2015 ZendCon - Service Oriented Architecture as a Pattern of Development

Transcript

1. SERVICE ORIENTED ARCHITECTURE
   AS
   A PATTERN OF DEVELOPMENT
   ZendCon 2015
   

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2. I AM MIKE WILLBANKS
   • Father, Husband, Developer
   • VP of Development at
   Packet Power
   • Twitter: @mwillbanks
   

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3. Applications much like onions,
   have multiple layers.
   

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4. A STORY
   

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5. ONCE UPON A TIME
   We wrote procedural code…
   

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6. 
   Recent Books
   
   
   $books = $db->select('...');
   foreach ($books as $book) {
   echo '' . $book['title'] . '';
   }
   ?>
   
   
   
   

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7. if ($_SERVER['REQUEST_METHOD'] == 'POST') {
   $db->insert('book', array(
   'title' => $_POST['title'],
   ));
   }
   ?>
   
   Add Book
   
   
   
   
   
   
   
   

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8. ALL WAS FINE
   IN THE
   WORLD
   Except for what was playing
   out before us…
   

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9. WE NEED
   LIBRARY
   The boss tells you it’s time for
   the library feature… and we
   need to update books.
   

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10. 
    My Libraries
    
    
    $libraries = $db->select('...');
    foreach ($libraries as $library) {
    echo '' .
    $library['name'] . '';
    }
    ?>
    
    
    
    

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11. if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    $db->insert('library', array(
    'name' => $_POST['name'],
    ));
    }
    ?>
    
    Add Library
    
    
    
    
    
    
    
    

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12. $rs = $db->select('...');
    $book = $rs[0];
    if ($book && $_SERVER['REQUEST_METHOD'] == 'POST') {
    $db->update('book', array(
    'library_id' => $_POST['library_id'],
    'title' => $_POST['title'],
    ), array(
    'book_id' => $book['id'],
    ));
    }
    $libraries = $db->select('...');
    ?>
    
    Update Book
    
    
    $libraries); ?>
    

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13. And these things continued…
    

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14. EVERYTHING IS FALLING APART
    

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15. BUGS
    All these little demons came out of the groundwork.
    

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16. #!/bin/bash
    grep -lri bookId * | wc -l
    $ 271
    

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17. REWRITE!
    Or I’m done!
    

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18. MVC
    Model View Controller
    Model
    Controller
    View
    

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19. MVC REQUEST LIFECYCLE
    

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20. CONTROLLERS
    • Send commands to the model and sends
    information to the view.
    • It’s where your request and response are handled.
    

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21. class BookController extends AbstractController {
    public function addAction() {
    $book = $this->model->insert(array(
    'title' => $this->getPost('title')
    ));
    return array(
    'book' => $book
    );
    }
    }
    

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22. MODELS
    • Handles the state,
    persistence, data access and
    more.
    • Might have mappers and
    entities, it might not..
    • It’s a loaded term.
    

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23. class BookModel extends AbstractModel {
    public function insert(array $book) {
    $book['id'] = $this->db->insert('book',
    $book);
    return $book;
    }
    }
    

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24. class BookModel extends AbstractModel {
    public function getId();
    public function setId($id);
    public function getTitle();
    public function setTitle($title);
    }
    

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25. class BookModelMapper extends AbstractMapper {
    public function save(BookModel $book);
    public function find($id);
    public function fetchAll();
    }
    

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26. VIEWS
    • Separating display from business logic
    • Escaping and handling what our controller is
    providing
    

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27. $this->layout('main');
    ?>
    
    
    escape($book->getTitle());?>
    li>
    
    
    

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28. THERE IS A
    BETTER WAY.
    

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29. SOA
    Service Oriented Architecture
    Service Layer
    Controller
    View
    Domain Models
    Data Mappers
    Data Access Objects
    Model
    

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30. BENEFITS OF A SERVICE LAYER
    • Better Controllers
    • Better Maintainability
    • Better Parallelism in
    Development
    • Better Testing/Fewer
    Defects
    • More Reuse
    

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31. LETS GET BUILDING
    

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32. BASIC PRINCIPLES
    

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33. CONTROLLERS
    Exactly like MVC, but injecting a service layer.
    

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34. class BookController extends AbstractController {
    public function addBookAction() {
    $book = $this->bookService->addBook(
    $this->getPost('isbn'),
    $this->getPost('title'),
    $this->getPost('description')
    );
    return $this->redirect('/book/' . $book-
    >getId());
    }
    }
    

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35. SERVICES
    • Your application logic /
    business functionality
    • The in-between layer
    • The internal API to your
    application
    

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36. – Wikipedia http://en.wikipedia.org/wiki/Service_(systems_architecture)
    “A set of related software functionalities that can be
    reused for different purposes.”
    

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37. class BookService extends AbstractService {
    public function addBook($isbn, $title,
    $description) {
    $book = new BookEntity();
    $book->setIsbn($isbn);
    $book->setTitle($title);
    $book->setDescription($description);
    $this->mapper->addBook($book);
    return $book;
    }
    }
    

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38. DOMAIN
    MODELS
    • Describe a “thing”
    • Data object
    • Domain logic
    • Generally getters, setters
    

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39. class Book extends AbstractEntity {
    public function getId();
    public function setId($id);
    public function getIsbn();
    public function setIsbn($isbn);
    public function getTitle();
    public function setTitle($title);
    public function getDescription();
    public function setDescription($description);
    }
    

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40. FILTERING AND VALIDATION
    • Always filter
    • User data to be validated.
    

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41. class Book extends AbstractEntity {
    public function getTitle();
    public function setTitle($title) {
    $trim = new TrimFilter();
    $title = $trim->filter($title);
    $this->title = title;
    return $this;
    }
    }
    

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42. class Book extends AbstractEntity {
    pubic function getTitle();
    public function setTitle($title) {
    $trim = new TrimFilter();
    $title = $trim->filter($title);
    $validate = new AlnumValidator();
    if (!$validate->isValid($title)) {
    throw new
    InvalidArgumentException($validate->getMessage());
    }
    $this->title = title;
    return $this;
    }
    }
    

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43. INPUT FILTER
    PATTERN
    Merge filters and validators
    

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44. class Book extends AbstractEntity {
    public function getInputFilter() {
    $input = new Input('title');
    $input->getFilterChain()
    ->attachByName('stringtrim')
    ->attachByName('alphanumeric');
    $input->getValidatorChain()
    ->attachByName('not_empty')
    ->attachByName('string_length',
    array('min' => 1, 'max' => 45));
    $this->inputFilter->addInput($input);
    return $this->inputFilter;
    }
    }
    

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45. class Book extends AbstractEntity {
    public function getTitle();
    public function setTitle($title) {
    $inputFilter = $this->getInputFilter()-
    >getInput('title');
    $inputFilter->setValue($title);
    if ($inputFilter->isValid()) {
    $this->title = $title;
    }
    throw new
    InvalidArgumentException($inputFilter-
    >getMessages());
    }
    }
    

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46. DATA
    MAPPERS
    • Separates mapping data to
    a data store as well as your
    data model.
    • Data store can be anything
    or even multiple things.
    

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47. class BookMapper extends AbstractMapper {
    public function addBook(BookEntity $book) {
    $this->repository->save($book);
    return $book;
    }
    }
    

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48. But I have multiple tables for this entity!!!
    

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49. class Book extends AbstractEntity {
    public function getId();
    public function setId($id);
    public function getIsbn();
    public function setIsbn($isbn);
    public function getTitle();
    public function setTitle($title);
    public function getDescription();
    public function setDescription($description);
    }
    class Book extends AbstractEntity {
    public function getId();
    public function setId($id);
    public function getIsbn();
    public function setIsbn($isbn);
    public function getTitle();
    public function setTitle($title);
    public function getDescription();
    public function setDescription($description);
    }
    

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50. class BookMapper extends AbstractMapper {
    public function addBook(BookEntity $book) {
    $this->bookRepository->save($book);
    $this->bookDetails->save($book);
    }
    }
    

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51. DUPLICATION?!
    Not Exactly
    

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52. We need to lower our database load, let’s cache.
    

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53. class BookService extends AbstractService {
    public function findRecent() {
    if ($this->cache->has('book.recent')) {
    return $this->cache->get('book.recent');
    }
    $results = $this->repository->findRecent();
    $this->cache->set('book.recent', $results);
    return $results;
    }
    }
    

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54. But that seems messy.
    

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55. DATA ACCESS OBJECTS
    • Or repositories in this case.
    • Allow us to target other
    areas to store data.
    • Allow for far better
    decoration
    • Things are looking up.
    

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56. class BookRepository extends AbstractRepository {
    public function save($book) {
    if (!$book->getId()) {
    return $this->insert('book', $book);
    }
    return $this->update('book', $book, array(
    'id' => $book->getId()
    ));
    }
    }
    

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57. interface RepositoryInterface {
    public function save($entity);
    public function find($id);
    public function findBy($criteria);
    public function findOneBy($criteria);
    public function delete($entity);
    }
    

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58. interface BookRepository {
    public function findRecent();
    }
    

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59. DECORATION
    

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60. DECORATOR PATTERN
    • Used to extend the
    functionality of a certain
    object.
    • Ultimately wrapping
    

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61. class BookDbRepository implements BookRepository {
    public function findRecent() {
    $book = $this->gateway->select(...);
    return $book;
    }
    }
    

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62. class BookCacheRepository implements BookRepository
    {
    public function findRecent() {
    if ($this->cache->has('book.recent')) {
    return $this->cache->get('book.recent');
    }
    $results = $this->delegateRepository-
    >findRecent();
    $this->cache->set('book.recent', $results);
    return $results;
    }
    }
    

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63. WHAT ARE WE ACHIEVING
    • Discoverability
    • Maintainability
    • Readability
    

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64. DEPENDENCY INJECTION
    Keeping everything alive.
    

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65. Dependency injection is the concept of simply
    injecting anything that is necessary for that object to
    operate.
    

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66. new BookService(
    new BookMapper(
    new BookCacheRepository(
    new BookDbRepository(
    new TableGateway('book')
    )
    )
    )
    );
    

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67. DI
    CONTAINERS
    • Inject dependencies by use
    of a container.
    

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68. return array(
    'di' => array(
    'BookService' => array(
    'arguments' => array(
    'BookMapper',
    ),
    ),
    'BookMapper' => array(
    'arguments' => array(
    'BookCacheRepository',
    ),
    ),
    'BookCacheRepository' => array(
    'arguments' => array(
    'BookDbRepository',
    ),
    ),
    'BookDbRepository' => array(
    'arguments' => array(
    'TableGateway',
    ),
    

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69. SO WHAT DOES THAT DO?
    • Creates an instance of
    TableGateway
    • Creates an instance of
    BookDbRepository
    • Then an instance of
    BookCacheRepository
    • Then an instance of BookMapper
    • Finally, an instance of BookService
    $bookService =
    $container->get(
    ‘BookService’
    );
    

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70. CLI?
    Oh, yes. We can!
    

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71. require 'bootstrap.php';
    $bookService = $container->get('book.service');
    $bookService->addBook($argv[0], $argv[1], $argv[2]);
    

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72. THAT’S SEEMS A
    LITTLE SLIMY…
    BUT, there is nothing
    preventing us from using
    controllers.
    

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73. if (php_sapi_name() == 'cli') {
    $router = $container->get('cliRouter');
    } else {
    $router = $container->get('router');
    }
    class BookCliController extends
    AbstractCliController {
    public function addBookAction();
    }
    

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74. BUT WHAT
    BELONGS?
    • Orchestration
    • Security
    • Transactions
    

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75. DOMAIN EVENTS
    A kitchen full of examples…
    

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76. class BookService extends AbstractService {
    public function addBook($isbn, $title,
    $description) {
    $book = new BookEntity();
    $book->setIsbn($isbn);
    $book->setTitle($title);
    $book->setDescription($description);
    $this->mapper->addBook($book);
    $this->trigger('book.add', array('book' =>
    $book));
    return $book;
    }
    }
    

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77. $bookService->attach('book.add', function($e) use
    ($mq) {
    $params = $e->getParams();
    $book = $params['book'];
    $mq->sendMessage('book.add', array('book' =>
    $book));
    });
    

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78. AUTHENTICATION
    Where does it belong?
    

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79. STACKING
    • Routing / Dispatch
    • Controllers
    • Services
    • Data Access Layer
    

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80. WEB SERVICES
    In general, practically free in most libraries, frameworks
    and languages.
    

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82. JEFF BEZOS MANDATE
    • All teams will henceforth expose their data and functionality through service interfaces.
    • Teams must communicate with each other through these interfaces.
    • There will be no other form of interprocess communication allowed: no direct linking, no direct reads of
    another team’s data store, no shared-memory model, no back-doors whatsoever. The only
    communication allowed is via service interface calls over the network.
    • It doesn’t matter what technology they use. HTTP, Corba, Pubsub, custom protocols — doesn’t matter.
    • All service interfaces, without exception, must be designed from the ground up to be externalizable.
    That is to say, the team must plan and design to be able to expose the interface to developers in the
    outside world. No exceptions.
    • Anyone who doesn’t do this will be fired.
    • Thank you; have a nice day!
    

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83. REST
    • HTTP with HTTP verbs
    • Involves collections of
    resources.
    

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84. $app->get('/api/book',
    'ApiBookController.recentAction');
    $app->put('/api/book',
    'ApiBookController.addAction');
    class ApiBookController extends RestfulController {
    public function recentAction() {
    return $this->bookService->findRecent();
    }
    public function addAction() {
    return $this->bookService->addBook(...);
    }
    }
    

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85. SOAP
    • XML Information Set
    • Operation under any
    transport protocol.
    

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86. $server = new Zend\Soap\Server(null, array(...));
    $server->setClass('BookService');
    $server->setObject(new BookService());
    $server->handle();
    

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87. RPC
    • Request / Response like
    protocol.
    • XML / JSON
    

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88. $server = new Zend\Json\Server\Server();
    $server->setClass('BookService');
    $server->handle();
    $server = new Zend\XmlRpc\Server();
    $server->setClass('BookService');
    echo $server->handle();
    

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89. DISCOVERY
    Strategies for discoverability
    

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90. BLUEPRINTS
    • API Blueprint
    • Apiary
    • ioDocs
    • Swagger
    

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91. HYPERMEDIA
    • HAL
    • JSON-LD
    • JSON Hyper Schema
    

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92. RECAP
    

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93. • http://pixabay.com/en/architecture-iron-steel-building-414035/
    • http://pixabay.com/en/home-demolition-destroyed-broken-557297/
    • http://pixabay.com/en/disassembly-component-parts-336507/
    • http://pixabay.com/en/taps-thread-drill-milling-444473/
    • http://pixabay.com/en/light-bulb-transparent-light-body-629661/
    • http://pixabay.com/en/church-trappist-georgia-monastery-233564/
    • http://pixabay.com/en/lego-site-build-replica-516557/
    • http://pixabay.com/en/water-tap-wall-outside-exterior-243046/
    • http://pixabay.com/en/question-mark-note-duplicate-457453/
    • http://pixabay.com/en/door-entry-stone-opening-grid-208081/
    • http://pixabay.com/en/onion-cut-fresh-tears-vegetable-161611/
    • http://pixabay.com/en/petronas-towers-skyscraper-433081/
    • http://pixabay.com/en/carbine-rope-hook-backup-climbing-7104/
    • http://pixabay.com/en/code-program-source-computer-pc-113611/
    • http://pixabay.com/en/kitchen-cabinets-countertop-granite-670247/
    • http://pixabay.com/en/injecting-medical-shot-veins-519389/
    • http://pixabay.com/en/books-shelf-retro-black-and-white-635341/
    • http://pixabay.com/en/crayons-pencils-blurred-circle-311062/
    • http://pixabay.com/en/soap-curd-soap-bathing-cleaning-390300/
    • http://pixabay.com/en/helicopter-model-model-helicopter-195660/
    • http://pixabay.com/en/bricks-roofing-house-building-420725/
    • http://pixabay.com/en/parrot-ara-zoo-bird-beautiful-bill-655777/
    • http://pixabay.com/en/gorilla-silverback-animal-448731/
    • http://pixabay.com/en/crash-demolition-site-home-floors-214744/
    • http://pixabay.com/en/beetle-beasts-field-insect-431125/
    • http://en.wikipedia.org/wiki/File:MVC-Process.svg
    • http://pixabay.com/en/prairie-dog-small-cute-rodent-keep-320836/
    • http://pixabay.com/en/key-lock-door-security-home-565607/
    • http://pixabay.com/en/library-inside-wood-book-books-428034/
    • http://pixabay.com/en/book-old-antique-pages-empty-pages-657637/
    • http://pixabay.com/en/dirt-mess-messy-grungy-face-576491/
    • http://pixabay.com/en/antique-box-collectible-electronic-21935/
    • http://pixabay.com/en/processor-cpu-board-circuits-540254/
    • http://pixabay.com/en/slug-shell-animals-wildlife-87037/
    • http://pixabay.com/en/colour-pencils-color-paint-draw-450623/
    • http://pixabay.com/en/mount-st-helens-volcanic-eruption-164848/
    • http://pixabay.com/en/baby-tears-small-child-sad-cry-443393/
    • http://pixabay.com/en/children-win-success-video-game-593313/
    • http://pixabay.com/en/peas-pod-pea-pod-green-fresh-580333/
    • http://pixabay.com/en/site-construction-work-support-592458/
    • http://pixabay.com/en/chimney-sweeper-chimney-sweep-14035/
    • https://pixabay.com/en/frog-relaxed-fig-funny-rest-914523/
    Image Credits
    THANK YOU!
    http://joind.in/talk/view/15635
    

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