1. In Yii2, an error occurs: Typed property common\\components\\i18n\\PhpMessageSource::$fallbackBasePath must not be accessed before initialization’. As shown in Figure 1
2. Provide a default value for $fallbackBasePath. Before modification: public ?string $fallbackBasePath; After modification: public ?string $fallbackBasePath = null;
PHP
<?php
namespace common\components\i18n;
class PhpMessageSource extends \yii\i18n\PhpMessageSource
{
public ?string $fallbackBasePath = null;
protected function loadMessages($category, $language)
{
$messages = parent::loadMessages($category, $language);
if (empty($messages) && $this->fallbackBasePath !== null) {
$fallback = new PhpMessageSource([
'basePath' => $this->fallbackBasePath,
'forceTranslation' => $this->forceTranslation,
'fileMap' => $this->fileMap,
]);
$messages = $fallback->loadMessages($category, $language);
}
return $messages;
}
protected function loadFallbackMessages($category, $fallbackLanguage, $messages, $originalMessageFile)
{
$fallbackMessageFile = $this->getMessageFilePath($category, $fallbackLanguage);
$fallbackMessages = $this->loadMessagesFromFile($fallbackMessageFile);
if (
$messages === null && $fallbackMessages === null
&& $fallbackLanguage !== $this->sourceLanguage
&& strpos($this->sourceLanguage, $fallbackLanguage) !== 0
) {
} elseif (empty($messages)) {
return $fallbackMessages;
} elseif (!empty($fallbackMessages)) {
foreach ($fallbackMessages as $key => $value) {
if (!empty($value) && empty($messages[$key])) {
$messages[$key] = $value;
}
}
}
return (array) $messages;
}
}
3. The error no longer occurs.