PHP Belfast Laravel Presentation

A brief introduction to the Laravel PHP framework and its key features.

Transcript

1. Text PHP Belfast Laravel Presentation By David Frame
2. About me Started using PHP around 1999-2000. Primarily interested in OOP, design patterns, frameworks, CMS development and R&D. Research Developer at Tibus / Simply Zesty (2003-2012). Senior Developer at Blue Cube / AV Browne (2013). Senior Developer at 31interactive (2013-present).
3. The PHP Renaissance Better internals (namespaces, closures, traits, etc). Better tools (Composer, CLI utilities). Better methodologies (OOP, TDD, DI). Better standards (PSR). Better frameworks (Symfony2, ZF2, Slim, Aura, Laravel).
5. About this presentation It's a VERY brief introduction! Covers Laravel's six main elements as I see them. Will hopefully prompt you to learn more about it. It's not a sermon!
6. So what is Laravel? A modern PHP 5.3+ full-stack framework first released in July 2011. Very loosely based off Codeigniter. Makes use of several popular and highly tested components such as Symfony's HttpKernel & HttpFoundation, Monolog, Swiftmailer, etc.
8. The six areas I'll be covering 1. Syntax. 2. Artisan command line tool. 3. Request routing. 4. Query Builder & Eloquent database layers. 5. Blade templating engine. 6. IoC container.
9. 1. Syntax
10. Expressiveness $articles = Article::where('online', '=', 1) ->orderBy('date', 'desc') ->skip(10) ->take(5) ->get(); Redirect::to('login') ->with('message', 'Login failed'); Cookie::forever('remember_me', 1);
11. Facades Facades are static wrappers to instantiated objects. They provide a quick, readable way to access Laravel's various components. Big misconception: Laravel is NOT a static framework. Since these facades are syntactic sugar you can bypass them for mocks and tests! You can easily create your own facades or 'rewire' the existing ones.
12. Facades example $appName = Config::get('application.name'); $filesystem = new Filesystem(...); $fileloader = new Fileloader($filesysyem); $config = new Config($fileloader, 'dev'); $appName = $config->get('application.name');
13. 2. Artisan
14. Powerful command line tool Based off Symfony's Console component. Allows a number of application management tasks to be run from the CLI (code generation, DB migrations, etc). Easily customisable - write your own tasks!
15. Text Interactive shell (Tinker)
16. Text Custom mailer command
17. 3. Request routing
18. Implicit routing Route::get('news', function() { return '<p>News page</p>'; }); Route::get('news/{id}', function($id) { return '<p>Article with id ' . $id . '</p>'; })->where('id', '[0-9]+'); Route::post('enquiry/submit', function() { return 'Posted: ' . print_r($_POST, true); });
19. Routing to controllers Route::controller('news', 'NewsController'); Route::controller('login', 'LoginController'); Route::controller('admin', 'AdminController'); class NewsController { public function getIndex() { ... } public function getArticle() { ... } public function postComment() { ... } }
20. Routing to resources (REST) Route::resource('news', 'NewsController'); class NewsController { public function index() { ... } public function create() { ... } public function store() { ... } public function show() { ... } public function edit() { ... } public function update() { ... } public function destroy() { ... } }
21. Resource routes -> methods GET /news -> NewsController::index() GET /news/create -> NewsController::create() POST /news -> NewsController::store(); GET /news/{id} -> NewsController::show($id) GET /news/{id}/edit -> NewsController::edit($id) PUT/PATCH /news/{id} -> NewsController::update($id) DELETE /news/{id} -> NewsController::destroy($id) For the previous NewsController route we would have:
22. Route names & filters Route::get('news/{id}', array('as' => 'article', function() { return '<p>News article!</p>'; }}); ! Redirect::route('article', array('id' => 1)); Route::filter('auth', function() { if (Auth::guest()) { return Redirect::to('login'); } }); ! Route::get('admin', array('before' => 'auth', function() { return '<p>Welcome to the admin area!</p>'; }));
23. 4. Query Builder and Eloquent
24. Query Builder A feature-rich database abstraction layer implemented using PDO. Allows you to manipulate a database using object methods calls or using raw SQL. Fluent interface (chainable methods). Clean, English-like syntax. Supports 'complicated' database operations such as joins, aggregates, unions and even caching. Comparable to Zend\Db\Sql, Pear's MDB2 package.
25. Selects and Inserts DB::table('posts')->where('online', '=', 1) ->orderBy('date', 'desc')->take(5)->get(); DB::table('posts')->where('id', '=', 15)->first(); DB::table('posts')->insert(array( 'title' => 'Test Article', 'date' => '2013-11-05', 'online' => 1 ));
26. Updates and Deletes DB::table('posts') ->where('id', '=', 15) ->update(array( 'title' => 'Updated Test Article', 'online' => 0 ) ); DB::table('posts') ->where('id', '=', 15) ->delete();
27. Other handy features DB::table('posts')->where('id', '=', 15) ->pluck('title'); DB::table('posts') ->join('categories', 'posts.category_id', '=', 'categories.id') ->where('categories.id', '=', 5) ->get(); DB::table('reviews')->avg('rating');
28. Eloquent Object Relational Mapper built on top of Query Builder - it has identical syntax! Allows database entities to be mapped to PHP code, commonly referred to as Models. A model definition can be quickly set up using an appropriately named class (no getter/setters required!) Powerful features such as relationships, eager loading, event triggers, accessors/mutators and a lot more! Comparable to Zend\Db\TableGateway, Doctrine, Propel, Redbean.
29. Model Class class Post extends Eloquent { } class Post extends Eloquent { protected $table = 'newsposts'; public function summary() { return truncate($this->content, 150); } }
30. Selects and Inserts Post::where('date', '<=', DB::raw('CURDATE()')) ->andWhere('online', '=', 1) ->get(); Post::find(5); $post = new Post(); $post->title = 'New Article'; $post->date = new DateTime(); $post->online = true; $post->save();
31. Updates, Deletes & Conversions $post = Post::find(5); $post->title = 'Updated News Article'; $post->online = false; $post->save(); Post::find(5)->delete(); // Or... Post::destroy(5); Post::all()->toArray(); Post::find(5)->toJson();
32. Relationship definition class Post extends Eloquent { public function comments() { return $this->hasMany('Comment'); } } ! ! class Comment extends Eloquent { public function post() { return $this->belongsTo('Post'); } }
33. Relationship usage $post = Post::find(5); echo '<h2>' . $post->title . '</h2>'; foreach ($post->comments as $comment) { echo ' <p>' . $comment->text . '</p> <p>' . $comment->author . '</p> '; } $comment = Comment::find(25); echo '<h2>' . $comment->post->title . '</h2>';
34. Quick and easy Pagination $posts = Post::paginate(10); ... Produces Bootstrap-compatible paging links! foreach ($posts as $post) { echo '<h2>' . $post->title . '</h2>'; echo '<p>' . $post->summary . </p>'; } ! echo $posts->links();
35. 5. Blade
36. Overview Blade is a quick and relatively simple template engine for rendering your views. Features many of the core functions found in other popular engines such as Twig and Smarty. Since Blade views are PHP scripts, you can use PHP code directly in your templates (with caution!) Inheritance-driven to allow for multiple layouts, sections, etc.
37. Basic template @include('inc/header') ! <h1>{{{ $pageTitle }}}</h1> ! <p>{{ count($posts) }} articles to display!</p> ! @foreach ($posts as $post) <h2>{{{ $post->title }}}</h2> @if ($post->summary) <p>{{{ $post->summary }}}</p> @endif @endforeach ! @include('inc/footer');
38. Rendering a view Route::get('news', function() { ! $posts = Post::all(); ! return View.make('news') ->with('pageTitle', 'News') ->with('posts', $posts); ! }); Assuming that the template on the previous slide is named 'news.blade.php' we can do the following:
39. Layouts <html><body> <header>Site header goes here!</header> <div id="content"> @yield('content') </div> <footer>Site footer goes here!</footer> </body></html> @extends('layout') @section('content') <p>Welcome to the website!</p> @stop layout.blade.php home.blade.php
40. 6. IoC Container ? ? ? ? ? ? ? ? ? ? ?
41. A quick word on dependencies A dependency is when one component (typically an object) relies on another for its operation. Dependencies should be passed (injected) into an object via its constructor or setter methods and not instantiated inside it. Directly instantiating dependencies is considered bad practise as it reduces scalability and flexibility, plus it makes objects difficult to test in isolation.
42. Dependency examples class Computer { protected $processor; public function __construct() { $this->processor = new Processor\Intel\i7(); } } class Computer { protected $processor; public function __construct(ProcessorInterface $processor) { $this->processor = $processor; } } Bad Good
43. "In software engineering, inversion of control (IoC) is a programming technique, expressed here in terms of object-oriented programming, in which object coupling is bound at run time by an assembler object and is typically not known at compile time using static analysis." - Wikipedia So... IoC?
44. Forget the jargon! App::bind('shopping_basket', function($app) { return new ShoppingBasket( new Customer(), new DeliveryService\ParcelForce() ); }); The IoC container is a way of automatically passing dependencies into your objects and/or storing them for later retrieval. $shoppingBasket = App::make('shopping_basket');
45. Singletons App::singleton('user_session', function($app) { return new UserSession($_SESSION['REMOTE_ADDR']); }); We can treat the IoC container as a registry, initialising objects once and returning them on subsequent calls. // First call to App::make() creates the object... $userSession = App::make('user_session'); ! // Second call to App::Make() just fetches it... $sameUserSession = App::make('user_session');
46. IoC automatic resolution class Computer { protected $processor; public function __construct(ProcessorInterface $processor) { $this->processor = $processor; } } If you type-hint the dependencies passed into a constructor then Laravel can do the rest! $computer = App::make('Computer'); // Has i7 processor! App::bind('ProcessorInterface', 'Processor\Intel\i7');
47. IoC container + Facades = Laravel The static classes used to control Laravel are known as Facades. Facades are nothing more than wrappers to the IoC container. Therefore, every time you use a Facade such as DB, Config, View, Route, etc, you are creating and/or fetching a pre- registered object! You can easily create your own application-specific IoC bindings and Facades.
48. Further Resources Website and documentation: http://www.laravel.com GitHub: http://www.github.com/laravel/framework Laravel Ins and Outs: http://laravel.io Laracasts: http://www.laracasts.com Laravel Cheat Sheet: http://cheats.jesse-obrien.ca Leanpub: http://www.leanpub.com Twitter: @laravel, @taylorotwell, @jeffrey_way
49. Thanks for watching! Email: david@31interactive.com Twitter: @DaGrFr LinkedIn: http://linkedin.com/in/ dgframe Web: http://31interactive.com PHPBelfast: http://phpbelfast.com and on Twitter at @PHPBelfast