[6.0] Fix language autoload in CMSPlugin constructor to work safely (#40355)

* Move language autoload out from CMSPlugin constructor

* CMSPlugin::autoloadLanguage()

* cs

* re-arrange autoloadLanguage feature

Author: Fedik

libraries/src/Plugin/CMSPlugin.php

@@ -72,13 +72,25 @@ abstract class CMSPlugin implements DispatcherAwareInterface, PluginInterface, L
     protected $_type = null;
 
     /**
-     * Affects constructor behavior. If true, language files will be loaded automatically.
+     * If true, language files of the plugin will be loaded automatically.
+     *
+     * NOTE: Enabling this feature have a negative effect on performance,
+     * therefore it is recommended to load a language manually, in the respective event.
      *
      * @var    boolean
      * @since  3.1
      */
     protected $autoloadLanguage = false;
 
+    /**
+     * Internal flag for autoloadLanguage feature.
+     *
+     * @var   boolean
+     *
+     * @since   __DEPLOY_VERSION__
+     */
+    private $autoloadLanguageDone = false;
+
     /**
      * Should I try to detect and register legacy event listeners, i.e. methods which accept unwrapped arguments? While
      * this maintains a great degree of backwards compatibility to Joomla! 3.x-style plugins it is much slower. You are
@@ -154,11 +166,6 @@ public function __construct($config = [])
             $this->_type = $config['type'];
         }
 
-        // Load the language files if needed.
-        if ($this->autoloadLanguage) {
-            $this->loadLanguage();
-        }
-
         if (property_exists($this, 'app')) {
             @trigger_error('The application should be injected through setApplication() and requested through getApplication().', E_USER_DEPRECATED);
             $reflection  = new \ReflectionClass($this);
@@ -178,6 +185,12 @@ public function __construct($config = [])
                 $this->db = Factory::getDbo();
             }
         }
+
+        // Load the language files if needed.
+        // It is required Application to be set, so we trying it here and in CMSPlugin::setApplication()
+        if ($this->autoloadLanguage && $this->getApplication()) {
+            $this->autoloadLanguage();
+        }
     }
 
     /**
@@ -193,11 +206,26 @@ public function __construct($config = [])
     public function loadLanguage($extension = '', $basePath = JPATH_ADMINISTRATOR)
     {
         if (empty($extension)) {
-            $extension = 'Plg_' . $this->_type . '_' . $this->_name;
+            $extension = 'plg_' . $this->_type . '_' . $this->_name;
         }
 
         $extension = strtolower($extension);
-        $lang      = $this->getApplication() ? $this->getApplication()->getLanguage() : Factory::getLanguage();
+        $app       = $this->getApplication() ?: Factory::getApplication();
+        $lang      = $app->getLanguage();
+
+        if (!$lang) {
+            // @TODO: Throw an exception in Joomla 7
+            @trigger_error(
+                \sprintf(
+                    'Trying to load language before Application is initialised is discouraged. This will throw an exception in 7.0. Plugin "%s/%s"',
+                    $this->_type,
+                    $this->_name
+                ),
+                E_USER_DEPRECATED
+            );
+
+            return false;
+        }
 
         // If language already loaded, don't load it again.
         if ($lang->getPaths($extension)) {
@@ -208,6 +236,35 @@ public function loadLanguage($extension = '', $basePath = JPATH_ADMINISTRATOR)
             || $lang->load($extension, JPATH_PLUGINS . '/' . $this->_type . '/' . $this->_name);
     }
 
+    /**
+     * Method to handle language autoload feature in safe way, only when the language is initialised.
+     *
+     * @return void
+     *
+     * @internal  The method does not expect to be called outside the CMSPlugin class.
+     *
+     * @since   __DEPLOY_VERSION__
+     */
+    final protected function autoloadLanguage(): void
+    {
+        if ($this->autoloadLanguageDone) {
+            return;
+        }
+
+        $app = $this->getApplication();
+
+        // Check whether language already initialised in the Application, otherwise wait for it
+        if (!$app->getLanguage()) {
+            $app->getDispatcher()->addListener('onAfterInitialise', function () {
+                $this->loadLanguage();
+            });
+        } else {
+            $this->loadLanguage();
+        }
+
+        $this->autoloadLanguageDone = true;
+    }
+
     /**
      * Registers legacy Listeners to the Dispatcher, emulating how plugins worked under Joomla! 3.x and below.
      *
@@ -426,6 +483,11 @@ public function setApplication(CMSApplicationInterface $application): void
         if ($application->getLanguage()) {
             $this->setLanguage($application->getLanguage());
         }
+
+        // Try to load the language files if it were not loaded in the constructor already.
+        if ($this->autoloadLanguage) {
+            $this->autoloadLanguage();
+        }
     }
 
     /**

tests/Unit/Plugin/EditorsXtd/PageBreak/Extension/PageBreakTest.php

@@ -89,6 +89,7 @@ public function testInvalidPermissions()
         $user->method('getAuthorisedCategories')->willReturn([]);
 
         $app = $this->createStub(CMSWebApplicationInterface::class);
+        $app->method('getLanguage')->willReturn($this->createStub(Language::class));
         $app->method('getIdentity')->willReturn($user);
 
         $btnsReg = new ButtonsRegistry();
@@ -126,7 +127,9 @@ public function testInvalidApplication()
 
         $dispatcher = new Dispatcher();
         $plugin     = new PageBreak($dispatcher, ['name' => 'pagebreak', 'type' => 'editors-xtd', 'params' => []]);
-        $plugin->setApplication($this->createStub(CMSApplicationInterface::class));
+        $app        = $this->createStub(CMSApplicationInterface::class);
+        $app->method('getLanguage')->willReturn($this->createStub(Language::class));
+        $plugin->setApplication($app);
         $plugin->onEditorButtonsSetup($event);
 
         $button = $btnsReg->getAll()[0] ?? false;

tests/Unit/Plugin/Filesystem/Local/Extension/LocalPluginTest.php

@@ -106,6 +106,7 @@ public function testAdapters()
 
         $app = $this->createStub(CMSApplicationInterface::class);
         $app->method('getIdentity')->willReturn(new User());
+        $app->method('getLanguage')->willReturn($this->createStub(Language::class));
 
         $plugin   = new Local($dispatcher, ['params' => ['directories' => '[{"directory": "tests"}]']], JPATH_ROOT);
         $plugin->setApplication($app);