PHP7 Composite

Author: Dominik Liebler

Structural/Composite/Form.php

@@ -6,38 +6,38 @@
  * The composite node MUST extend the component contract. This is mandatory for building
  * a tree of components.
  */
-class Form extends FormElement
+class Form implements RenderableInterface
 {
     /**
-     * @var array|FormElement[]
+     * @var RenderableInterface[]
      */
-    protected $elements;
+    private $elements;
 
     /**
      * runs through all elements and calls render() on them, then returns the complete representation
      * of the form.
      *
      * from the outside, one will not see this and the form will act like a single object instance
      *
-     * @param int $indent
-     *
      * @return string
      */
-    public function render($indent = 0)
+    public function render(): string
     {
-        $formCode = '';
+        $formCode = '<form>';
 
         foreach ($this->elements as $element) {
-            $formCode .= $element->render($indent + 1).PHP_EOL;
+            $formCode .= $element->render();
         }
 
+        $formCode .= '</form>';
+
         return $formCode;
     }
 
     /**
-     * @param FormElement $element
+     * @param RenderableInterface $element
      */
-    public function addElement(FormElement $element)
+    public function addElement(RenderableInterface $element)
     {
         $this->elements[] = $element;
     }

Structural/Composite/FormElement.php

@@ -2,17 +2,10 @@
 
 namespace DesignPatterns\Structural\Composite;
 
-class InputElement extends FormElement
+class InputElement implements RenderableInterface
 {
-    /**
-     * renders the input element HTML.
-     *
-     * @param int $indent
-     *
-     * @return mixed|string
-     */
-    public function render($indent = 0)
+    public function render(): string
     {
-        return str_repeat('  ', $indent).'<input type="text" />';
+        return '<input type="text" />';
     }
 }

Structural/Composite/InputElement.php

@@ -28,9 +28,9 @@ Code
 
 You can also find these code on `GitHub`_
 
-FormElement.php
+RenderableInterface.php
 
-.. literalinclude:: FormElement.php
+.. literalinclude:: RenderableInterface.php
    :language: php
    :linenos:
 

Structural/Composite/README.rst

@@ -0,0 +1,8 @@
+<?php
+
+namespace DesignPatterns\Structural\Composite;
+
+interface RenderableInterface
+{
+    public function render(): string;
+}

Structural/Composite/RenderableInterface.php

@@ -4,32 +4,21 @@
 
 use DesignPatterns\Structural\Composite;
 
-/**
- * FormTest tests the composite pattern on Form.
- */
 class CompositeTest extends \PHPUnit_Framework_TestCase
 {
     public function testRender()
     {
         $form = new Composite\Form();
-        $form->addElement(new Composite\TextElement());
+        $form->addElement(new Composite\TextElement('Email:'));
         $form->addElement(new Composite\InputElement());
         $embed = new Composite\Form();
-        $embed->addElement(new Composite\TextElement());
+        $embed->addElement(new Composite\TextElement('Password:'));
         $embed->addElement(new Composite\InputElement());
-        $form->addElement($embed);  // here we have a embedded form (like SF2 does)
+        $form->addElement($embed);
 
-        $this->assertRegExp('#^\s{4}#m', $form->render());
-    }
-
-    /**
-     * The point of this pattern, a Composite must inherit from the node
-     * if you want to build trees.
-     */
-    public function testFormImplementsFormEelement()
-    {
-        $className = 'DesignPatterns\Structural\Composite\Form';
-        $abstractName = 'DesignPatterns\Structural\Composite\FormElement';
-        $this->assertTrue(is_subclass_of($className, $abstractName));
+        $this->assertEquals(
+            '<form>Email:<input type="text" /><form>Password:<input type="text" /></form></form>',
+            $form->render()
+        );
     }
 }

Structural/Composite/Tests/CompositeTest.php

@@ -2,17 +2,20 @@
 
 namespace DesignPatterns\Structural\Composite;
 
-class TextElement extends FormElement
+class TextElement implements RenderableInterface
 {
     /**
-     * renders the text element.
-     *
-     * @param int $indent
-     *
-     * @return mixed|string
+     * @var string
      */
-    public function render($indent = 0)
+    private $text;
+
+    public function __construct(string $text)
+    {
+        $this->text = $text;
+    }
+
+    public function render(): string
     {
-        return str_repeat('  ', $indent).'this is a text element';
+        return $this->text;
     }
 }