diff --git a/core/includes/form.inc b/core/includes/form.inc
index efbac995cd9690f8922b23e0bc2994168d87b42f..aaaeb1707afee05c1eadb256ce302efb82b193f4 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -257,6 +257,12 @@ function template_preprocess_details(&$variables) {
$variables['description'] = (!empty($element['#description'])) ? $element['#description'] : '';
$variables['children'] = (isset($element['#children'])) ? $element['#children'] : '';
$variables['value'] = (isset($element['#value'])) ? $element['#value'] : '';
+
+ // Display any error messages.
+ $variables['errors'] = NULL;
+ if (!empty($element['#errors']) && empty($element['#error_no_message'])) {
+ $variables['errors'] = $element['#errors'];
+ }
}
/**
diff --git a/core/modules/system/src/Tests/Form/ElementTest.php b/core/modules/system/src/Tests/Form/ElementTest.php
index 6555a4f063fbf592ffb069b2a6f572982b23e334..b7295ff49e19ef4faf17be5b7d630b5c6174f189 100644
--- a/core/modules/system/src/Tests/Form/ElementTest.php
+++ b/core/modules/system/src/Tests/Form/ElementTest.php
@@ -160,4 +160,12 @@ public function testFormAutocomplete() {
$this->assertEqual(count($result), 1, 'Ensure that the user does have access to the autocompletion');
}
+ /**
+ * Tests form element error messages.
+ */
+ public function testFormElementErrors() {
+ $this->drupalPostForm('form_test/details-form', [], 'Submit');
+ $this->assertText('I am an error on the details element.');
+ }
+
}
diff --git a/core/modules/system/templates/details.html.twig b/core/modules/system/templates/details.html.twig
index 1c0fd795eba1d35607d20b00ef25308221cb6aa4..cf50eb055e75588b92ec7f06823d366e0590395f 100644
--- a/core/modules/system/templates/details.html.twig
+++ b/core/modules/system/templates/details.html.twig
@@ -5,6 +5,7 @@
*
* Available variables
* - attributes: A list of HTML attributes for the details element.
+ * - errors: (optional) Any errors for this details element, may not be set.
* - title: (optional) The title of the element, may not be set.
* - description: (optional) The description of the element, may not be set.
* - children: (optional) The children of the element, may not be set.
@@ -20,6 +21,12 @@
{{ title }}
{%- endif -%}
+ {% if errors %}
+
+ {{ errors }}
+
+ {% endif %}
+
{{ description }}
{{ children }}
{{ value }}
diff --git a/core/modules/system/tests/modules/form_test/form_test.routing.yml b/core/modules/system/tests/modules/form_test/form_test.routing.yml
index e4804048f83929124326c3012cc6d54302f5a359..a37990bdc284085218f824392e4fe52188370b0d 100644
--- a/core/modules/system/tests/modules/form_test/form_test.routing.yml
+++ b/core/modules/system/tests/modules/form_test/form_test.routing.yml
@@ -402,6 +402,14 @@ form_test.button_class:
requirements:
_access: 'TRUE'
+form_test.details_form:
+ path: '/form_test/details-form'
+ defaults:
+ _form: '\Drupal\form_test\Form\FormTestDetailsForm'
+ _title: 'Form details form test'
+ requirements:
+ _access: 'TRUE'
+
form_test.description_display:
path: '/form_test/form-descriptions'
defaults:
diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
new file mode 100644
index 0000000000000000000000000000000000000000..8944a4cc18ff5116ec11918a5e3fb0915dca03ff
--- /dev/null
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
@@ -0,0 +1,51 @@
+ 'details',
+ '#title' => 'Details element',
+ '#open' => TRUE,
+ ];
+ $form['submit'] = ['#type' => 'submit', '#value' => 'Submit'];
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function validateForm(array &$form, FormStateInterface $form_state) {
+ $form_state->setErrorByName('meta', 'I am an error on the details element.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ }
+
+}
diff --git a/core/themes/classy/templates/form/details.html.twig b/core/themes/classy/templates/form/details.html.twig
index 9b149d77b29d0e4e1247825946f7e6ccd709c121..a4ce6f63dde0eaca216127dacca5a93de65d81a7 100644
--- a/core/themes/classy/templates/form/details.html.twig
+++ b/core/themes/classy/templates/form/details.html.twig
@@ -5,6 +5,7 @@
*
* Available variables
* - attributes: A list of HTML attributes for the details element.
+ * - errors: (optional) Any errors for this details element, may not be set.
* - title: (optional) The title of the element, may not be set.
* - description: (optional) The description of the element, may not be set.
* - children: (optional) The children of the element, may not be set.
@@ -18,6 +19,11 @@
{{ title }}
{%- endif -%}
+ {% if errors %}
+
+ {{ errors }}
+
+ {% endif %}
{%- if description -%}
{{ description }}
{%- endif -%}