Use default flash element.

src/Controller/Component/FlashComponent.php

@@ -40,7 +40,7 @@ class FlashComponent extends Component {
  */
 	protected $_defaultConfig = [
 		'key' => 'flash',
-		'element' => null,
+		'element' => 'default',
 		'params' => []
 	];
 
@@ -63,7 +63,7 @@ class FlashComponent extends Component {
  * ### Options:
  *
  * - `key` The key to set under the session's Flash key
- * - `element` The element used to render the flash message
+ * - `element` The element used to render the flash message. Default to 'default'.
  * - `params` An array of variables to make available when using an element
  *
  * @param string|\Exception $message Message to be flashed. If an instance
@@ -80,14 +80,12 @@ class FlashComponent extends Component {
 			$message = $message->getMessage();
 		}
 
-		if ($opts['element'] !== null) {
-			list($plugin, $element) = pluginSplit($opts['element']);
+		list($plugin, $element) = pluginSplit($opts['element']);
 
-			if ($plugin) {
-				$opts['element'] = $plugin . '.Flash/' . $element;
-			} else {
-				$opts['element'] = 'Flash/' . $element;
-			}
+		if ($plugin) {
+			$opts['element'] = $plugin . '.Flash/' . $element;
+		} else {
+			$opts['element'] = 'Flash/' . $element;
 		}
 
 		$this->_session->write('Flash.' . $opts['key'], [

src/View/Helper/FlashHelper.php

@@ -62,18 +62,12 @@ class FlashHelper extends Helper {
  * @return string
  */
 	public function render($key = 'flash', array $options = []) {
-		$flash = $this->request->session()->read("Flash.$key");
-		$this->request->session()->delete("Flash.$key");
-
-		if (!$flash) {
+		if (!$this->request->session()->check("Flash.$key")) {
 			return '';
 		}
 
-		$flash = $options + $flash;
-
-		if ($flash['element'] === null) {
-			return $flash['message'];
-		}
+		$flash = $options + $this->request->session()->read("Flash.$key");
+		$this->request->session()->delete("Flash.$key");
 
 		return $this->_View->element($flash['element'], $flash);
 	}

tests/TestCase/Controller/Component/FlashComponentTest.php

@@ -65,7 +65,7 @@ class FlashComponentTest extends TestCase {
 		$expected = [
 			'message' => 'This is a test message',
 			'key' => 'flash',
-			'element' => null,
+			'element' => 'Flash/default',
 			'params' => []
 		];
 		$result = $this->Session->read('Flash.flash');
@@ -95,7 +95,7 @@ class FlashComponentTest extends TestCase {
 		$expected = [
 			'message' => 'This is a test message',
 			'key' => 'foobar',
-			'element' => null,
+			'element' => 'Flash/default',
 			'params' => []
 		];
 		$result = $this->Session->read('Flash.foobar');
@@ -115,7 +115,7 @@ class FlashComponentTest extends TestCase {
 		$expected = [
 			'message' => 'This is a test message',
 			'key' => 'flash',
-			'element' => null,
+			'element' => 'Flash/default',
 			'params' => ['code' => 404]
 		];
 		$result = $this->Session->read('Flash.flash');

tests/TestCase/View/Helper/FlashHelperTest.php

@@ -46,7 +46,7 @@ class FlashHelperTest extends TestCase {
 				'flash' => array(
 					'key' => 'flash',
 					'message' => 'This is a calling',
-					'element' => null,
+					'element' => 'Flash/default',
 					'params' => array()
 				),
 				'notification' => array(
@@ -75,7 +75,7 @@ class FlashHelperTest extends TestCase {
  */
 	public function tearDown() {
 		parent::tearDown();
-		unset($this->View, $this->Session);
+		unset($this->View, $this->Flash);
 	}
 
 /**
@@ -85,8 +85,8 @@ class FlashHelperTest extends TestCase {
  */
 	public function testFlash() {
 		$result = $this->Flash->render();
-		$expected = 'This is a calling';
-		$this->assertEquals($expected, $result);
+		$expected = '<div class="message">This is a calling</div>';
+		$this->assertContains($expected, $result);
 
 		$expected = '<div id="classy-message">Recorded</div>';
 		$result = $this->Flash->render('classy');

tests/test_app/TestApp/Template/Element/Flash/default.ctp

@@ -0,0 +1 @@
+<div class="message"><?= $message; ?></div>