Calling a WCF Data Service From jQuery
I want to show is how easy and simple it is to consume a WCF Data Service (OData feed) with the jQuery library.
Introduction
I'm working on a lecture about OData which I will present next month (stay tuned for more details in the near future). One of the things that I want to show is how easy and simple it is to consume a WCF Data Service (OData feed) with the jQuery library.
In this post, I'll show you exactly how to do that.
jQuery’s getJSON Method
When you want to load JSON data from the server using a GET HTTP request in jQuery, you will probably use the getJSON method. That method gets as input the server URL, a map of key-value pairs which holds parameters to the server and a callback function to use when the response arrives back to the client and returns the server response in JSON format. This method is the best candidate for consuming WCF Data Services endpoints. If I want to use the getJSON method, I'll do something like the example provided in the getJSON documentation:
$.getJSON('ajax/test.json', function(data) {
$('.result').html('<p>' + data.foo + '</p>'
+ '<p>' + data.baz[1] + '</p>');
});
How to Consume WCF Data Service with jQuery getJSON Method
When we understand that WCF Data Service is just an HTTP endpoint which returns JSON answer if addressed with JSON request, the road is very clear. If I want to consume the service, all I need to do is create the relevant URI with the WCF Data Service URI conventions and that is it. The following code is an example for that:
$.getJSON("/Services/SchoolService.svc/Courses", null,
function (data) {
var sb = new Sys.StringBuilder();
sb.append("<div>");
$.each(data.d, function (i, item) {
CreateDivForOneCourse(sb, item)
});
sb.append("</div>");
$('#divResults').html(sb.toString());
});
What this code is doing is it goes to a WCF Data Service endpoint that is called SchoolService.svc and retrieves the courses entity set it holds. I don’t pass any parameters to the request so the key-value pair is null. In the callback function, I create a StringBuilder object and append to it the response by iterating the data and creating a div for every course. In the end, I put the result as HTML in a div which has an id of divResults.
The All Example Page
<%@ Page Language="C#" AutoEventWireup="true"
CodeBehind="ConsumeDataServicejQuery.aspx.cs"
Inherits="DataServiceAjaxClient.ConsumeDataService.ConsumeDataServicejQuery" %>
<!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="../Content/Scripts/jquery-1.4.1.js" type="text/javascript"></script>
<script src="../Content/Scripts/jquery-1.4.1-vsdoc.js" type="text/javascript">
</script>
<script type="text/javascript">
var ajaxRequest;
$(document).ready(function () {
$('#btnShowCourses').click(function () {
GetCoursesData();
});
});
function GetCoursesData() {
if (ajaxRequest != null) {
ajaxRequest.abort();
}
ajaxRequest = $.getJSON("/Services/SchoolService.svc/Courses", null,
function (data) {
var sb = new Sys.StringBuilder();
sb.append("<div>");
$.each(data.d, function (i, item) {
CreateDivForOneCourse(sb, item)
});
sb.append("</div>");
$('#divResults').html(sb.toString());
});
}
function CreateDivForOneCourse(stringBuilder, item) {
stringBuilder.append("<div><span>");
stringBuilder.append(item.CourseID);
stringBuilder.append("</span> <span>");
stringBuilder.append(item.Title);
stringBuilder.append("</span></div>");
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<input type="button" id="btnShowCourses" value="Show Courses" /><br />
<div id="divResults" />
</div>
</form>
</body>
</html>
After running this example, the result looks like:
Summary
Consuming WCF Data Services with jQuery is a very easy task. By using the getJSON method, we create the HTTP GET request to the service and get the returning data in JSON format to
our disposal.