You’ve seen Kris’ open source libraries, but how does he tackle coding out an application? Walk through green fields with a Symfony expert as he takes his latest “next big thing” idea from the first line of code to a functional prototype. Learn design patterns and principles to guide your way in organizing your own code and take home some practical examples to kickstart your next project.

1. How Kris Writes Symfony Apps

2. @kriswallsmith

3. father artist bowhunter hacker
president widower gamer actor
tapdancer lover hater singer
writer founder yogi consultant
archer musician architect slacker
soccer player volunteer home
owner scotch drinker pianist…

4. assetic

5. Buzz

6. Spork

8. Getting Started

9. composer create-project !
symfony/framework-standard-edition !
widgets-by-kris/ !
~2.4

10. +
+
+
+
"doctrine/orm": "~2.2,>=2.2.3",!
"doctrine/doctrine-bundle": "~1.2",!
"doctrine/mongodb-odm-bundle": "~3.0",!
"jms/di-extra-bundle": "~1.4",!
"jms/security-extra-bundle": "~1.5",!
"jms/serializer-bundle": "~1.0",

11. ./app/console generate:bundle !
--namespace=Kris/Bundle/MainBundle

12. public function registerContainerConfiguration(LoaderInterface $loader)!
{!
$loader->load(__DIR__.'/config/config_'.$this->getEnvironment().'.yml');!
!
// load local_*.yml or local.yml!
if (!
file_exists($file = __DIR__.'/config/local_'.$this->getEnvironment().'.yml')!
||!
file_exists($file = __DIR__.'/config/local.yml')!
) {!
$loader->load($file);!
}!
}

13. Model

14. Treat your model like a princess.

15. She gets her own wing
of the palace…

16. doctrine_mongodb:!
auto_generate_hydrator_classes: %kernel.debug%!
auto_generate_proxy_classes:
%kernel.debug%!
connections: { default: ~ }!
document_managers:!
default:!
connection: default!
database:
kris!
mappings:!
model:!
type:
annotation!
dir:
%src%/Kris/Model!
prefix: KrisModel!
alias: Model

17. // repo for src/Kris/Model/Widget.php!
$repo = $this->dm->getRepository('Model:User');

18. …doesn't do any work…

19. use KrisBundleMainBundleCanonicalizer;!
!
public function setUsername($username)!
{!
$this->username = $username;!
!
$canonicalizer = Canonicalizer::instance();!
$this->usernameCanonical = $canonicalizer->canonicalize($username);!
}

20. use KrisBundleMainBundleCanonicalizer;!
!
public function setUsername($username, Canonicalizer $canonicalizer)!
{!
$this->username = $username;!
$this->usernameCanonical = $canonicalizer->canonicalize($username);!
}

21. …and is unaware of the work
being done around her.

22. public function setUsername($username)!
{!
// a listener will update the!
// canonical username!
$this->username = $username;!
}

23. Anemic domain model
is an anti-pattern?

24. Anemic???

25. “The fundamental horror of this anti-pattern is that it's
so contrary to the basic idea of object-oriented design;
which is to combine data and process together.”
!
Martin Fowler

26. $cabinet->open();

27. Cabinets don’t open themselves.

28. $asset->getLastModified();

29. Mapping Layers

30. thin

31. thin controller
fat model

32. MVC

33. Is Symfony an MVC framework?

34. HTTP

35. Application Land
Controller
HTTP Land

36. The controller is thin
because it maps from
HTTP-land to application-land.

37. What about the model?

40. public function registerAction()!
{!
// ...!
$user->sendWelcomeEmail();!
// ...!
}

41. public function registerAction()!
{!
// ...!
$mailer->sendWelcomeEmail($user);!
// ...!
}

42. Persistence Land
Model
Application Land

43. The model maps from
application-land to persistence-land.

44. Persistence Land
Model
Application Land
Controller
HTTP Land

45. Who lives in application land?

46. Thin controller, thin model…
Fat service layer!

47. Application Events

48. Use them.

49. That happened.

50. /** @DIObserve("user.username_change") */!
public function onUsernameChange(UserEvent $event)!
{!
$user = $event->getUser();!
$dm
= $event->getDocumentManager();!
!
$dm->getRepository('Model:Widget')!
->updateDenormalizedUsernames($user);!
}

51. One event class per model
•
•
•
Event name constants
Accepts object manager and object as arguments
Simple accessors

52. $event = new UserEvent($dm, $user);!
$dispatcher->dispatch(UserEvent::CREATE, $event);

53. $event = new UserUserEvent($dm, $user, $otherUser);!
$dispatcher->dispatch(UserEvent::FOLLOW, $event);

54. preFlush

55. public function preFlush(ManagerEventArgs $event)!
{!
$dm = $event->getObjectManager();!
$uow = $dm->getUnitOfWork();!
!
foreach ($uow->getIdentityMap() as $class => $docs) {!
if (is_a($class, 'KrisModelUser')) {!
foreach ($docs as $doc) {!
$this->processUserFlush($dm, $doc);!
}!
} elseif (is_a($class, 'KrisModelWidget')) {!
foreach ($docs as $doc) {!
$this->processWidgetFlush($dm, $doc);!
}!
}!
}!
}

56. /** @DIObserve("user.create") */!
public function onUserCreate(UserEvent $event)!
{!
$user = $event->getUser();!
!
$activity = new Activity();!
$activity->setActor($user);!
$activity->setVerb('register');!
$activity->setCreatedAt($user->getCreatedAt());!
!
$this->dm->persist($activity);!
}

57. /** @DIObserve("user.follow_user") */!
public function onFollowUser(UserUserEvent $event)!
{!
$event->getUser()!
->getStats()!
->incrementFollowedUsers(1);!
$event->getOtherUser()!
->getStats()!
->incrementFollowers(1);!
}

58. Decouple your application by
delegating work to clean, concise,
single-purpose event listeners.

59. Contextual Configuration

60. Save your future self a headache

61. # @MainBundle/Resources/config/widget.yml!
services:!
widget_twiddler:!
class: KrisBundleMainBundleWidgetTwiddler!
arguments:!
- @event_dispatcher!
- @?logger

62. JMSDiExtraBundle

63. /** @DIService("widget_twiddler") */!
class Twiddler!
{!
/** @DIInjectParams */!
public function __construct(!
EventDispatcherInterface $dispatcher,!
LoggerInterface $logger = null)!
{!
// ...!
}!
}

64. services:!
# aliases for auto-wiring!
container: @service_container!
dm: @doctrine_mongodb.odm.document_manager!
doctrine: @doctrine_mongodb!
dispatcher: @event_dispatcher!
security: @security.context

65. require.js

67. <script src="{{ asset('js/lib/require.js') }}"></script>!
<script>!
require.config({!
baseUrl: "{{ asset('js') }}",!
paths: {!
"jquery": "//ajax.googleapis.com/.../jquery.min",!
"underscore": "lib/underscore",!
"backbone": "lib/backbone"!
},!
shim: {!
"jquery": { exports: "jQuery" },!
"underscore": { exports: "_" },!
"backbone": {!
deps: [ "jquery", "underscore" ],!
exports: "Backbone"!
}!
}!
})!
require([ "main" ])!
</script>

68. // web/js/model/user.js!
define(!
[ "underscore", "backbone" ],!
function(_, Backbone) {!
var tmpl = _.template("<%- first %> <%- last %>")!
return Backbone.Model.extend({!
name: function() {!
return tmpl({!
first: this.get("first_name"),!
last: this.get("last_name")!
})!
}!
})!
}!
)

69. {% block head %}!
<script>!
require(!
[ "view/user", "model/user" ],!
function(UserView, User) {!
var view = new UserView({!
model: new User({{ user|serialize|raw }}),!
el: document.getElementById("user")!
})!
}!
)!
</script>!
{% endblock %}

70. Dependencies
•
•
•
model: backbone, underscore
view: backbone, jquery
template: model, view

71. {% javascripts!
"js/lib/jquery.js" "js/lib/underscore.js"!
"js/lib/backbone.js" "js/model/user.js"!
"js/view/user.js"!
filter="?uglifyjs2" output="js/packed/user.js" %}!
<script src="{{ asset_url }}"></script>!
{% endjavascripts %}!
!
<script>!
var view = new UserView({!
model: new User({{ user|serialize|raw }}),!
el: document.getElementById("user")!
})!
</script>

72. Unused dependencies
naturally slough off

73. JMSSerializerBundle

74. {% block head %}!
<script>!
require(!
[ "view/user", "model/user" ],!
function(UserView, User) {!
var view = new UserView({!
model: new User({{ user|serialize|raw }}),!
el: document.getElementById("user")!
})!
}!
)!
</script>!
{% endblock %}

75. /** @ExclusionPolicy("ALL") */!
class User!
{!
private $id;!
!
/** @Expose */!
private $firstName;!
!
/** @Expose */!
private $lastName;!
}

76. Miscellaneous

77. When to create a new bundle
•
•
•
Anything reusable
Lots of classes relating to one feature
Integration with a third party

78. {% include 'MainBundle:Account/Widget:sidebar.html.twig' %}

79. {% include 'AccountBundle:Widget:sidebar.html.twig' %}

80. Access Control

81. The Symfony ACL is for
arbitrary permissions

83. Encapsulate access logic in
custom voter classes

84. /** @DIService(public=false) @DITag("security.voter") */!
class WidgetVoter implements VoterInterface!
{!
public function supportsAttribute($attribute)!
{!
return 'OWNER' === $attribute;!
}!
!
public function supportsClass($class)!
{!
return is_a($class, 'KrisModelWidget');!
}!
!
public function vote(TokenInterface $token, $widget, array $attributes)!
{!
// ...!
}!
}

85. public function vote(TokenInterface $token, $widget, array $attributes)!
{!
$result = VoterInterface::ACCESS_ABSTAIN;!
if (!$this->supportsClass(get_class($widget))) {!
return $result;!
}!
!
foreach ($attributes as $attribute) {!
if (!$this->supportsAttribute($attribute)) {!
continue;!
}!
!
$result = VoterInterface::ACCESS_DENIED;!
if ($token->getUser() === $widget->getUser()) {!
return VoterInterface::ACCESS_GRANTED;!
}!
}!
!
return $result;!
}

86. JMSSecurityExtraBundle

87. /** @SecureParam(name="widget", permissions="OWNER") */!
public function editAction(Widget $widget)!
{!
// ...!
}

88. {% if is_granted('OWNER', widget) %}!
{# ... #}!
{% endif %}

89. No query builders
outside of repositories

90. class WidgetRepository extends DocumentRepository!
{!
public function findByUser(User $user)!
{!
return $this->createQueryBuilder()!
->field('userId')->equals($user->getId())!
->getQuery()!
->execute();!
}!
!
public function updateDenormalizedUsernames(User $user)!
{!
$this->createQueryBuilder()!
->update()!
->multiple()!
->field('userId')->equals($user->getId())!
->field('userName')->set($user->getUsername())!
->getQuery()!
->execute();!
}!
}

91. Eager ID creation

92. public function __construct()!
{!
$this->id = (string) new MongoId();!
}

93. public function __construct()!
{!
$this->id = (string) new MongoId();!
$this->createdAt = new DateTime();!
$this->widgets = new ArrayCollection();!
}

94. Remember your
clone constructor

95. $foo = new Foo();!
$bar = clone $foo;

96. public function __clone()!
{!
$this->id = (string) new MongoId();!
$this->createdAt = new DateTime();!
$this->widgets = new ArrayCollection(!
$this->widgets->toArray()!
);!
}

97. public function __construct()!
{!
$this->id = (string) new MongoId();!
$this->createdAt = new DateTime();!
$this->widgets = new ArrayCollection();!
}!
!
public function __clone()!
{!
$this->id = (string) new MongoId();!
$this->createdAt = new DateTime();!
$this->widgets = new ArrayCollection(!
$this->widgets->toArray()!
);!
}

98. Save space on field names

99. /** @ODMString(name="u") */!
private $username;!
!
/** @ODMString(name="uc") @ODMUniqueIndex */!
private $usernameCanonical;

100. Only flush from the controller

101. public function theAction(Widget $widget)!
{!
$this->get('widget_twiddler')!
->skeedaddle($widget);!
$this->flush();!
}

102. No proxy objects

103. /** @ODMReferenceOne(targetDocument="User") */!
private $user;

104. public function getUser()!
{!
if ($this->userId && !$this->user) {!
throw new UninitializedReferenceException('user');!
}!
!
return $this->user;!
}

105. Questions?

106. @kriswallsmith.net
https://joind.in/10371
Thank You!