JSONP (JavaScript Object Notation with padding):
The difference
between JSONP and JSON is that, JSONP will wrap the JSON data as a function
call, while the function name is passed in from the request URL.
In JavaScript all
ajax requests due to cross domain policy
or security model which prevents the
XMLHttpRequest object requesting resources on a different domain or port to the current page (there are sollutions
to get around this but they such as the Access-Control-Allow-Origin header but
not all browsers support them).
There are few solutions
Local proxy: Can't run a serverless
client
Flash:Remote host needs to deploy a crossdomain.xml file
Script tag: Difficult to know when the content is available, no standard
methodology, security risk".
JSONP is JSON with an
additional JavaScript callback function wrapping the JSON content.
JSON
with padding" - was created to allow you to request JSON resources from a
different domain.
- No XMLHTTPRequest object is used (no ajax)
- No Same-origin policies limitations
- No need for cross-domain policy files on servers
Interface :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.ServiceModel.Web;
using System.IO;
using System.ServiceModel.Activation;
[DataContract]
public class Funds
{
[DataMember(Name = "MainCategory",
Order = 1)]
public string
CategoryMain;
[DataMember(Name = "FundID",
Order = 2)]
public int ID;
[DataMember(Name = "FundCode",
Order = 3)]
public string Code;
[DataMember(Name = "FundName",
Order = 4)]
public string
WebFundName;
}
[ServiceContract]
public interface ITestJsonp
{
[OperationContract]
[WebGet(UriTemplate = "Fund/{fid}",
ResponseFormat = WebMessageFormat.Json)]
List<Funds>
getFundInfo(string fid);
}
Service :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.ServiceModel.Web;
using System.IO;
using System.ServiceModel.Activation;
[AspNetCompatibilityRequirements(RequirementsMode =
AspNetCompatibilityRequirementsMode.Allowed)]
public class TestJsonp : ITestJsonp
{
List<Funds>
_objfundList = new List<Funds>();
List<Funds>
_objfundListReturn = new List<Funds>();
Funds _objfunds;
public List<Funds> getFundInfo(string
fid)
{
FillData();
_objfunds = _objfundList.Find(delegate(Funds f) { return
f.ID == Convert.ToInt32(fid); });
_objfundListReturn.Add(_objfunds);
return _objfundListReturn;
}
public void
FillData()
{
for (int i = 1; i
<= 5; i++)
{
_objfunds = new Funds();
_objfunds.ID = i;
_objfunds.Code = "FuncCode -"
+ i;
_objfunds.WebFundName = "FundName
-" + i;
_objfunds.CategoryMain = "Category -
" + i;
_objfundList.Add(_objfunds);
}
}
}
Service Test:
Client Page :
<%@ Page
Language="C#"
AutoEventWireup="true"
CodeBehind="JSONP.aspx.cs"
Inherits="WcfService1.JSONP"
%>
<!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="Scripts/jquery-1.8.3.min.js"
type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function () {
var fid = getUrlVars()["fid"];
var URL = '';
if (fid == undefined) {
URL = "TestJsonp.svc/Fund/1?callback=?";
}
else {
URL = "TestJsonp.svc/Fund/"
+ fid + "?callback=?";
}
//**************Call 1**********************//
// JSONP CALL TO WCF SERVICE
$.ajax({
cache: false,
url: URL,
data: "{}",
type: "GET",
jsonpCallback: "parseresonse",
contentType: "application/javascript",
dataType: "jsonp",
error: function () {
alert("list failed!");
},
success: function (list) {
successCallback(list);
}
});
function successCallback(data) {
$.each(data.getFundInfoResult, function
(index, output) {
alert("Call-1 : " +
output.FundCode);
});
}
//************************************************//
//**************Call 2**********************//
$.getJSON(URL, displayImages);
function displayImages(data) {
$.each(data.getFundInfoResult, function
(index, output) {
alert("Call-2 : " +
output.FundName);
});
}
//**************Working**********************//
});
function getUrlVars() {
var vars = [], hash;
var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
for (var
i = 0; i < hashes.length; i++) {
hash = hashes[i].split('=');
vars.push(hash[0]);
vars[hash[0]] = hash[1];
}
return vars;
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
OutPut
can u say
ReplyDeletecross domain policy or security model which prevents or Cross domain calls..security policy
sivas
ReplyDeletebilecik
denizli
erzincan
uÅŸak
MBSM