JQuery Username Validation

问题

Does anyone have a working example of a username checker using jquery validation and jquery addmethod?

Something like this:

$("#register_form").validate({
    onkeyup:false,
    rules: {
        username: {
            required: true,
            minlength: 3,
            usernameCheck: true    // remote check for duplicate username
        },
});

jQuery.validator.addMethod("usernameCheck", function(username) {
    var isSuccess = false;
    $.ajax({
        url: "username_availability.php",
        data: "username=" + username,
        async: false,
        type: "POST",
        success:
        function(msg) {
            isSuccess = parseInt(msg);
        }
    });
    return isSuccess;
},"");

I've been looking all over Google for days, and I've noticed a number of threads like this that go unanswered or unsolved with a high view count. So if someone could provide a link or a solution, I'm sure a lot of JQuery noobs would benefit and be glad. :)

Hey guys, thanks a lot for all your help. I managed to find what I was looking for though.

The "milk example"? Really? It exists?

--Yes my son, it exists and it's awesome: http://jquery.bassistance.de/validate/demo/milk/

回答1:

I think your problem is that the the success method isn't being called by the time you return. You can change your code to be:

jQuery.validator.addMethod("usernameCheck", function(username) {
    var result = $.ajax({
        url: "username_availability.php",
        data: {username: username},
        async: false,
        type: "POST"
    }).responseText;
    return result === '1';
},"");

回答2:

Use the remote type instead of making up your own.

$("#register_form").validate({
    onkeyup:false,
    rules: {
        username: {
            required: true,
            minlength: 3,
            remote:'username_availability.php'
        },
});

It will pass a parameter of username=foo to your username_availability.php page. Return true or false from that page.

来源：https://stackoverflow.com/questions/5733253/jquery-username-validation