Language condition rule

Resolves #15952

CHANGELOG-WIP.md

@@ -1,6 +1,7 @@
 # Release Notes for Craft CMS 4.13 (WIP)
 
 ### Administration
+- Added the “Language” element condition rule. ([#15952](https://github.com/craftcms/cms/discussions/15952))
 - Added `pc/*` commands as an alias of `project-config/*`.
 - Added the `--except`, `--minor-only`, and `--patch-only` options to the `update` command. ([#15829](https://github.com/craftcms/cms/pull/15829))
 

src/elements/conditions/ElementCondition.php

@@ -130,6 +130,7 @@ protected function conditionRuleTypes(): array
 
  if (Craft::$app->getIsMultiSite() && (!$elementType || $elementType::isLocalized())) {
  $types[] = SiteConditionRule::class;
+ $types[] = LanguageConditionRule::class;
 
  if (count(Craft::$app->getSites()->getAllGroups()) > 1) {
  $types[] = SiteGroupConditionRule::class;

src/elements/conditions/LanguageConditionRule.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace craft\elements\conditions;
+
+use Craft;
+use craft\base\conditions\BaseMultiSelectConditionRule;
+use craft\base\ElementInterface;
+use craft\elements\db\ElementQueryInterface;
+use craft\helpers\ArrayHelper;
+use craft\i18n\Locale;
+
+/**
+ * Site condition rule.
+ *
+ * @author Pixel & Tonic, Inc. <support@pixelandtonic.com>
+ * @since 4.13.0
+ */
+class LanguageConditionRule extends BaseMultiSelectConditionRule implements ElementConditionRuleInterface
+{
+ /**
+ * @inheritdoc
+ */
+ public function getLabel(): string
+ {
+ return Craft::t('app', 'Language');
+ }
+
+ /**
+ * @inheritdoc
+ */
+ public function getExclusiveQueryParams(): array
+ {
+ return ['site', 'siteId'];
+ }
+
+ /**
+ * @inheritdoc
+ */
+ protected function options(): array
+ {
+ return ArrayHelper::map(
+ Craft::$app->getI18n()->getSiteLocales(),
+ fn(Locale $locale) => $locale->id,
+ fn(Locale $locale) => $locale->getDisplayName(Craft::$app->language),
+ );
+ }
+
+ /**
+ * @inheritdoc
+ */
+ public function modifyQuery(ElementQueryInterface $query): void
+ {
+ $query->language($this->paramValue());
+ }
+
+ /**
+ * @inheritdoc
+ */
+ public function matchElement(ElementInterface $element): bool
+ {
+ return $this->matchValue($element->getLanguage());
+ }
+}