https://github.com/norzechowicz/mydrinks

1. Albert Einstein
Learn from yesterday,
live for today,
hope for tomorrow.
The important thing
is not to stop questioning.
„

2. Test Driven
Development
Behavior Driven
Development
Domain Driven
Design

3. Test Driven
Development
Behavior Driven
Development
Domain Driven
Design

4. Don’t think about
that now

5. Architecture

6. Inspired by Shrek (and drugs ;)
Ogres
and Applications
are like onions

7. • Domain
• Application
• Infrastructure
• User Interface
They both have layers!

8. A long time ago in a bar
far, far away…

10. It is all about
Recipe

11. Let’s make
an App
for that

12. but…
explore
the domain
first!

13. 48 hours later…

14. Version 1.0 features
• recipes search engine
• recipe drink photos
• ingredients list
• possibility to add new recipes (admin only)
• comments
• social media stufff

15. Domain
1

16. Examples

17. Feature: Create new drink recipe
Scenario: Create new drink recipe
Scenario: Attempt to create new drink recipe using too many liquids
Scenario: Attempt to create new drink without glass
Scenario: Attempt to add step about pouring to shaker without shaker
Scenario: Attempt to remove significant step from the recipe

18. /**
* @When I decide to create new recipe called :name
*/
public function iDecideToCreateNewRecipeCalled($name)
{
$this->recipe = new Recipe(new Name($name));
}
/**
* @When as first step I add: prepare :name glass with :capacity ml capacity
*/
public function asFirstStepIAddPrepareHighballGlassWithMlCapacity($name, $capacity)
{
$this->recipe->prepareTheGlass(new Name($name), new Capacity($capacity));
}
Modeling by examples

19. Im not sure
but something
is wrong here

20. Let’s try
with SPECS

21. RecipeSpec.php
it_has_a_name();
it_requires_preparing_a_glass_as_a_first_step();
it_allows_pouring_into_prepared_glass();
it_allows_filling_prepared_glass();
it_allowes_adding_ingredients_into_glass();
it_does_not_have_any_description_by_default();

22. GlassSpec.php
it_has_a_name();
it_is_standalone_by_default();
it_has_a_capacity();
it_can_be_filled_with_liquids();
it_cant_be_over_filled();
it_allows_to_stir_liquids();

23. IngredientSpec.php
CapacitySpec.php
AmountSpec.php
RecipeDescriptionSpec.php
Other SPECS

24. • Value Objects
• Entities
• Services
• Aggregates

25. Make it
SOLID
Single responsibility principle |
Open/closed principle | Liskov
substitution principle | Interface
segregation principle |
Dependency inversion principle |
Single responsibility principle |
Open/closed principle | Liskov
substitution principle | Interface
segregation principle |
Dependency inversion principle |
Single responsibility principle |
Open/closed principle | Liskov
substitution principle | Interface
segregation principle |
Dependency inversion principle |
Single responsibility principle |
Open/closed principle | Liskov
substitution principle | Interface
segregation principle |
Dependency inversion principle |
Single responsibility principle |
Open/closed principle | Liskov
substitution principle | Interface
segregation principle |
Dependency inversion principle |

26. Make it
Unbreakable

27. Domain (model)

28. 2 Application

29. Think like a
programmer

30. Talk to me

31. • CreateNewRecipeCommand.php
• AddRecipeStepCommand.php
• RemoveRecipeStepCommand.php
• UpdateRecipeDescriptionCommand.php
• UploadRecipePhotoCommand.php
• PublishRecipeCommand.php

32. • Create New Recipe
• Add Recipe Step
• Remove Recipe Step
• Update Recipe Description
• Upload Recipe Photo
• Publish Recipe

33. • CreateNewRecipeCommand.php
• AddRecipeStepCommand.php
• RemoveRecipeStepCommand.php
• UpdateRecipeDescriptionCommand.php
• UploadRecipePhotoCommand.php
• PublishRecipeCommand.php

34. • Search Engine
• Autocomplete (Ingredients)
• Recipes Collection (Repository)
Well, sometimes
you have to ask…?

35. • Command Bus
• Command Handlers
• Recipe Serializer
Other things
• Filesystem
• SlugGenerator

36. <?php
class CreateNewRecipeCommand
{
/**
* @var string
*/
private $name;
/**
* @param string $name
*/
public function __construct($name)
{
$this->name = $name;
}
/**
* @return string
*/
public function name()
{
return $this->name;
}
}

37. Immutable
commands

38. <?php
class CreateNewRecipeHandler
{
private $recipes;
private $recipeFactory;
public function __construct(Recipes $recipes, Factory $recipeFactory)
{
$this->recipes = $recipes;
$this->recipeFactory = $recipeFactory;
}
public function handle(CreateNewRecipeCommand $command)
{
$recipe = $this->recipeFactory->createRecipe($command->name());
if ($this->recipes->hasRecipeWithName($recipe->getName())) {
throw new RecipeAlreadyExistsException();
}
$this->recipes->add($recipe);
}
}

39. Wait
a minute…

40. <?php
/**
* @When I decide to create new recipe called :name
*/
public function iDecideToCreateNewRecipeCalled($name)
{
$command = new CreateNewRecipeCommand();
$command->name = $name;
$this->commandBus->handle($command);
$this->currentRecipeName = new Name($name);
}
/**
* @When as first step I add: prepare :name glass with :capacity ml capacity
*/
public function asFirstStepIAddPrepareHighballGlassWithMlCapacity($name, $capacity)
{
$command = new AddRecipeStepCommand();
$command->slug = $this->slugGenerator->generateFrom($this->currentRecipeName);
$command->action = RecipeActions::PREPARE_GLASS;
$command->name = $name;
$command->capacity = (int) $capacity;
$this->commandBus->handle($command);
}

41. Well done!

42. Application

43. 3 Infrastructure

44. Just implement
interfaces

45. • FlySystemFilesystem
• InMemoryRepository
• FilesystemRepository
• SlugifySlugGenerator
• JsonSerializer
• ElasticSearchEngineAdapter
• DummySearchEngineAdapter

46. Interface

47. LEGO
Power Functions - Engine
Implementation

48. Literally nothing
for testing purpose only
Dummy
implementation

49. 4 User Interface

50. Connection
between
user and
application

51. Framework
based

52. • ROUTING
• TEMPLATING ENGINE
• SERVICE LOCATOR
• FORMS
• VALIDATION
• REQUEST RESPONSE WRAPPERS

53. Symfony 2

54. Laravel

55. Zend 2

56. Hybride?

57. Symfony 2 + Laravel?
Maybe with
shared service locator

58. • WEB APPLICATION
• CONSOLE APPLICATION
• REST API
• SOAP API
• GUI
Examples

59. User Interface

60. 5 System

61. DOMAIN
APPLICATION
USER INTERFACE
I
N
F
R
A
S
T
R
U
C
T
U
R
E

62. System

63. My Drinks v 1.0
160 working hours
1 developer

64. A walk through
system layers
Story written by alcohol

65. http://twitter.com/norzechowicz
http://github.com/norzechowicz
norbert@orzechowicz.pl
http://phpers.pl
Norbert
Orzechowicz

66. https://github.com/norzechowicz/mydrinks
My Drinks Repository

67. http://zawarstwaabstrakcji.pl

68. Questions?