Add schema default checking for FormContext.

Closes #11267

src/View/Form/FormContext.php

@@ -94,7 +94,28 @@ class FormContext implements ContextInterface
             return $val;
         }
 
-        return $options['default'];
+        if ($options['default'] !== null || !$options['schemaDefault']) {
+            return $options['default'];
+        }
+
+        return $this->_schemaDefault($field);
+    }
+
+    /**
+     * Get default value from form schema for given field.
+     *
+     * @param string $field Field name.
+
+     * @return mixed
+     */
+    protected function _schemaDefault($field)
+    {
+        $field = $this->_form->schema()->field($field);
+        if ($field) {
+            return $field['default'];
+        }
+
+        return null;
     }
 
     /**

tests/TestCase/View/Form/FormContextTest.php

@@ -111,10 +111,24 @@ class FormContextTest extends TestCase
      */
     public function testValDefault()
     {
-        $context = new FormContext($this->request, ['entity' => new Form()]);
+        $form = new Form();
+        $form->schema()->addField('name', ['default' => 'schema default']);
+        $context = new FormContext($this->request, ['entity' => $form]);
+
+        $result = $context->val('title');
+        $this->assertNull($result);
 
         $result = $context->val('title', ['default' => 'default default']);
         $this->assertEquals('default default', $result);
+
+        $result = $context->val('name');
+        $this->assertEquals('schema default', $result);
+
+        $result = $context->val('name', ['default' => 'custom default']);
+        $this->assertEquals('custom default', $result);
+
+        $result = $context->val('name', ['schemaDefault' => false]);
+        $this->assertNull($result);
     }
 
     /**