Calling a WCF Data Service From jQuery

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.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Gil Fink

Architect Sela Group

Israel

Member

Gil Fink is an expert in ASP.NET and Microsoft data platform and serves as a Senior Architect at SELA Group. He is a Microsoft data platform MVP and a certified MCPD Enterprise Application Developer. Gil has worked in the past in variety of positions and projects as a leading developer, team leader, consultant and more. His interests include Entity Framework, Enterprise Library, WCF, LINQ, ADO.NET and many other new technologies from Microsoft.

My technical blog: http://www.gilfink.net

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A Technical Blog, originally posted at http://feeds.feedburner.com/GilFinkBlog

I want to show is how easy and simple it is to consume a WCF Data Service (OData feed) with the jQuery library.

Type	Technical Blog
Licence	CPOL
First Posted	18 Jul 2010
Views	13,660
Bookmarked	9 times

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