Here is a neat AJAX/Jquery Validation trick. Tell us what you think
With a default.aspx.cs web form with the code behind of:
Code:
using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Web.Services;
public partial class Recipe3 : System.Web.UI.Page
{
public static string[] UserNameArray;
protected void Page_Load(object sender, EventArgs e)
{
UserNameArray = new string[7] { "Imar Spanjaars", "Lori Lopez", "Leah Venegas", "Lisa Bartell", "Ruth Armandariz", "Frances Callan", "Monica Gildone" };
}
[WebMethod()]
public static bool CheckUserName(string sUserName)
{
foreach (string strUsername in UserNameArray){
if (sUserName == strUsername)
return true;
}
return false;
}
}
Then on the front end in the markup section you have:
Code:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Recipe3.aspx.cs" Inherits="Recipe3" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Chapter 6 - Recipe 3: Consuming page methods with AJAX</title>
<script src="js/jquery-1.4.1.js" type="text/javascript"></script>
<script language="javascript" type="text/javascript">
$(document).ready(function() {
$("#btnSubmit").click(function(e) {
e.preventDefault();
if ($("#txtUserName").val() == '')
alert("Please enter the UserName");
else
sendData($("#txtUserName").val());
});
function sendData(sUserName) {
var loc = window.location.href;
loc = (loc.substr(loc.length - 1, 1) == "/") ? loc + "Recipe3.aspx" : loc;
$.ajax({
type: "POST",
url: loc + "/CheckUserName",
data: '{"sUserName":"' + sUserName + '"}',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(msg) {
if (msg.d)
alert("The User Name is valid");
else
alert("The User Name is invalid")
},
error: function() {
alert("An unexpected error has occurred during processing.");
}
});
}
});
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
<asp:Button ID="btnSubmit" runat="server" Text="Check User Name" />
</div>
</form>
</body>
</html>
No mention of JSON in your book. Any consideration to using it later on maybe in newer texts for publishing maybe?
How about this neat little validation trick?
button below this post to show your appreciation!
