I have local copy of Bootstrap which I minify along with other libraries using assetic but reading this solution, I would like to have Bootstrap loaded using CDN and IF the CDN is down only then return the local copy of Bootstrap (minified with other local libraries). How can I achieve this in Twig using Assetic? Current code:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
<title>{% block title %}Welcome!{% endblock %}</title>
{% block stylesheets %}
{% stylesheets filter="cssrewrite, scssphp" output="css/app.css"
"assets/vendor/bootstrap/dist/css/bootstrap.min.css"
"assets/vendor/components-font-awesome/css/font-awesome.min.css"
"assets/vendor/bootstrap-material-design/dist/css/bootstrap-material-design.css"
"assets/custom-assets/scss/background.scss"
%}
<link rel="stylesheet" href="{{ asset_url }}" />
{% endstylesheets %}
{% endblock %}
</head>
<body>
....
</body>
</html>