jQuery AJAX error handling

ajax, jquery, php

Solution

The error return from the ajax call is returning the results from a page load that was not successful. It may be that your php page returns a valid page, but with results that are not what you want. This is handled withing the success return. Hopefully the following code snippit will help illustrate...

$.ajax({
    type: "POST",
    url: "login.php",
    data: "action=login&user=" + user + "&pass=" + pass,
    success: function(xhr){
        if ((xhr == "Invalid Login") 
                || (xhr == "Invalid charaters in username.") 
                || (xhr == "Missing username or password.")
                || (xhr == "Unknown Error")) {
            $("#loginMessageContent").html(xhr);
        }
        else {
            simplemodalClose (dialog);
        }
   }, 
   error: function(xhr) {
       alert ("Oopsie: " + xhr.statusText);
   }
});

Problem

I've searched the questions on here, but I don't have a good understanding of how to use the error handling in jQuery's AJAX (im a noob, so it just really doesn't make sense.) Can anybody describe this to a beginner? I'm currently posting information to a PHP script via AJAX, but want to allow jQuery to recognize if the returned data from the script is an error or success. Thanks! Dave

Original source