diff --git a/src/Umbrella/SimpleReport/Api/FieldDefinition.php b/src/Umbrella/SimpleReport/Api/FieldDefinition.php
index 3278cc5..94c204d 100755
--- a/src/Umbrella/SimpleReport/Api/FieldDefinition.php
+++ b/src/Umbrella/SimpleReport/Api/FieldDefinition.php
@@ -36,7 +36,7 @@ class FieldDefinition
     private $fieldCaption;
     private $callback;
 
-    function __construct($fieldName, $fieldCaption, $fieldType = FieldType::STRING, $callback = null, $fieldSize = null, $fieldWidth = null)
+    function __construct($fieldName, $fieldCaption, $fieldType = FieldType::STRING, $fieldSize = null, $fieldWidth = null, $callback = null)
     {
         $this->fieldName = $fieldName;
         $this->fieldType = $fieldType;
@@ -130,9 +130,10 @@ public function executeCallback($value)
     {
         $callback = $this->callback;
 
-        if (!is_callable($callback)) {
+        if (!$callback instanceof \Closure) {
             throw new \InvalidArgumentException('The callback must be a callable');
         }
+
         return $callback($value);
     }
 
diff --git a/src/Umbrella/SimpleReport/Api/FieldSet.php b/src/Umbrella/SimpleReport/Api/FieldSet.php
index 6a0e92a..b5f094b 100755
--- a/src/Umbrella/SimpleReport/Api/FieldSet.php
+++ b/src/Umbrella/SimpleReport/Api/FieldSet.php
@@ -32,9 +32,9 @@ function __construct()
         parent::__construct(array());
     }
 
-    public function addField($fieldName, $fieldCaption, $fieldType, $callback = null, $fieldSize = null, $fieldWidth = null)
+    public function addField($fieldName, $fieldCaption, $fieldType, $fieldSize = null, $fieldWidth = null, $callback = null)
     {
-        $fieldDefinition = new FieldDefinition($fieldName, $fieldCaption, $fieldType, $callback, $fieldSize, $fieldWidth);
+        $fieldDefinition = new FieldDefinition($fieldName, $fieldCaption, $fieldType, $fieldSize, $fieldWidth, $callback);
         $fieldDefinition->setFieldOrder($this->count());
         parent::append($fieldDefinition);
         return $this;
diff --git a/src/Umbrella/SimpleReport/BaseRenderer.php b/src/Umbrella/SimpleReport/BaseRenderer.php
index 40b716b..dace7c9 100755
--- a/src/Umbrella/SimpleReport/BaseRenderer.php
+++ b/src/Umbrella/SimpleReport/BaseRenderer.php
@@ -63,7 +63,7 @@ protected function getValue(IDatasource $datasource, FieldDefinition $fieldDescr
         $fieldTypeInstance = $this->configuration->getFieldTypeInstance($fieldTypeName, $rendererPrefix);
         $unformattedFieldValue = $datasource->getFieldValue($fieldDescription);
         $formattedFieldValue = $fieldTypeInstance->render($unformattedFieldValue);
-        if ($fieldDescription->getCallback()) {
+        if (null !== $fieldDescription->getCallback()) {
             $formattedFieldValue = $fieldDescription->executeCallBack($formattedFieldValue);
         }
         return $formattedFieldValue;
diff --git a/src/Umbrella/SimpleReport/Renderer/WkPdfRenderer.php b/src/Umbrella/SimpleReport/Renderer/WkPdfRenderer.php
index 247ea08..7e21670 100755
--- a/src/Umbrella/SimpleReport/Renderer/WkPdfRenderer.php
+++ b/src/Umbrella/SimpleReport/Renderer/WkPdfRenderer.php
@@ -292,10 +292,10 @@ protected function createAndFormatDate($format = 'd/m/Y')
     }
 
     /**
-     * Converte um HTML em PDF
+     * Converte um HTML em PDF. Esse método deve ser publico pois quando é feito o streaming ele precisa ser acessível.
      * @param string $htmlFile O conteúdo HTML para ser convertido
      */
-    protected function createPdf($htmlFile)
+    public function createPdf($htmlFile)
     {
         \wkhtmltox_convert('pdf', array(
             'out' => $this->output,
diff --git a/test/simpletablereport/SimpleWkPdfTest.php b/test/simpletablereport/SimpleWkPdfTest.php
index 40ea206..08f80c6 100755
--- a/test/simpletablereport/SimpleWkPdfTest.php
+++ b/test/simpletablereport/SimpleWkPdfTest.php
@@ -40,12 +40,12 @@ public function getData()
     {
         return array
             (
-            array('id' => 1, 'nome' => 'Kelson'),
-            array('id' => 2, 'nome' => 'KelsonCM'),
-            array('id' => 3, 'nome' => ''),
-            array('id' => 4, 'nome' => null),
-            array('id' => 5, 'nome' => 'null', 'nome2' => '#error'),
-            array('id' => 6, 'nome2' => '#error')
+            array('id' => 1, 'nome' => 'Kelson', 'data' => '2014-03-26'),
+            array('id' => 2, 'nome' => 'KelsonCM', 'data' => '2014-03-26'),
+            array('id' => 3, 'nome' => '', 'data' => '2014-03-26'),
+            array('id' => 4, 'nome' => null, 'data' => '2014-03-26'),
+            array('id' => 5, 'nome' => 'null', 'nome2' => '#error', 'data' => '2014-03-26'),
+            array('id' => 6, 'nome2' => '#error', 'data' => '2014-03-26')
         );
     }
 
@@ -55,11 +55,10 @@ public function getFieldset()
         return $fieldSet
                         ->addField('id', '#', FieldType::INTEGER)
                         ->addField('nome', 'Nome', FieldType::STRING)
-                        ->addField('razao', 'Razao', FieldType::FLOAT)
-                        ->addField('salario', 'Salario', FieldType::DECIMAL)
-                        ->addField('nascimento', 'Nascimento', FieldType::DATE)
-                        ->addField('almoco', 'Almoco', FieldType::TIME)
-                        ->addField('casamento', 'Casamento', FieldType::TIMESTAMP);
+                        ->addField('almoco', 'Almoco', FieldType::TIME, null, null, function($value) {
+                            $date = new DateTime($value);
+                            return $date->format('d-m-Y');
+                        });
     }
 
     /**
@@ -95,7 +94,7 @@ public function testFooter()
         $html = new \Umbrella\SimpleReport\Renderer\HtmlRenderer($datasource, $template);
         $renderer = new WkPdfRenderer($datasource, $template, $html);
         $renderer->setOutput('/tmp/teste-footer.pdf');
-        
+
         $renderer->setUseFooter(true)
                 ->setFooterPathTemplate('/var/www/simpletablereport/test/footer.html')
                 ->setFooterPath('/tmp/teste-footer')