sightly and javascript

I am just trying to create a angular mobile app using sightly.

In a geomatrix outdoors app example, controller java script is generated via controller.js.jsp using sling. (E.g. geometrixx-outdoors-app/components/angular/ng-image). The java script is dynamically prepared using jcr properties.

How to do this in sightly?

PS: I have gone through the sightly documentation site but couldn't get how to implement this.

No. Sightly (at least now) is only able to generate HTML. You could generate JS inside <script> tags in an HTML page, but you can't use Sightly to generate a standalone JS script. The same would be true for JSON, CSS, etc.

What would best practice be however? I assume best practice would be use a JSP or Ecma to generate a dynamic JS file. Sightly is defined as being an HTML templating system right, so if you aren't generating HTML shouldn't you be using a different templating language? 

@orotas - that's what I meant by "ugly" 

Generating JS (or CSS or JSON) with Sightly is possible, but because it uses HTML constructs, it looks weird. Although arguably the same thing could be said about JSP or ESP.