Joomla: onContentAfterSave not triggered for articles - php

Question

I'm developing a Joomla plugin with onContentAfterSave event to send an email after saving a new articles.
the event are triggered when i save a new menu item or a new category.
but not for new article.
Joomla! 3.7.5
public function onContentAfterSave($context, $article, $isNew){
$link = JRoute::_(ContentHelperRoute::getArticleRoute( $article->id, $article->catid ));
$mailer = JFactory::getMailer();
$config = JFactory::getConfig();
$sender = array(
$config->get( 'mailfrom' ),
$config->get( 'fromname' )
);
$mailer->setSender($sender);
$user = JFactory::getUser();
$recipient = $user->email;
$recipient = array($recipient);
$mailer->addRecipient($recipient);
$body = '<p>Bonjour</p>'
.'Un nouveau article a été ajouté.';
$mailer->isHtml(true);
$mailer->Encoding = 'base64';
$mailer->setSubject('Nouveau article - BBN Times');
$mailer->setBody($body);
$send = $mailer->Send();
if ( $send !== true ) {
echo 'Error sending email: ';
} else {
echo 'Mail sent';
}
return true;
}

Answer 1

The onContentAfterSave is triggered by the Joomla core, and not by the extension's model, which means it should be triggered by any content saving.
I can think of 2 reasons why it is not triggered in your case:
You have a condition in your constructor checking for the extension type and only allowing certain extensions to use that event (or somewhere else in your plugin).
You have an error in the code above.