From 7ea834bcd1fba95b85870402fd56b248940c096b Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Thu, 18 Aug 2022 15:42:26 +0900
Subject: [PATCH] feat: add validation_show_error() in Form helper

---
 system/Helpers/form_helper.php          | 26 +++++++++++++++++++++++++
 system/Validation/Validation.php        |  2 ++
 tests/system/Helpers/FormHelperTest.php | 10 ++++++++++
 3 files changed, 38 insertions(+)

diff --git a/system/Helpers/form_helper.php b/system/Helpers/form_helper.php
index fb74da239606..7a3d5370f6ce 100644
--- a/system/Helpers/form_helper.php
+++ b/system/Helpers/form_helper.php
@@ -732,6 +732,32 @@ function validation_list_errors(string $template = 'list'): string
     }
 }
 
+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
diff --git a/system/Validation/Validation.php b/system/Validation/Validation.php
index cd580812904a..312048c0037a 100644
--- a/system/Validation/Validation.php
+++ b/system/Validation/Validation.php
@@ -516,6 +516,8 @@ public function listErrors(string $template = 'list'): string
 
     /**
      * 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
     {
diff --git a/tests/system/Helpers/FormHelperTest.php b/tests/system/Helpers/FormHelperTest.php
index db67d58b56e6..fdeda5534963 100644
--- a/tests/system/Helpers/FormHelperTest.php
+++ b/tests/system/Helpers/FormHelperTest.php
@@ -953,6 +953,16 @@ public function testValidationListErrors()
         $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 ';