In ASP.NET with JQuery, how would you define and handle exceptional conditions

I use $.ajax to call a .asmx to get JSON data back. The server side process 开发者_运维知识库will meet some exceptional conditions which will give back to client error response for displaying error message.

How would you design the error hanlding mechanism? I mean what would you make server side retrun and let client handle the error?

Thanks.

If it's just an error message (a string), then you can just return that string and set the status to 500 so jQuery recognizes it's not a successful request. Then just use your error handler (or a global .ajaxError() handler for all requests) to do what you want with that message.

For example a simple way to handle all errors like this (instead of per-$.ajax() call) would be:

$(document).ajaxError(function(e, xhr) {
  alert("There was an error, server responded with: " + xhr.responseText);
});

ther's an error handler in jquery just like the success function, you need to handle it:

function CallWebService(ParentPage) {
    $.ajax({
        type: "POST",
        url: "../Admission/AdmissionService.asmx/LoadLocations",
        data: "{'ParentPage':'" + ParentPage + "'}",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (data) {
            $('.innerHospitalCensusdiv').html(data.d);
            BindSelectLocation();
        },**error: function(ex){
            //handle error here
        }**
    });
}