This document provides an overview of key concepts in the Laravel PHP framework, including Lumen, middleware, dependency injection, filesystem/cloud storage, queues, task scheduling, databases, Eloquent ORM, and the LUCID architecture pattern. It discusses how Laravel supports middleware, dependency injection, filesystem abstraction, queueing, scheduling tasks, querying databases, migrations, seeding, and the Eloquent ORM. It also summarizes the LUCID architecture designed by Vinelab to improve code quality by defining features, jobs, services, and domains.

1. Building Scalable
applications with Laravel
Laravel - PHP Framework For Web Artisans

2. Lumen
The stunningly fast micro-framework by Laravel.
Lumen is the perfect solution for
building Laravel based
micro-services and blazing fast APIs

3. Laravel ● Middleware
● Dependency Injection
● Filesystem / Cloud Storage
● Queues
● Task Scheduling
● Database
○ Query Builder
○ Migrations
○ Seeding
● LUCID Architecture

4. Middleware
HTTP middleware provide a convenient mechanism for filtering
HTTP requests entering your application.
● Maintenance
● Authentication
● CSRF protection
MeetingMogul
Validate twilio requests (Header Signature)

5. <?php
namespace AppHttpMiddleware;
use Log;
use Closure;
use AppRepositoriesTwilioAccountTwilioAccountRepositoryInterface;
class ValidateTwilioRequestMiddleware
{
/**
* Handle an incoming request.
*
* @param IlluminateHttpRequest $request
* @param Closure $next
* @return mixed
*/
public function handle($request, Closure $next)
{
if (!$this->validateRequest($request)) {
throw new SymfonyComponentHttpKernelExceptionUnauthorizedHttpException('Twilio', 'You are not authorized to access this
resource.');
}
return $next($request);
}
}

6. Dependency Injection
Laravel provides a convenient way to inject dependencies
seemlessly.
<?php
namespace Database;
class Database
{
protected $adapter;
public function __construct(AdapterInterface $adapter)
{
$this->adapter = $adapter;
}
}

7. <?php
namespace AppApiv1Controllers;
use AppApiTransformersMessageStatusTransformer;
use AppRepositoriesUserUserRepositoryInterface;
/**
* Message Resource
*
* @Resource("Message", uri="/messages")
*/
class MessageController extends BaseController
{
protected $userRepo;
public function __construct(Request $request, UserRepositoryInterface $userRepo)
{
parent::__construct($request);
$this->userRepo = $userRepo;
}
protected function setMessagingStatus(Request $request)
{
$this->userRepo->createOrUpdateProfile($this->auth->user(), $request->all());
return (['message' => 'Message Status updated successfully.']);
}
}

8. <?php
namespace AppRepositories;
use IlluminateSupportServiceProvider;
class RepositoryServiceProvider extends ServiceProvider
{
/**
* @var array
*/
protected $bindings = [
UserUserRepositoryInterface::class => UserUserRepository::class,
BuddyBuddyRepositoryInterface::class => BuddyBuddyRepository::class,
ProfileProfileRepositoryInterface::class => ProfileProfileRepository::class,
ContentContentRepositoryInterface::class => ContentContentRepository::class,
];
/**
* @return void
*/
public function register()
{
foreach ($this->bindings as $interface => $implementation) {
$this->app->bind($interface, $implementation);
}
}
}

9. Cloud Storage
Laravel provides a powerful filesystem abstraction. It
provides simple to use drivers for working with Local
filesystems, Amazon S3 and Rackspace Cloud Storage. Even
better, it's amazingly simple to switch between these
storage options as the API remains the same for each system.

10. Cloud Storage
public function updateAvatar(Request $request, $id)
{
$user = User::findOrFail($id);
Storage::put(
'avatars/'.$user->id,
file_get_contents($request->file('avatar')->getRealPath())
);
}

11. Queues
The Laravel queue service provides a unified API across a
variety of different queue back-ends.
$job = (new SendReminderEmail($user))->onQueue('emails');
$this->dispatch($job);
Available Queue Drivers:
Database, Beanstalkd, Amazon SQS, Redis, and synchronous
(for local use) driver

12. Task Scheduling
The Laravel command scheduler allows you to fluently and
expressively define your command schedule within Laravel
itself, and only a single Cron entry is needed on your
server.
protected function schedule(Schedule $schedule)
{
$schedule->call(function () {
DB::table('recent_users')->delete();
})->daily();
$schedule->command('emails:send')->weekly()->mondays()->at('13:00');
$schedule->command('emails:send')->withoutOverlapping();
}

13. Database
Query Builder
Migrations
Seeding
Elequent ORM

14. Query Builder
DB::transaction(function () {
DB::table('users')->update(['votes' => 1]);
DB::table('posts')->delete();
});

15. Migrations
Migrations are like version control for your database.
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
});

16. Seeding
Laravel includes a simple method of seeding your database
with test data using seed classes.
<?php
use IlluminateDatabaseSeeder;
use IlluminateDatabaseEloquentModel;
class DatabaseSeeder extends Seeder
{
public function run()
{
DB::table('users')->insert([
'name' => str_random(10),
'email' => str_random(10).'@gmail.com',
'password' => bcrypt('secret'),
]);
}
}

17. Eloquent ORM
● Convention over configuration
● Timestamps automatically managed (Carbon)
● Soft Deleting
● Query Scopes

18. Eloquent ORM - Soft Delete
● Active Record implementation
php artisan make:model User --migration
<?php
namespace App;
use IlluminateDatabaseEloquentModel;
use IlluminateDatabaseEloquentSoftDeletes;
class Flight extends Model
{
use SoftDeletes;
/**
* The attributes that should be mutated to dates.
*
* @var array
*/
protected $dates = ['deleted_at'];
}

19. LUCID
Architecture
An Architecture is a pattern of
connected Structures.
LUCID architecture Designed at vinelab
to get rid of rotting/legacy code.

20. Architecture

21. Controller View
Model
Service/
Domain
Communicate Structures

22. ● No more legacy code
● Defines Terminology
● Comprehensive, No limitations
● Complements Laravel’s Design
● Balance performance and design

23. Lucid Components
Feature
Job
Service

24. Lucid * Feature
● As described in business, as a class name
● Runs Jobs - Steps in the process of accomplishment
CreateArticleFeature
LoginUserFeature
Controller Feature
Serves

25. Controller serves Feature

30. Lucid * Job
A class that does one thing; responsible for the business logic
● Validate Article Input
● Generate Slug
● Upload Files To CDN
● Save Article
● Respond With Json
CreateArticleFeature

31. Lucid * Job
A class that does one thing; responsible for the business logic
● ValidateArticleInputJob
● GenerateSlugJob
● UploadFilesToCDNJob
● SaveArticleJob
● RespondWithJsonJob
CreateArticleFeature

32. Lucid * Job
A class that does one thing; responsible for the business logic

37. Lucid * Service
Implements Features and serves them through controllers
● Website
● Api
● Backend

40. Lucid * Domains
Responsible for the entities; exposing their
functionalities through Jobs

41. Lucid * Domains
● Article
○ GetPublishedArticlesJob
○ SaveArticleJob
○ ValidateArticleInputJob
● CDN
○ UploadFilesToCdnJob
● HTTP
○ RespondWithJsonJob

43. Lucid * Principles
● Controllers serve Features
● Avoid Cross-Domain Communication
● Avoid Cross-Job Communication

44. Best Practices
● Standards (PHP-FIG)
○ Autoloading
○ Code Style
● Interfaces
● Components
○ Carbon
○ Intervention
● Pull Requests &
● Code Reviews on GitHub

45. Question & Answer