Adding JS and CSS cleanly from included Twig templates

Question

I'm looking to find out if there's a clean way to add JS and CSS from included templates.

So, for example, if layout.html.twig has:

{% include 'GenericBundle:Generic:page.html.twig' with {'data': data} %}
...
{% block javascript %}

    {% javascripts
        '@GenericBundle/Resources/public/js/app/jquery/jquery.min.js'
        '@GenericBundle/Resources/public/js/lib/bootstrap/bootstrap.min.js'
    %}
        <script src="{{ asset_url }}"></script>
    {% endjavascripts %}

{% endblock %}

And in the generic bundle page I'd like to include some more Javascript but add it to the established Javascript block to keep to HTML and JS best practices.

Is there a clean way to do this? I'm using Symfony2, and could probably cludge together a solution using Singletons and such, but I'd rather a cleaner method if there's one available.

Solution

I know I'm a little late to the party, but with Twig 1.2, you can utilize the use tag and the block function:

GenericBundle:Generic:page.html.twig

{% block javascripts %}
    <script src="..."></script>
{% endblock %}
{% block included_content %}
   Bar
{% endblock %}

layout.html.twig

{% use 'GenericBundle:Generic:page.html.twig' with javascripts as page_javascripts %}

{% block javascript %}

    {% javascripts
        '@GenericBundle/Resources/public/js/app/jquery/jquery.min.js'
        '@GenericBundle/Resources/public/js/lib/bootstrap/bootstrap.min.js'
    %}
        <script src="{{ asset_url }}"></script>
    {% endjavascripts %}
    {{ block('page_javascript') }} // Don't forget the 'braces'

{% endblock %}

...
{{ block('included_content') }} // Don't forget the 'braces'

Comments

[Vincent Pazeller]

You must put quotes in {{ block('page_javascript') }} for this to work, otherwise you get a "Variable ... does not exists..." error message

[webDEVILopers]

{% include ... with { javascripts: block('javascripts') } %} worked fine for me.