From 30231933c1785677bd0197350ee02f1d71486d5c Mon Sep 17 00:00:00 2001
From: Matthias Schmidt <gravatronics@live.com>
Date: Sat, 10 Feb 2018 20:32:37 +0100
Subject: [PATCH] Add possibility to require label for form fields

See #2509
---
 .../lib/system/form/builder/IFormElement.class.php     |  7 +++++++
 .../lib/system/form/builder/TFormElement.class.php     | 10 ++++++++++
 .../form/builder/field/AbstractFormField.class.php     |  4 ++++
 .../form/builder/field/BooleanFormField.class.php      |  7 +++++++
 4 files changed, 28 insertions(+)

diff --git a/wcfsetup/install/files/lib/system/form/builder/IFormElement.class.php b/wcfsetup/install/files/lib/system/form/builder/IFormElement.class.php
index 7d97f3bdef..9b84e4e654 100644
--- a/wcfsetup/install/files/lib/system/form/builder/IFormElement.class.php
+++ b/wcfsetup/install/files/lib/system/form/builder/IFormElement.class.php
@@ -51,4 +51,11 @@ interface IFormElement extends IFormNode {
 	 * @throws	\InvalidArgumentException	if the given label is invalid
 	 */
 	public function label(string $languageItem = null, array $variables = []): IFormElement;
+	
+	/**
+	 * Returns `true` if this element requires a label to be set.
+	 * 
+	 * @return	bool
+	 */
+	public function requiresLabel(): bool;
 }
diff --git a/wcfsetup/install/files/lib/system/form/builder/TFormElement.class.php b/wcfsetup/install/files/lib/system/form/builder/TFormElement.class.php
index 0b983835f7..9a099ff8b8 100644
--- a/wcfsetup/install/files/lib/system/form/builder/TFormElement.class.php
+++ b/wcfsetup/install/files/lib/system/form/builder/TFormElement.class.php
@@ -104,4 +104,14 @@ trait TFormElement {
 		
 		return $this;
 	}
+	
+	/**
+	 * Returns `true` if this element requires a label to be set.
+	 * 
+	 * @return	bool
+	 */
+	public function requiresLabel(): bool {
+		// by default, form elements do not require a label 
+		return false;
+	}
 }
diff --git a/wcfsetup/install/files/lib/system/form/builder/field/AbstractFormField.class.php b/wcfsetup/install/files/lib/system/form/builder/field/AbstractFormField.class.php
index 0aaedbdd2b..b652d2c100 100644
--- a/wcfsetup/install/files/lib/system/form/builder/field/AbstractFormField.class.php
+++ b/wcfsetup/install/files/lib/system/form/builder/field/AbstractFormField.class.php
@@ -107,6 +107,10 @@ abstract class AbstractFormField implements IFormField {
 			throw new \LogicException("\$templateName property has not been set.");
 		}
 		
+		if ($this->requiresLabel() && $this->getLabel() === null) {
+			throw new \UnexpectedValueException("Form field '{$this->getPrefixedId()}' requires a label.");
+		}
+		
 		return WCF::getTPL()->fetch(
 			$this->templateName,
 			'wcf',
diff --git a/wcfsetup/install/files/lib/system/form/builder/field/BooleanFormField.class.php b/wcfsetup/install/files/lib/system/form/builder/field/BooleanFormField.class.php
index a244a9454f..3addaf84ad 100644
--- a/wcfsetup/install/files/lib/system/form/builder/field/BooleanFormField.class.php
+++ b/wcfsetup/install/files/lib/system/form/builder/field/BooleanFormField.class.php
@@ -36,6 +36,13 @@ class BooleanFormField extends AbstractFormField {
 		return $this;
 	}
 	
+	/**
+	 * @inheritDoc
+	 */
+	public function requiresLabel(): bool {
+		return true;
+	}
+	
 	/**
 	 * @inheritDoc
 	 */
-- 
2.20.1