How can I force jQuery Validate to check for duplicate username in database?

Question

I\'m coming into the middle of this project so I\'m having to do a bit of re-writing because of sloppy code. I am using jQuery 1.6.1 and Validate 1.8.1.

First, here\

Answer 1

I faced the same problem, But I find the easiest solution just return true or false after encoding into json through php.

if ($users->username_exists())
{
    echo json_encode(FALSE);
}else{
    echo json_encode(TRUE);
}

Answer 2

On your server side script, try returning true or false instead of available and notavailable, as both of those strings are equivalent to true.

Answer 3

While you adding addMethod you should return true or false from server side.

and also that value have to be returned from addMethod.

ie something like this

$.validator.addMethod("checkAvailability",function(value,element){
    var parameter="action=checkusername&username="+username;
    $.ajax({
          url: "dbquery.php",
          type: "POST",
          async: false,
          data: parameter
          success:function(output)
                 {
                    return output
                 }
     });
},"Sorry, this user name is not available");

Answer 4

Check when the validation function is getting called, what the value of username is and what the value of output is: is it true or "true"?

I'm guessing latter: a string, so you could just do:

return output === "true" ? true : false; // I sincerely recommend using === here

Since if you return "false"; will evaluate to true because it's a non-empty string - yay dynamic langauges! :/

Example with remote:

$("#signup").validate( {
    rules: {
        username: {
            required: true,
            minlength: 5,
            remote: {
                url: "dbquery.php",
                type: "get",
                data: {
                    action: function () {
                        return "checkusername";
                    },
                    username: function() {
                        var username = $("#username").val();
                        return username;
                    }
                }
            }
        }
    },
    messages: {
        username: {
            required: "Enter a username"
        }
    },
    submitHandler: function(form) {
        form.submit();
    }
});

To set a custom error message your PHP file must return the message instead of false, so echo "Sorry, this user name is not available" in your PHP file.

Answer 5

My code:

$( "#myform" ).validate({
  rules: {
    EMAIL: {
      remote: {
        type: "post",  
        url: "checkMail.php",           
        data:{checkUsername:function(){return $("#EMAIL").val()}            
        }
      }
    }
  },messages:{EMAIL:{remote: "Already taken!"}}
});