From c49f46f9e2500ff0944a603effe3050a4adade3b Mon Sep 17 00:00:00 2001
From: Marcel Werk <burntime@woltlab.com>
Date: Tue, 11 Apr 2023 11:09:08 +0200
Subject: [PATCH] Add example for `FormFieldValidator` usage (#369)
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Co-authored-by: Tim Düsterhus <duesterhus@woltlab.com>
---
 docs/php/api/form_builder/validation_data.md | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/docs/php/api/form_builder/validation_data.md b/docs/php/api/form_builder/validation_data.md
index 8956f2bc..ac4f2e84 100644
--- a/docs/php/api/form_builder/validation_data.md
+++ b/docs/php/api/form_builder/validation_data.md
@@ -38,6 +38,26 @@ Form field validation errors are added to form fields via the `IFormField::addVa
 
 Form field validators are added to form fields via the `addValidator(IFormFieldValidator $validator)` method.
 
+#### Example
+
+The following source code adds a validator that validates whether the value in the input field matches a specific value.
+
+```php
+$container->appendChildren([
+	FooField::create('a')
+		->addValidator(new FormFieldValidator('b', function (FooField $formField) {
+			if ($formField->getValue() != 'value') {
+				$formField->addValidationError(
+					new FormFieldValidationError(
+						'type',
+						'phrase'
+					)
+				);
+			}
+		})),
+	]);
+```
+
 
 ## Form Data
 
-- 
2.20.1