Added createDocument method to update query

library/Solarium/Document/ReadWrite.php

@@ -75,6 +75,7 @@ class Solarium_Document_ReadWrite extends Solarium_Document_ReadOnly
      * Constructor
      *
      * @param array $fields
+     * @param array $boosts
      */
     public function __construct($fields = array(), $boosts = array())
     {

library/Solarium/Query/Update.php

@@ -79,6 +79,7 @@ class Solarium_Query_Update extends Solarium_Query
     protected $_options = array(
         'handler'       => 'update',
         'resultclass'   => 'Solarium_Result_Update',
+        'documentclass' => 'Solarium_Document_ReadWrite',
     );
 
     /**
@@ -359,4 +360,47 @@ class Solarium_Query_Update extends Solarium_Query
        return $this->add(null, $optimize);
    }
 
+   /**
+    * Set a custom document class for use in the createDocument method
+    *
+    * This class should extend Solarium_Document_ReadWrite or
+    * at least be compatible with it's interface
+    *
+    * @param string $value classname
+    * @return Solarium_Query
+    */
+    public function setDocumentClass($value)
+    {
+        return $this->_setOption('documentclass', $value);
+    }
+
+    /**
+     * Get the current documentclass option
+     *
+     * The value is a classname, not an instance
+     *
+     * @return string
+     */
+    public function getDocumentClass()
+    {
+        return $this->getOption('documentclass');
+    }
+
+    /**
+     * Create a document object instance
+     *
+     * You can optionally directly supply the fields and boosts
+     * to get a ready-made document instance for direct use in an add command
+     *
+     * @param array $fields
+     * @param array $boosts
+     * @return Solarium_Document_ReadWrite
+     */
+    public function createDocument($fields = array(), $boosts = array())
+    {
+        $class = $this->getDocumentClass();
+
+        return new $class($fields, $boosts);
+    }
+
 }
\ No newline at end of file

tests/Solarium/Query/UpdateTest.php

@@ -402,4 +402,48 @@ class Solarium_Query_UpdateTest extends PHPUnit_Framework_TestCase
         $this->_query->createCommand('invalidtype');
     }
 
+    public function testSetAndGetDocumentClass()
+    {
+        $this->_query->setDocumentClass('MyDocument');
+        $this->assertEquals('MyDocument', $this->_query->getDocumentClass());
+    }
+
+    public function testCreateDocument()
+    {
+        $doc = $this->_query->createDocument();
+        $this->assertThat($doc, $this->isInstanceOf($this->_query->getDocumentClass()));
+    }
+
+    public function testCreateDocumentWithCustomClass()
+    {
+        $this->_query->setDocumentClass('MyCustomDoc');
+
+        $doc = $this->_query->createDocument();
+        $this->assertThat($doc, $this->isInstanceOf('MyCustomDoc'));
+    }
+
+    public function testCreateDocumentWithFieldsAndBoosts()
+    {
+        $fields = array('id' => 1, 'name' => 'testname');
+        $boosts = array('name' => 2.7);
+
+        $doc = $this->_query->createDocument($fields, $boosts);
+
+        $this->assertThat($doc, $this->isInstanceOf($this->_query->getDocumentClass()));
+
+        $this->assertEquals(
+            $fields,
+            $doc->getFields()
+        );
+
+        $this->assertEquals(
+            2.7,
+            $doc->getFieldBoost('name')
+        );
+    }
+
+}
+
+class MyCustomDoc extends Solarium_Document_ReadWrite{
+
 }