Don't fetch the logged-in user to get their preferred language

Fixes #2473
Fixes mmikkel/CpFieldInspect-Craft#1

CHANGELOG-v3.md

@@ -4,6 +4,7 @@
 
 ### Added
 - Added the `getenv()` Twig function. ([#2471](https://github.com/craftcms/cms/pull/2471))
+- Added `craft\services\Users::getUserPreference()`.
 
 ### Changed
 - Element query classes can now specify the default `orderBy` value by overriding `craft\elements\db\ElementQuery::defaultOrderBy`.
@@ -16,6 +17,7 @@
 - Fixed a bug where `craft\helpers\ChartHelper::getRunChartDataFromQuery()` was overriding the query’s `SELECT` clause.
 - Fixed a bug where Single sections were showing the currently logged-in user as their author.
 - Fixed a bug where element queries for entries within Structure sections weren’t getting ordered in the Structure-defined order by default in some cases.
+- Fixed a bug where `yii\web\User::getIdentity()` would return `null` when called from a plugin’s `init()` method. ([#2473](https://github.com/craftcms/cms/issues/2473))
 
 ## 3.0.0-RC11 - 2018-02-20
 

src/base/ApplicationTrait.php

@@ -12,7 +12,6 @@
 use craft\db\Connection;
 use craft\db\MigrationManager;
 use craft\db\Query;
-use craft\elements\User;
 use craft\errors\DbConnectException;
 use craft\errors\WrongEditionException;
 use craft\events\EditionChangeEvent;
@@ -1186,15 +1185,13 @@ private function _getUserLanguage(): string
     {
         /** @var WebApplication|ConsoleApplication $this */
         // If the user is logged in *and* has a primary language set, use that
-        try {
-            /** @var User|null $user */
-            $user = $this->getUser()->getIdentity();
-        } catch (\Exception $e) {
-            $user = null;
-        }
-
-        if ($user && ($preferredLanguage = $user->getPreferredLanguage()) !== null) {
-            return $preferredLanguage;
+        if ($this instanceof WebApplication) {
+            // Don't actually try to fetch the user, as plugins haven't been loaded yet.
+            $session = $this->getSession();
+            $id = $session->getHasSessionId() || $session->getIsActive() ? $session->get($this->getUser()->idParam) : null;
+            if ($id && ($language = $this->getUsers()->getUserPreference($id, 'language')) !== null) {
+                return $language;
+            }
         }
 
         // Fall back on the default CP language, if there is one, otherwise the browser language

src/services/Users.php

@@ -272,6 +272,20 @@ public function saveUserPreferences(User $user, array $preferences)
             ->execute();
     }
 
+    /**
+     * Returns one of a user’s preferences by its key.
+     *
+     * @param int|null $userId The user’s ID
+     * @param string $key The preference’s key
+     * @param mixed $default The default value, if the preference hasn’t been set
+     * @return mixed The user’s preference
+     */
+    public function getUserPreference(int $userId = null, string $key, $default = null)
+    {
+        $preferences = $this->getUserPreferences($userId);
+        return $preferences[$key] ?? $default;
+    }
+
     /**
      * Sends a new account activation email for a user, regardless of their status.
      * A new verification code will generated for the user overwriting any existing one.