feat: add validation_show_error() in Form helper

system/Helpers/form_helper.php

@@ -732,6 +732,32 @@ if (! function_exists('validation_list_errors')) {
     }
 }
 
+if (! function_exists('validation_show_error')) {
+    /**
+     * Displays a single error in formatted HTML.
+     *
+     * See Validation::showError()
+     */
+    function validation_show_error(string $field, string $template = 'single'): string
+    {
+        $config = config('Validation');
+        $view   = Services::renderer();
+
+        $errors = validation_errors();
+
+        if (! array_key_exists($field, $errors)) {
+            return '';
+        }
+
+        if (! array_key_exists($template, $config->templates)) {
+            throw ValidationException::forInvalidTemplate($template);
+        }
+
+        return $view->setVar('error', $errors[$field])
+            ->render($config->templates[$template]);
+    }
+}
+
 if (! function_exists('parse_form_attributes')) {
     /**
      * Parse the form attributes

system/Validation/Validation.php

@@ -516,6 +516,8 @@ class Validation implements ValidationInterface
 
     /**
      * Displays a single error in formatted HTML as defined in the $template view.
+     *
+     * You can also use validation_show_error() in Form helper.
      */
     public function showError(string $field, string $template = 'single'): string
     {

tests/system/Helpers/FormHelperTest.php

@@ -953,6 +953,16 @@ final class FormHelperTest extends CIUnitTestCase
         $this->assertStringContainsString('<li>The ID field is required.</li>', $html);
     }
 
+    public function testValidationShowError()
+    {
+        $validation = Services::validation();
+        $validation->setRule('id', 'ID', 'required')->run([]);
+
+        $html = validation_show_error('id');
+
+        $this->assertSame('<span class="help-block">The ID field is required.</span>' . "\n", $html);
+    }
+
     public function testFormParseFormAttributesTrue()
     {
         $expected = 'readonly ';