ko.extenders.logOpt = function(target, option) {
    target.subscribe(function(newValue) {
       console.log(option + ": " + newValue);
    });
    return target;
};

this.firstName = ko.observable("Masoud").extend({logOpt: "my first name"});

my first name : Masoud

ko.extenders.negativeValueWarn = function (target, option) {
    target.hasWarning = ko.observable();

    function warn(newValue) {
        if(newValue && newValue.substring) {
            newValue = parseFloat(newValue);
        }
        target.hasWarning(newValue < 0 ? true : false);
    }

    warn(target());

    target.subscribe(warn);

    return target;
};

target(NewValue) => فراخوانی به صورت تابع و پاس دادن مقدار جدید به آن

target() => فراخوانی به صورت تابع بدون آرگومان

ko.extenders["booleanValue"] = function (target) {
    target.formattedValue = ko.computed({
        read: function () {
            if (target() === true) return "True";
            else if (target() === false) return "False";
        },
        write: function (newValue) {
            if (newValue) {
                if (newValue === "False") target(false);
                else if (newValue === "True") target(true);
            }
        }
    });

    target.formattedValue(target());
    return target;
};

<span>Do you want fries with that?</span>
<label>
  <input type="radio" name="question" value="True"
             data-bind="value: myValue.formattedValue" /> Yes
</label>
<label>
  <input type="radio" name="question" value="False"
             data-bind="value: myValue.formattedValue" /> No
</label>

 this.myValue= ko.observable(false).extend({ booleanValue: null });

<table id="std-grid">
      <thead>
           <th>نام</th>
           <th>نام خانوادگی</th>
           <th>سن</th>
     </thead>
     <tbody>
                
     </tbody>
</table>

<script>        
        $(document).ready(function() {
            $('#std-grid').dataTable({
                "aaData": [
                        ["پژمان", "پارسائی", "24"],
                        ["سعید", "الیاسی", "25"],
                        ["محمد رضا", "گلزار", "20"],
                        ["آرش", "ایرانی", "19"],
                        ["مرتضی", "فرمانی", "22"],
                        ["سعید", "حمیدیان", "23"],
                        ["امین", "پارسانیا", "23"],
                        ["محمد امین", "فقیهی", "24"],
                        ["محمد", "خرمی", "25"],
                        ["سینا", "امیریان", "20"],
                        ["آرش", "ایرانی", "19"],
                        ["وحید", "فرزانه", "22"],
                        ["امیر علی", "فرمانی", "23"],
                        ["امین", "حسینی", "23"],
            });
        });
        
    </script>

$(document).ready(function() {            
            $('#std-grid').dataTable({
                "aaData": [
                    {"FirstName" : "پژمان", "LastName" : "پارسائی", "Age" : "24"},
                    { "FirstName": "سعید", "LastName": "الیاسی", "Age": "25" },
                    { "FirstName": "محمد رضا", "LastName": "گلزار", "Age": "24" },
                    { "FirstName": "آرش", "LastName": "ایرانی", "Age": "24" },
                    { "FirstName": "مرتضی", "LastName": "فرمانی", "Age": "24" },
                    { "FirstName": "سعید", "LastName": "حمیدیان", "Age": "24" },
                    { "FirstName": "امین", "LastName": "پارسانیا", "Age": "24" },
                    { "FirstName": "محمد امین", "LastName": "فقیهی", "Age": "24" },
                    { "FirstName": "محمد", "LastName": "خرمی", "Age": "24" },
                    { "FirstName": "سینا", "LastName": "امیریان", "Age": "24" },
                    { "FirstName": "آرش", "LastName": "ایرانی", "Age": "24" },
                    { "FirstName": "وحید", "LastName": "فرزانه", "Age": "24" },
                    { "FirstName": "امیر علی", "LastName": "فرمانی", "Age": "24" },
                    { "FirstName": "امین", "LastName": "حسینی", "Age": "24" },
                ],
                "aoColumns": [
                      { "mDataProp": "FirstName" },
                      { "mDataProp": "LastName" },
                      { "mDataProp": "Age" }
                ]
            });
        });

$('#std-grid').dataTable({
          "bPaginate": false,
          "bLengthChange": false,
          "bFilter": false,
          "bSort": false,
          "bInfo": true,
          "bAutoWidth": false
});

$.ajax(), load(), $.get(), $.getJSON(), $.getScript(), and $.post()

using System;
using System.Globalization;
using System.Web.Script.Services;
using System.Web.Services;

namespace TestJQueryAjax
{
 [WebService(Namespace = "http://tempuri.org/")]
 [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
 [System.ComponentModel.ToolboxItem(false)]
 [ScriptService]
 public class AjaxSrv : WebService
 {
     public class TimeInfo
     {
         public string Date { set; get; }
         public string Hr { set; get; }
         public string Min { set; get; }
     }

     [WebMethod(EnableSession = true)]
     [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
     public TimeInfo GetTime()
     {
         DateTime now = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day);
         PersianCalendar pc = new PersianCalendar();
         string today = string.Format("{0}/{1}/{2}",
                                         pc.GetYear(now),
                                         pc.GetMonth(now).ToString("00"),
                                         pc.GetDayOfMonth(now).ToString("00"));
         TimeInfo ti = new TimeInfo
         {
             Date = today,
             Hr = DateTime.Now.Hour.ToString("00"),
             Min = DateTime.Now.Minute.ToString("00")
         };
         return ti;
     }
 }
}

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TestFillCtrls.aspx.cs"
 Inherits="TestJQueryAjax.TestFillCtrls" %>

<!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></title>

 <script src="js/jquery.js" type="text/javascript"></script>

 <script type="text/javascript">
     function validate() {
         $.ajax({
             type: "POST",
             url: 'AjaxSrv.asmx/GetTime',
             data: '{}',
             contentType: "application/json; charset=utf-8",
             dataType: "json",
             success:
                 function(msg) {                     
                     $("#<%=txtDate.ClientID %>").val(msg.d.Date);
                     $("#<%=txtHr.ClientID %>").val(msg.d.Hr);
                     $("#<%=txtMin.ClientID %>").val(msg.d.Min);
                 },
             error:
                 function(XMLHttpRequest, textStatus, errorThrown) {
                     alert("خطایی رخ داده است");
                 }
         });
         //debugger;
     } 
 </script>

</head>
<body>
 <form id="form1" runat="server">
 <div>
     <asp:TextBox ID="txtDate" runat="server" />
     <br />
     <asp:TextBox ID="txtHr" runat="server" />
     <br />
     <asp:TextBox ID="txtMin" runat="server" />
     <br />
     <asp:Button ID="btnGetTime" runat="server" Text="Click here!" UseSubmitBehavior="false"
             OnClientClick="validate();return false;" />
 </div>
 </form>
</body>
</html>

{"d":{"__type":"TestJQueryAjax.AjaxSrv+TimeInfo","Date":"1388/07/14","Hr":"12","Min":"59"}}

$.ajaxSetup({cache: false});

    <div class="k-rtl">
        <div id="report-grid"></div>
    </div>

using System;

namespace System.Web.Mvc
{
    public abstract class WebViewPage<TModel> : WebViewPage
    {
        protected WebViewPage();
        public AjaxHelper<TModel> Ajax { get; set; }
        public HtmlHelper<TModel> Html { get; set; }
        public TModel Model { get; }
        public ViewDataDictionary<TModel> ViewData { get; set; }
        public override void InitHelpers();
        protected override void SetViewData(ViewDataDictionary viewData);
    }
}

<head>
    <title>@ViewBag.Title</title>
    <link href="@Url.Content("~/Content/Site.css")" rel="stylesheet" type="text/css" />
    <script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script>    
</head>

namespace MvcApplication18.Models
{
    public class Employee
    {
        public int Id { set; get; }
        public string Name { set; get; }
    }
}

using System.Collections.Generic;

namespace MvcApplication18.Models
{
    public static class EmployeeDataSource
    {
        public static IList<Employee> CreateEmployees()
        {
            var list = new List<Employee>();
            for (int i = 0; i < 1000; i++)
            {
                list.Add(new Employee { Id = i + 1, Name = "name " + i });
            }
            return list;
        }
    }
}

using System.Linq;
using System.Web.Mvc;
using MvcApplication18.Models;

namespace MvcApplication18.Controllers
{
    public class HomeController : Controller
    {
        [HttpGet]
        public ActionResult Index()
        {
            return View();
        }

        [HttpPost] //for IE-8        
        public ActionResult EmployeeInfo(int? id)
        {
            if (!Request.IsAjaxRequest())
                return View("Error");

            if (!id.HasValue)
                return View("Error");

            var list = EmployeeDataSource.CreateEmployees();
            var data = list.Where(x => x.Id == id.Value).FirstOrDefault();
            if (data == null)
                return View("Error");

            return PartialView(viewName: "_EmployeeInfo", model: data);
        }
    }
}

@model MvcApplication18.Models.Employee

<strong>Name:</strong> @Model.Name

@{
    ViewBag.Title = "Index";
}
<h2>
    Index</h2>

<div id="EmployeeInfo">
    @Ajax.ActionLink(
     linkText: "Get Employee-1 info",
     actionName: "EmployeeInfo",
     controllerName: "Home",
     routeValues: new { id = 1 },
     ajaxOptions: new AjaxOptions
                  {
                      HttpMethod = "POST",
                      InsertionMode = InsertionMode.Replace,
                      UpdateTargetId = "EmployeeInfo",
                      LoadingElementId = "Progress"
                  })
</div>

<div id="Progress" style="display: none">
    <img src="@Url.Content("~/Content/images/loading.gif")" alt="loading..."  />
</div>

[AttributeUsage(AttributeTargets.Class|AttributeTargets.Method)]
public class AjaxOnlyAttribute : ActionFilterAttribute
{
  public override void OnActionExecuting(ActionExecutingContext filterContext)
  {
    if (filterContext.HttpContext.Request.IsAjaxRequest())
    {
      base.OnActionExecuting(filterContext);
    }
    else
    {
      throw new InvalidOperationException("This operation can only be accessed via Ajax requests");
    }
  }
}

[AjaxOnly]
public ActionResult SomeAjaxAction()
{
    return Content("Hello!");
}

<a data-ajax="true" data-ajax-loading="#Progress" data-ajax-method="POST" 
    data-ajax-mode="replace" data-ajax-update="#EmployeeInfo" 
    href="/Home/EmployeeInfo/1">Get Employee-1 info</a>

<a href="#" onclick="LoadEmployeeInfo()">Get Employee-1 info</a>
@section javascript
{
    <script type="text/javascript">
        function LoadEmployeeInfo() {
            showProgress();
            $.ajax({
                type: "POST",
                url: "/Home/EmployeeInfo",
                data: JSON.stringify({ id: 1 }),
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                // controller is returning a simple text, not json
                complete: function (xhr, status) {                    
                    var data = xhr.responseText;
                    if (status === 'error' || !data) {
                        //handleError                        
                    }
                    else {
                        $('#EmployeeInfo').html(data);
                    }
                    hideProgress();
                }
            });
        }
        function showProgress() {
            $('#Progress').css("display", "block");
        }
        function hideProgress() {
            $('#Progress').css("display", "none");
        }
    </script>
}

@RenderSection("javascript", required: false)

[HttpPost] //for IE-8        
public ActionResult EmployeeInfoData(int? id)
{
            if (!Request.IsAjaxRequest())
                return Json(false);

            if (!id.HasValue)
                return Json(false);

            var list = EmployeeDataSource.CreateEmployees();
            var data = list.Where(x => x.Id == id.Value).FirstOrDefault();
            if (data == null)
                return Json(false);

            return Json(data);
}

<a href="#" onclick="LoadEmployeeInfoData()">Get Employee-2 info</a>
@section javascript
{
    <script type="text/javascript">
        function LoadEmployeeInfoData() {
            showProgress();
            $.ajax({
                type: "POST",
                url: "/Home/EmployeeInfoData",
                data: JSON.stringify({ id: 1 }),
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                // controller is returning the json data
                success: function (result) {
                    if (result) {
                        alert(result.Id + ' - ' + result.Name);
                    }
                    hideProgress();
                },
                error: function (result) {
                    alert(result.status + ' ' + result.statusText);
                    hideProgress();
                }
            });
        }

        function showProgress() {
            $('#Progress').css("display", "block");
        }
        function hideProgress() {
            $('#Progress').css("display", "none");
        }
    </script>
}

[HttpPost] //for IE-8        
public ActionResult SearchEmployeeInfo(string data)
{
            if (!Request.IsAjaxRequest())
                return Content(string.Empty);

            if (string.IsNullOrWhiteSpace(data))
                return Content(string.Empty);

            var employeesList = EmployeeDataSource.CreateEmployees();
            var list = employeesList.Where(x => x.Name.Contains(data)).ToList();
            if (list == null || !list.Any())
                return Content(string.Empty);

            return PartialView(viewName: "_SearchEmployeeInfo", model: list);
}

@model IEnumerable<MvcApplication18.Models.Employee>

<table>
    <tr>
        <th>
            Name
        </th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Name)
        </td>
    </tr>
}

</table>

@using (Ajax.BeginForm(actionName: "SearchEmployeeInfo",
                       controllerName: "Home", 
                       ajaxOptions: new AjaxOptions
                                    {
                                         HttpMethod = "POST",
                                         InsertionMode = InsertionMode.Replace,
                                         UpdateTargetId = "EmployeeInfo",
                                         LoadingElementId = "Progress"
                                    }))
    {
      @Html.TextBox("data")
      <input type="submit" value="Search" />
    }

<form action="/Home/SearchEmployeeInfo" data-ajax="true" 
          data-ajax-loading="#Progress" data-ajax-method="POST" 
          data-ajax-mode="replace" data-ajax-update="#EmployeeInfo" 
          id="form0" method="post">
       <input id="data" name="data" type="text" value="" />
       <input type="submit" value="Search" />
</form>

$.validator.unobtrusive.parse("#{form-id}");

$.ajax
({
    url: "/{controller}/{action}/{id}",
    type: "get",
    success: function(data)
    {
        $.validator.unobtrusive.parse("#{form-id}");
    }
});

//or
$.get('/{controller}/{action}/{id}', function (data) { $.validator.unobtrusive.parse("#{form-id}"); });

@using (Ajax.BeginForm(
    "Action1",
    "Controller",
    null,
    new AjaxOptions { 
        OnSuccess = "onSuccess",
        UpdateTargetId = "result"
    },
    null)
)
{
    <input type="submit" value="Save" />
}

var onSuccess = function(result) {
    // enable unobtrusive validation for the contents
    // that was injected into the <div id="result"></div> node
    $.validator.unobtrusive.parse("#result");
};

SELECT 
    *, CONCAT(first_name, '', last_name) AS full_name
FROM
    Users;

ALTER TABLE Users
ADD COLUMN full_name TEXT GENERATED ALWAYS 
AS (CONCAT(first_name, ' ', last_name))

SELECT data ->> "$.description.shortDescription" FROM productMetadata
WHERE id = 1;

CREATE INDEX idx_json_data ON productMetadata (id);

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TestBrokenImages.aspx.cs"
   Inherits="testWebForms87.TestBrokenImages" %>

<!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>detecting broken images</title>

   <script src="jquery.min.js" type="text/javascript"></script>

   <script type="text/javascript">
       function errorReplace(arg) {
           //ارسال پیغام خطا
           $.ajax({
               type: "POST",
               url: "TestBrokenImages.aspx/GetErros",
               data: "{'image': '" + arg.src + "','page':'" + location.href + "'}",
               contentType: "application/json; charset=utf-8",
               dataType: "json"
           });
           //نمایش تصویری دلخواه بجای نمونه مفقود
           $(arg).attr('src', 'missing.png');           
       }

       //بررسی وضعیت تک تک تصاویر پس از بارگذاری کامل صفحه
       $(document).ready(function() {
           $(window).bind('load', function() {
               $('img').each(function() {
                   if (!this.complete || (!$.browser.msie && (typeof this.naturalWidth == "undefined" || this.naturalWidth == 0))) {
                       errorReplace(this);
                   }
               });
           })
       });
   </script>

</head>
<body>
   <form id="form1" runat="server">
   <div>
       <img src="img1.png" />
       <img src="img2.png" />
   </div>
   </form>
</body>
</html>

using System;
using System.IO;
using System.Web.Services;

namespace testWebForms87
{
   public partial class TestBrokenImages : System.Web.UI.Page
   {
       protected void Page_Load(object sender, EventArgs e)
       {
       }

       [WebMethod]
       public static void GetErros(string image,string page)
       {
           //ارسال ایمیل به مسؤول سایت و یا ذخیره خطاها در دیتابیس
       }
   }
}