Added support for getting custom message from Form validator

src/View/Form/FormContext.php

@@ -139,6 +139,27 @@ class FormContext implements ContextInterface
      */
     public function getRequiredMessage($field)
     {
+        $parts = explode('.', $field);
+
+        $validator = $this->_form->getValidator();
+        $fieldName = array_pop($parts);
+        if (!$validator->hasField($fieldName)) {
+            return null;
+        }
+
+        $ruleset = $validator->field($fieldName);
+
+
+        $requiredMessage = $validator->getRequiredMessage($fieldName);
+        $emptyMessage = $validator->getEmptyMessage($fieldName);
+
+        if ($ruleset->isPresenceRequired() && $requiredMessage) {
+            return $requiredMessage;
+        }
+        if (!$ruleset->isEmptyAllowed() && $emptyMessage) {
+            return $emptyMessage;
+        }
+
         return null;
     }
 

tests/TestCase/View/Form/FormContextTest.php

@@ -44,6 +44,27 @@ class FormContextTest extends TestCase
     }
 
     /**
+     * tests getRequiredMessage
+     *
+     * @return void
+     */
+    public function testGetRequiredMessage()
+    {
+        $validator = new Validator();
+        $validator->requirePresence('title', true, 'Don\'t forget a title!');
+
+        $form = new Form();
+        $form->setValidator(Form::DEFAULT_VALIDATOR, $validator);
+
+        $context = new FormContext($this->request, [
+            'entity' => $form,
+        ]);
+
+        $this->assertNull($context->getRequiredMessage('body'));
+        $this->assertSame('Don\'t forget a title!', $context->getRequiredMessage('title'));
+    }
+
+    /**
      * Test getting the primary key.
      *
      * @return void