feat(Search): add subtree filter model

Closes #244

Author: Jens Schulze

src/Model/Product/Search/FilterSubtree.php

@@ -0,0 +1,68 @@
+<?php
+/**
+ * @author @jayS-de <[email protected]>
+ */
+
+namespace Commercetools\Core\Model\Product\Search;
+
+class FilterSubtree
+{
+    /**
+     * @var mixed
+     */
+    protected $id;
+
+    /**
+     * FilterRange constructor.
+     * @param mixed $id
+     */
+    public function __construct($id)
+    {
+        $this->id = $id;
+    }
+
+    /**
+     * @param $value
+     * @return string
+     */
+    protected function valueToString($value)
+    {
+        $value = (string)$value;
+        return '"' . (string)$value . '"';
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString()
+    {
+        return sprintf('subtree(%s)', $this->valueToString($this->getId()));
+    }
+
+    /**
+     * @param $id
+     * @return static
+     */
+    public static function ofId($id)
+    {
+        return new static($id);
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    /**
+     * @param mixed $id
+     * @return $this
+     */
+    public function setId($id)
+    {
+        $this->id = $id;
+        return $this;
+    }
+}

src/Model/Product/Search/FilterSubtreeCollection.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * @author @jayS-de <[email protected]>
+ */
+
+namespace Commercetools\Core\Model\Product\Search;
+
+use Commercetools\Core\Model\Common\Collection;
+
+/**
+ * @package Commercetools\Core\Model\Product\Search
+ *
+ * @method FilterSubtree current()
+ * @method FilterSubtreeCollection add(FilterSubtree $element)
+ * @method FilterSubtree getAt($offset)
+ */
+class FilterSubtreeCollection extends Collection
+{
+    protected $type = '\Commercetools\Core\Model\Product\Search\FilterSubtree';
+
+    public function __toString()
+    {
+        $values = [];
+        foreach ($this as $value) {
+            $values[] = (string)$value;
+        }
+        return implode(',', $values);
+    }
+}

tests/unit/Model/Product/Search/FilterSubtreeTest.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * @author @jayS-de <[email protected]>
+ */
+
+namespace Commercetools\Core\Model\Product\Search;
+
+class FilterSubtreeTest extends \PHPUnit_Framework_TestCase
+{
+    public function testMapValue()
+    {
+        $subtree = FilterSubtree::ofId('12345');
+        $this->assertSame('subtree("12345")', (string)$subtree);
+    }
+
+    public function testDefaultType()
+    {
+        $subtrees = FilterSubtreeCollection::of();
+        $subtrees
+            ->add(FilterSubtree::ofId('12345'))
+            ->add(FilterSubtree::ofId('abcde'))
+        ;
+        $this->assertSame('subtree("12345"),subtree("abcde")', (string)$subtrees);
+    }
+
+    public function testIntValue()
+    {
+        $subtree = FilterSubtree::ofId(12345);
+        $this->assertSame('subtree("12345")', (string)$subtree);
+    }
+}