2.2. Bridge

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    PlainTextFormatter.php

    1. <?php
    2.  
    3. namespace DesignPatterns\Structural\Bridge;
    4.  
    5. class PlainTextFormatter implements FormatterInterface
    6. {
    7.     public function format(string $text)
    8.     {
    9.         return $text;
    10.     }
    11. }

    HtmlFormatter.php

    1. <?php
    2.  
    3. namespace DesignPatterns\Structural\Bridge;
    4.  
    5. {
    6.     /**
    7.      * @var FormatterInterface
    8.      */
    9.     protected $implementation;
    10.  
    11.     /**
    12.      * @param FormatterInterface $printer
    13.      */
    14.     public function __construct(FormatterInterface $printer)
    15.     {
    16.         $this->implementation = $printer;
    17.     }
    18.  
    19.     /**
    20.      * @param FormatterInterface $printer
    21.      */
    22.     public function setImplementation(FormatterInterface $printer)
    23.     {
    24.         $this->implementation = $printer;
    25.     }
    26.     abstract public function get();
    27. }

    HelloWorldService.php

    Tests/BridgeTest.php

    1. <?php
    2.  
    3. namespace DesignPatterns\Structural\Bridge\Tests;
    4.  
    5. use DesignPatterns\Structural\Bridge\HelloWorldService;
    6. use DesignPatterns\Structural\Bridge\HtmlFormatter;
    7. use DesignPatterns\Structural\Bridge\PlainTextFormatter;
    8. use PHPUnit\Framework\TestCase;
    9.  
    10. class BridgeTest extends TestCase
    11. {
    12.     public function testCanPrintUsingThePlainTextPrinter()
    13.     {
    14.         $service = new HelloWorldService(new PlainTextFormatter());
    15.         $this->assertEquals('Hello World', $service->get());
    16.  
    17.         // now change the implementation and use the HtmlFormatter instead
    18.         $service->setImplementation(new HtmlFormatter());
    19.         $this->assertEquals('<p>Hello World</p>', $service->get());
    20. }