Best practices for passing data from asp.net-mvc to javascript

I sometimes pass data to my pages by writing a config object to the page via a JSON serializer:

var pageConfig = <%= ServerConfig.ToJson() %>;

Where you need to write the ToJson method yourself. This keeps the page state nicely contained, so that there is only one place where you inject server values. Everything from here on out is pure javascript. In your example, you could then do:

var isEditable = pageConfig.isEditable;

even in an external js file, if pageConfig is global. In that case, though, you should properly namespace it: MY_APP.pageConfig perhaps.