how to use the groovy controller element in JavaScript - grails

Question

I have
def exception = request.exception.stackTraceLines
in Groovy controller. How can I get the value of the exception in the JavaScript.

Answer 1

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}

Answer 2

You have multiple options to fix this. When using javascript I usually use a wrapper which can hold the error message/stacktrace. It depends on where and how you want to do the error handling. Example:
def book = new Book(params)
book.validate()
render (contentType: "text/json") {[
"data": book,
"errors": book.hasErrors() ? book.errors : null
]}
Then you can check if "errors" has a value when getting back your JSON to determine if there are errors in the input for instance. (Elvis operator probably works too, book.errors ?: null) Other (uncatched) exceptions I handle in the error callback I usually define in my JavaScript. (jQuery mostly, (with malsup jquery.form.js in this case))
$(function() {
$("form").live("submit", function() {
$(this).ajaxSubmit({
error: function (msg) {
/* Catch hard errors here (500's) */
alert("Error occurred: " + msg);
},
success: function(wrapper) {
if (wrapper.errors != null) {
/* Handle model errors here */
} else {
/* Parse data here */
var book = wrapper.data;
}
}
});
return false;
});

Answer 3

You can also do this
render(template:"book",model:[book:theBook, exception:exception])
Or like this (didnt try, don't know if works)
render(template:"book",model:[book:theBook, exception:exception!=null?exception:""])
and then access from the GSP like this
${exception.getMessage()}