add CallbackCollection class

src/Goodby/CSV/Export/Standard/Collection/CallbackCollection.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace Goodby\CSV\Export\Standard\Collection;
+
+use Iterator;
+
+class CallbackCollection implements Iterator
+{
+    private $callable;
+    private $data;
+
+    public function __construct($data, $callable)
+    {
+        $this->callable = $callable;
+
+        if (!is_callable($callable)) {
+            throw new \InvalidArgumentException('the second argument must be callable');
+        }
+
+        if (is_array($data)) {
+            $ao = new \ArrayObject($data);
+            $this->data = $ao->getIterator();
+        } elseif ($data instanceof Iterator) {
+            $this->data = $data;
+        } else {
+            throw new \InvalidArgumentException('data must be an array or a Iterator');
+        }
+    }
+
+    /**
+     * (PHP 5 &gt;= 5.0.0)<br/>
+     * Return the current element
+     * @link http://php.net/manual/en/iterator.current.php
+     * @return mixed Can return any type.
+     */
+    public function current()
+    {
+        return call_user_func($this->callable, $this->data->current());
+    }
+
+    /**
+     * (PHP 5 &gt;= 5.0.0)<br/>
+     * Move forward to next element
+     * @link http://php.net/manual/en/iterator.next.php
+     * @return void Any returned value is ignored.
+     */
+    public function next()
+    {
+        $this->data->next();
+    }
+
+    /**
+     * (PHP 5 &gt;= 5.0.0)<br/>
+     * Return the key of the current element
+     * @link http://php.net/manual/en/iterator.key.php
+     * @return mixed scalar on success, or null on failure.
+     */
+    public function key()
+    {
+        return $this->data->key();
+    }
+
+    /**
+     * (PHP 5 &gt;= 5.0.0)<br/>
+     * Checks if current position is valid
+     * @link http://php.net/manual/en/iterator.valid.php
+     * @return boolean The return value will be casted to boolean and then evaluated.
+     * Returns true on success or false on failure.
+     */
+    public function valid()
+    {
+        return $this->data->valid();
+    }
+
+    /**
+     * (PHP 5 &gt;= 5.0.0)<br/>
+     * Rewind the Iterator to the first element
+     * @link http://php.net/manual/en/iterator.rewind.php
+     * @return void Any returned value is ignored.
+     */
+    public function rewind()
+    {
+        $this->data->rewind();
+    }
+}

src/Goodby/CSV/Export/Tests/Standard/Join/Collection/PdoCollectionTest.php

@@ -5,6 +5,8 @@
 use Goodby\CSV\Export\Standard\Collection\PdoCollection;
 use Goodby\CSV\TestHelper\DbManager;
 
+use Goodby\CSV\Export\Standard\Collection\CallbackCollection;
+
 class PdoCollectionTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -44,4 +46,23 @@ public function testUsage()
             $this->assertEquals("name", $line["name"]);
         }
     }
+
+    public function testUsageWithCallbackCollection()
+    {
+        $pdo = $this->manager->getPdo();
+
+        $stmt = $pdo->prepare("SELECT * FROM collection_test");
+        $stmt->execute();
+
+        $pdoCollection = new PdoCollection($stmt);
+
+        $callbackCollection = new CallbackCollection($pdoCollection, function($row) {
+            $row['test'] = 'test';
+            return $row;
+        });
+
+        foreach ($callbackCollection as $line) {
+            $this->assertEquals('test', $line['test']);
+        }
+    }
 }

src/Goodby/CSV/Export/Tests/Standard/Unit/Collection/CallbackCollectionTest.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Goodby\CSV\Export\Tests\Standard\Unit\Collection;
+
+use Goodby\CSV\Export\Standard\Collection\CallbackCollection;
+
+class CallbackCollectionTest extends \PHPUnit_Framework_TestCase
+{
+	public function testSample()
+	{
+        $data = array();
+        $data[] = array('user', 'name1');
+        $data[] = array('user', 'name2');
+        $data[] = array('user', 'name3');
+
+        $collection = new CallbackCollection($data, function($mixed) {
+            return $mixed;
+        });
+
+        $index = 1;
+        foreach ($collection as $each) {
+            $this->assertEquals($each[0], 'user');
+            $this->assertEquals($each[1], 'name' . $index);
+            $index++;
+        }
+	}
+}