Merge branch 'feature/178' into develop

Close #178

Author: weierophinney

CHANGELOG.md

@@ -35,6 +35,11 @@ All notable changes to this project will be documented in this file, in reverse
   when representing the element; this change allows developers to override the
   format, which was the original intention.
 
+- [#178](https://github.com/zendframework/zend-form/pull/178) loosens the checks
+  in `Zend\Form\Element\DateTime::getValue()` to check against PHP's `DateTimeInterface` (vs
+  `DateTime`) when retrieving the value; this fixes edge cases where it was
+  instead returning the format for `DateTimeImmutable` values.
+
 ## 2.10.3 - TBD
 
 ### Added

src/Element/DateTime.php

@@ -66,9 +66,9 @@ public function setOptions($options)
     /**
      * Retrieve the element value
      *
-     * If the value is a DateTime object, and $returnFormattedValue is true
-     * (the default), we return the string
-     * representation using the currently registered format.
+     * If the value is instance of DateTimeInterface, and $returnFormattedValue
+     * is true (the default), we return the string representation using the
+     * currently registered format.
      *
      * If $returnFormattedValue is false, the original value will be
      * returned, regardless of type.
@@ -79,7 +79,7 @@ public function setOptions($options)
     public function getValue($returnFormattedValue = true)
     {
         $value = parent::getValue();
-        if (! $value instanceof PhpDateTime || ! $returnFormattedValue) {
+        if (! $value instanceof DateTimeInterface || ! $returnFormattedValue) {
             return $value;
         }
         $format = $this->getFormat();