Specifying Versions MAJOR.MINOR.PATCH (SemVer.org) “{vendor}/{package}”: “{version constraints}” • “>=3.1.4” – Use any version >= 3.1.4 • “3.1.*” – Use any patch version of 3.1 • “~3.2” – Use any 3.x version >= 3.2
18. Installing Composer curl -sS https://getcomposer.org/installer | php mv composer.phar /usr/local/bin/composer
19. Installing Your Dependencies For development: composer install and composer update For production: composer install --no-dev --optimize-autoloader
20. your-project-root/ |— src/ |— tests/ |— vendor/ |— composer.json |— composer.lock What does that do?
21. SHOULD YOU COMMIT YOUR composer.lock FILE? THE ANSWER MAY SHOCK YOU!
22. For Applications? ?
23. For Applications? YES!
24. For Applications? For Libraries? ? YES!
25. For Applications? For Libraries? Sure. YES!
26. How do you use your installed code? <?php require ‘vendor/autoload.php’; $client = new GuzzleHttp\Client(); $response = $client->get(‘http://example.com’);
27. 1. Dependency Manager 2. Autoloader Generator What is Composer?
28. — Includes —
29. a.php CODE CODE include ‘b.php’; CODE Includes = Why I Started Using PHP b.php CODE CODE CODE CODE Executed code CODE CODE CODE CODE CODE CODE CODE
30. Includes = Why I Started Using PHP header.php sidebar.php main.php
32. include include_once require require_once Including vs. Requiring What’s the difference between all of these?
33. Including Classes - Not Fun <?php // NOTE: Assuming one class per file require_once(‘classes/user.class.php’); require_once(‘classes/page.class.php’); require_once(‘classes/role.class.php’); require_once(‘classes/db.class.php’); // ...
34. The Bottom Line Explicit includes/requires are: 1. Necessary and helpful for procedural code. 2. Cumbersome and harmful for object- oriented code.
35. — Autoloaders —
36. What is an Autoloader? 1. A callback triggered when a non-existent class is referenced.
37. What is an Autoloader? 1. A callback triggered when a non-existent class is referenced. 2. A function that provides a definition for a specified class name.
38. Autoloader Advantages • Classes are loaded on demand ◦ No need to write specific include statements ◦ Class never loaded unless it’s needed • Leads to better code maintainability • Easy to write
39. Simple Autoloader Implementation class Autoloader { public function __construct($root) {...} public function load($class) { $path = $path->root; $path .= str_replace(‘\\’, ‘/’, $class); if (file_exists($path)) require $path; } }
40. Registering Autoloaders $loader = new Autoloader(__DIR__); spl_autoload_register([$loader, ‘load’]);
41. Autoloader Implementation Tips • You can have multiple autoloaders. • Don’t throw errors/exceptions if a file doesn’t exist. Let the other autoloaders try. • Don’t use the __autoload() function. • Use Composer’s autoloader. ◦ You don’t have to write your own ◦ It already follows the PSR autoloading standards
42. — PSRs & PHP-FIG —
44. • FIG = Framework Interop Group • PSR = PHP Standards Recommendation ◦ Autoloading: PSR-0, PSR-4 ◦ Others: ▪ PSR-1, PSR-2 - Coding style ▪ PSR-3 - Logging interface ▪ PSR-7 - HTTP message interface PHP-FIG
45. Autoloader Implementation Revisited class Autoloader { public function __construct($root) {...} public function load($class) { $path = $path->root; $path .= str_replace(‘\\’, ‘/’, $class); if (file_exists($path)) require $path; } }
46. Autoloader Implementation Revisited class Autoloader { public function __construct($root) {...} public function load($class) { $path = $path->root; $path .= str_replace(‘\\’, ‘/’, $class); if (file_exists($path)) require $path; } }
47. Class to load: Zend\Http\Client Include file: <source-root>/Zend/Http/Client.php Autoloading PSRs (PSR-0)
48. Source root base namespace: Zend\Http Class to load: Zend\Http\Client Include file: <source-root>/Client.php Autoloading PSRs (PSR-4)
49. Base Namespace in composer.json { ... "autoload": { "psr-4": { "Zend\\Http\\": "src/" } } }
50. — Optimization —
51. BAD GOOD There are many ways to implement autoloaders.
52. All classes in one file; no autoloader BAD GOOD
53. Many autoloaders; Each can only load 1 class BAD GOOD
54. BAD GOOD 2 1
55. BAD GOOD Composer autoloader (1 autoloader handles all classes)
56. BAD GOOD Composer optimized autoloader (1 autoloader; fast lookup; no file_exists)
57. Classmap Autoloading In your project root: composer install --no-dev --optimize-autoloader
58. Classmap Autoloading $paths = [...]; // class => file mappings if (isset($paths[$class])) require $paths[$class]; // vs. $path = $root . str_replace(‘\\’, ‘/’, $class); if (file_exists($path)) require $path;
59. One Autoloader to rule them all.
60. Composing a Better Phuture by Jeremy Lindblom @jeremeamia