Example of how to generate Atom feeds with E4X.

toAtom.js

/* the controller */
function blog() {

    function toAtom(results) {
        default xml namespace = "http://www.w3.org/2005/Atom";
        var feed = <feed/>;
        feed.id = "http://host.com/feeds/blog/atom";
        feed.title = "Sample Atom Feed";
        feed.author.name = "Jon Smith";
        feed.author.email = "jsmith@host.com";
        feed.entry = new XMLList();
        
        _.each(results.hits.hits, function(hit) {
            var entry = <entry/>;
            entry.id = hit._id;
            entry.title = hit._source.title;
            entry.content = hit._source.teaser;
            entry.published = hit._source.date;
            feed.entry += entry;
        });
        return feed.toString();
    }

    function search(query) {
        return evo.Request()
            .indicies("demos")
            .types("blogpost")
            .query(evo.QueryStringQuery(query))
            .doSearch(toAtom);
    }
    
    return {
        /* the action */
        atom: function(request) {
            var query = request.params.q || "*";
            return { 
                status: 200,
                headers: {"Content-Type": "text/xml"},
                body: search(query)
            };
        }
    };
}