Theory bits for a workshop about Symfony 4. Workshop steps and exercises are in http://symfony4.limenius.com/

1. Symfony 4
Workshop
Victoria Quirante - @vicqr
Nacho Martin - @nacmartin
Notes: http://symfony4.limenius.com/

2. Nacho Martín
@nacmartin
nacho@limenius.com
Victoria Quirante
@vicqr
victoria@limenius.com
We build tailor-made projects with Symfony and React
We have been working with Symfony since 2008
We provide development, consulting and training

3. Symfony 4

4. We are here

5. Symfony Evolution
Symfony 12005 A monolith (very different)
Symfony 22011 Components appear

6. Components used in popular projects

7. Doctrine

8. Silex

9. Laravel

10. Symfony Evolution
Symfony 12005 A monolith (very different)
Symfony 22011 Components appear
Symfony 32015 Brief intermediate step
Symfony 42017 Compose your apps

11. Symfony 2/3
SF 2
Web app
SF 2
API
SF 2
Microservice
SF 4
Web app
SF4
API
SF4
Microservice
Symfony 4

12. Symfony 4
SF4 SF 4
Web app
SF4
API
SF4
Microservice
We need something to smooth
out these transformations

13. Symfony Flex

14. Symfony Flex is a tool to implement
Symfony 4 philosophy

15. It is a composer plugin that comes with
Symfony 4
The idea is automation to the max
when installing and configuring packages

16. Modifies the behaviour of the
require and update commands
Allows Symfony to perform tasks before
or after the composer commands

17. Symfony 4
Your application
with Symfony Flex
composer req mailer
Symfony Flex
Server
Recipe?
No
Regular install
With composer

18. Symfony 4
Your application
with Symfony Flex
composer req mailer
Symfony Flex
Server
Recipe?
Yes
Install them
With composer
Follow recipe instructions
Decide which packages to install
Run any task to configure them

19. http://symfony.sh

20. Directory Structure
my-project/
├── config/
│ ├── bundles.php
│ ├── packages/
│ ├── routes.yaml
│ └── services.yaml
├── public/
│ └── index.php
├── src/
│ ├── ...
│ └── Kernel.php
├── templates/
└── vendor/

21. Doctrine

22. Entity

23. Entity
namespace AppEntity;
class Movie
{
private $id;
private $name;
private $director;
private $year;
private $picture;
}

24. Entity /**
* @ORMEntity()
* @ORMTable(name="movie")
*/
class Movie
{
/**
* @ORMColumn(type="integer")
* @ORMId
* @ORMGeneratedValue(strategy="AUTO")
*/
private $id;
/**
* @ORMColumn(type="string")
*/
private $name;
/**
* @ORMColumn(type="string", length=100)
*/
private $director;
/**
* @ORMColumn(type="smallint")
*/
private $year;
/**
* @ORMColumn(type="string")
*/
private $picture;
}

25. Entity
Code that has to do with the model itself.
Doesn’t depend on services, or query the DB.

26. Accessors
In this workshop we are going to use setters and getters:
•getDirector()
•setDirector()
This is not the only way. See for instance:
http://williamdurand.fr/2013/08/07/ddd-with-symfony2-folder-structure-and-code-first/

27. Entity Manager

28. Entity Manager
$em = $this->getDoctrine()->getManager();
$em->getRepository(Movie::class)->find($movieId);
$em = $this->getDoctrine()->getManager();
$em->persist($sale);
$em->flush();

29. Doctrine Query Language (DQL)
$em = $this->getDoctrine()->getManager();
$query = $em->createQuery(
'SELECT m, a FROM App:Movie m LEFT JOIN m.actors a WHERE
m.id = :id'
)->setParameter('id', $movieId);
$movie = $query->getOneOrNullResult();

30. Query Builder
$em = $this->getDoctrine()->getManager();
$query = $em->getRepository(Movie::class)
->createQueryBuilder('m')
->select('m, a')
->leftJoin('m.actors', 'a')
->where('m.id = :id')
->setParameter('id', $movieId)
->getQuery();
$movie = $query->getOneOrNullResult();

31. Entity Manager
Code that deals with retrieving or persisting
entities.

32. Fixtures
With Alice

33. We could do this
for ($i = 0; $i < 10; $i ++) {
$movie = new Movie();
$movie->setYear(1994);
$movie->setName('Pulp Fiction'.$i);
//...
$em->persist($movie);
}
$em->flush();

34. With Alice
AppEntityMovie:
movie{1..10}:
name: '<sentence(4, true)>'
director: '<name()>'
year: '<numberBetween(1970, 2017)>'
picture: '<image("./public/images", 500, 500, "cats", false)>'
See all the generators in
https://github.com/fzaninotto/Faker

35. Relationships
appentitymovie:
actor{1..10}:
#…
movie{1..10}:
#...
actors: ["@actor<numberBetween(1, 3)>", "@actor<numberBetween(4, 6)>"]

36. Twig

37. Twig
{{ }}
{% %}
Display Data
Define Structures

38. Access variables
{{ foo }}
{{ foo.bar }}
{{ foo['bar'] }}

39. - Checks if foo is an array and bar an element
- If not, checks if foo is an object and bar a property
- If not, checks if foo is an object and bar a method
- If not, checks if foo is an object and getBar a method
- If not, checks if foo is an object and isBar a method
{{ foo.bar }}
Access variables

40. {% for user in users %}
{{ user.username }}
{% endfor %}
For each

41. {% for i in 0..10 %}
{{ i }}
{% endfor %}
For

42. For … else
{% for item in items %}
{{ item }}
{% else %}
No items.
{% endfor %}

43. <html><head>...</head>
<body>
<h1>
{% block title %}{% endblock %}
</h1>
{% block body %}{% endblock %}
</body></html>
Template inheritance
templates/layout.html.twig

44. {% extends "layout.twig" %}
{% block title %}
Home
{% endblock %}
{% block body %}
Lorem ipsum...
{% endblock %}
Template inheritance
templates/home.html.twig

45. {% extends "layout.twig" %}
{% block title %}
Movie list
{% endblock %}
{% block body %}
Duis aute irure dolor in..
{% endblock %}
Template inheritance
templates/movies.html.twig

46. Webpack
Encore

47. Webpack

48. Webpack
The standard nowadays.
Very powerful.
Steep learning curve.
Cons
Pros

49. Webpack Encore
A wrapper around Webpack that makes it
easier to set up.
It solves a big % of cases.
If you require something specific, you can still
use Webpack without Encore.

50. Forms

51. Create a form
$form = $this->createFormBuilder($task)
->add('task', TextType::class)
->add('dueDate', DateType::class)
->add('save', SubmitType::class, ['label' => 'Create Post'])
->getForm();
return $this->render('default/new.html.twig', [
'form' => $form->createView(),
]);

52. Forms in Twig
{{ form_start(form) }}
{{ form_widget(form) }}
{{ form_end(form) }}
You can customise a lot the rendering of every widget,
If you need to.

53. Handle submission
$form = $this->createFormBuilder($task)
->add('task', TextType::class)
->add('dueDate', DateType::class)
->add('save', SubmitType::class, ['label' => 'Create Task'])
->getForm();
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
$em = $this->getDoctrine()->getManager();
$em->persist($task);
$em->flush();
return $this->redirectToRoute('task_success');
}
return $this->render('default/new.html.twig', [
'form' => $form->createView(),
]);

54. Forms in their own classes
class TaskType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('task')
->add('dueDate', null, array('widget' => 'single_text'))
->add('save', SubmitType::class);
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'data_class' => Task::class,
));
}
}

55. Events

56. Event and EventListener
Event EventListener
dispatch

57. Event
class SaleEvent extends Event
{
const NAME = 'sale.created';
protected $sale;
protected $movie;
protected $numTickets;
public function __construct(Sale $sale, Movie $movie, int $numTickets)
{
$this->sale = $sale;
$this->movie = $movie;
$this->numTickets = $numTickets;
}
public function getSale()
{
return $this->sale;
}
public function getMovie()
{
return $this->movie;
}
public function getNumTickets()
{
return $this->numTickets;
}
}
A bag of parameters
that describe the event

58. Dispatch Events
$this->get('event_dispatcher')
->dispatch(
SaleEvent::NAME,
new SaleEvent($sale, $movie, $numTickets)
);

59. EventListener
Processes the event
class SaleListener
{
public function __construct(EntityManager $em)
{
$this->em = $em;
}
public function onSaleCreated(SaleEvent $event)
{
for ($i = 0; $i < $event->getNumTickets(); $i++) {
$ticket = new Ticket();
$ticket->setMovie($event->getMovie());
$ticket->setSale($event->getSale());
$ticket->setRow(1);
$ticket->setSeat(1);
$this->em->persist($ticket);
}
}
}

60. Services

61. Services
A service is an object that does something:
• Generate a thumbnail.
• Generate a PDF.
• A query to ElasticSearch.
• Log something.
• Send an email.

62. Example
class SaleLogger
{
private $logger;
public function __construct(LoggerInterface $logger)
{
$this->logger = $logger;
}
public function log(Sale $sale)
{
$this->logger->info('Sold ' . count($sale->getTickets()) . ' tickets to ' . $sale->getFullName());
}
}
Where does this come from?

63. Using services
public function listAction(SaleLogger $saleLogger)
{
//…
$saleLogger->log($sale);
}
Is injected with dependencies

64. Explicit configuration
# app/config/services.yml
services:
# explicitly configure the service
AppLoggerSaleLogger:
arguments:
$logger: '@monolog.logger.request'

65. Tagged services
$taggedServices = $container->findTaggedServiceIds(‘app.my_tag’);
foreach ($taggedServices as $id => $tags) {
$definition->addMethodCall('callAMethod', array(new Reference($id)));
}
AppMyServices:
resource: '../src/MyServices'
tags: ['app.my_tag']

66. Validation

67. Built in assertions
/**
* @ORMColumn(type="string")
* @AssertLength(min=2)
*/
private $fullName;
/**
* @ORMColumn(type="string")
* @AssertEmail()
*/
private $email;
/**
* @ORMColumn(type="text")
* @AssertLength(max=100)
*/
private $question;

68. Built in assertions
There are 47 assertions
From NotNull to Isbn
And we can write our
own assertions

69. Use validators
if ($form->isValid()) {}
$author = new Author();
$validator = $this->get('validator');
$errors = $validator->validate($author);
Dependency container

70. Standalone use
$email = ‘obama@usa.gov’;
$emailConstraint = new AssertEmail();
$emailConstraint->message = 'Invalid email address';
$errorList = $this->get('validator')->validate(
$email,
$emailConstraint
);

71. Creating new constraints
Constraint Validator
Validate

72. Constraint
class HasAvailableSeats extends Constraint
{
public $message = 'No {{ number }} available seats’;
protected $movie;
public function __construct($options)
{
$this->movie = $options['movie'];
}
public function getMovie()
{
return $this->movie;
}
public function validatedBy()
{
return get_class($this).'Validator';
}
}
No logic,
data that describes
the constraint
Who validates this?

73. class HasAvailableSeatsValidator extends ConstraintValidator
{
public function validate($value, Constraint $constraint)
{
$available = $constraint->getMovie()->getAvailableSeats();
if ($value > $available) {
$this->context->buildViolation($constraint->message)
->setParameter('{{ number }}', $value)
->addViolation();
}
}
}
Validator
Validation logic

74. APIs

76. Up to level 2
Good use of HTTP verbs (GET, POST, PUT, DELETE, PATCH…)
Structure based on resources (/movies, /movies/31).
Use of HTTP Status codes (200, 201, 406, …).
Use of representations (JSON, XML, …).

77. Serializer: the idea
$recipe = new Recipe();
$recipe->setName($content['name']);
$recipe->setEnergy($content['energy']);
$recipe->setServings($content['servings']);
Request->Our object (manual deserialization)
$responseData = [
'id' => $recipe->getId(),
'name' => $recipe->getName(),
'energy' => $recipe->getEnergy(),
'servings' => $recipe->getServings(),
];
$response = new JsonResponse($responseData, 201);
Our object->Request (manual serialization)
Tedious!

78. $response = new Response($serializer->serialize($recipe, 'json'), 201);
$responseData = [
'id' => $recipe->getId(),
'name' => $recipe->getName(),
'energy' => $recipe->getEnergy(),
'servings' => $recipe->getServings(),
];
$response = new JsonResponse($responseData, 201);
Our object->Request (manual serialization)
Serialize

79. $recipe = $serializer->deserialize($content, Recipe::class, 'json');
$recipe = new Recipe();
$recipe->setName($content['name']);
$recipe->setEnergy($content['energy']);
$recipe->setServings($content['servings']);
Request->Our object (manual deserialization)
Deserialize

80. Serializer

81. Representation in API != DB
{
id: 9,
name: "victoriaq",
password: "encryptedPassword",
email: "victoria@limenius.com",
avatar: "avatar.jpg",
twitter_handler: "vicqr",
profile: {
id: 19,
bio: "My bio."
}
}
I want this to be “username”
I don’t want to expose it!
Only in profile, not in list
We want to prepend “thumb_”
Only in version 2 of the API
I’d like this to be bio:”My bio”
We do this in the normalizer

82. Annotations
MaxDepth
• Detect and limit the serialization depth
• Especially useful when serializing large trees
Groups
• Sometimes, you want to serialize different sets of attributes from your entities
• Groups are a handy way to achieve this need

83. API Platform makes it very easy

84. Admin Panel

85. Admin on REST with API Platform

86. Sonata Admin

87. Easy Admin

88. Thanks! @nacmartin
nacho@limenius.com
@vicqr
victoria@limenius.com