Sitemesh layout applied to AJAX response (gotcha)

Grails supports multiple ways to specify a sitemesh layout for your responses. One way I wasn't familiar with is by convention, i.e. if you have a controller 'BookController' and a layout in /views/layouts called book.gsp all the actions in BookController will be rendered with the book layout by default - even if you do render("some text") or render(template: "/sometemplate").

So if you're wondering why all your AJAX responses are getting wrapped up in a sitemesh template this could be the reason. You can stop this by changing the content type to text/plain or by renaming the layout and specifying it explicitly in your gsps using <meta name="layout" content="layoutname"/>.