how to use the groovy controller element in JavaScript

I have

def exception = request.exception.stackTraceLines

in Groovy controller. How can I get the value of the exception in the JavaScript.

If you are adding exception to your return like this.

flash.message = message(exception: 'Error: xxx');

you can get it like this

<div class="message" role="status"> ${flash.message} </div>

just use ${ your flash.your_var_name}