Dear Igor Domanov,
On your code you change:
$app = JFactory::getApplication();
$option = $app->input->get('option');
$view = $app->input->get('view');
if($option == 'com_templates' && $view == 'style')
$document->addScript(YT_PLUGIN_URL.'/includes/admin/js/yt-backendtemplate.js');
}
you missed '{' after 'if' statement
Please read the code following the user guide again:
$app = JFactory::getApplication();
$option = $app->input->get('option');
$view = $app->input->get('view');
if($option == 'com_templates' && $view == 'style'){
$document->addScript(YT_PLUGIN_URL.'/includes/admin/js/yt-backendtemplate.js');
}
Thanks