ExtJs 6 - Getting the objects from the returned JSON through the success function

Question

I am using record.erase to delete a record, and I want to be able to display an error message if the backend is unable to delete the record for whatever reason. I want to be able to display the msg that is returned in the JSON. I assume I can do that through the operation parameter but haven't been able to find a way.

So how can I access the "success" and "msg" from the JSON?

Controller

if (record.data.privatePwdsCount === 0)
        Ext.Msg.confirm("Delete", "Are you sure you want to delete this group?", function (id, value) {
            if (id === 'yes') {           
                record.erase({
                    success: function (record, operation) {
                        // check if 'success' is true or false
                        // if true = do nothing
                        // if false = display error msg to user
                    }
                });                  
            }
        });
    else {
        Ext.Msg.alert("Cannot Delete Group", "This group has existing passwords, delete the passwords first to continue");
    }

JSON

"{"success":true,"msg":"Private Group 20 was deleted."}"

Answer 1

Figured it out myself, quite simple really -

var jsonResponse = Ext.decode(operation.getResponse().responseText);
var success = jsonResponse.success;
var msg = jsonResponse.msg;