problem with WinJS.xhr with WCF rest post method

Question

The JSON data is not passing to WCF via winjs.xhr. Its always passing the value as null to WCF method .

Can anybody help to resolve this issue with an example. I am using WebInvoke method=POST etc and passing the data with json.stringify

Answer 1

Hi,

One point I want to say, you have to handle the function in winjs.xhr().then(), but after that.

For example:

 var feedItems = [];


    function loadBlogFeedsFromWebAsXML() {

        var feedUrl = "http://blogs.msdn.com/b/windowsstore/rss.aspx";

        WinJS.xhr({ url: feedUrl }).then(
        function (result) {

            var xmlDoc = new Windows.Data.Xml.Dom.XmlDocument();
            xmlDoc.loadXml(result.responseText);

            var nodes = xmlDoc.selectNodes("//item");

            var items = new Array();

            nodes.forEach(function (val, idx, travObj) {

                var title = val.selectSingleNode("title").innerText;
                var description = val.selectSingleNode("description").innerText;
                var link = val.selectSingleNode("link").innerText;

                var newItem = {
                    title: title,
                    summary: description,
                    uri: link
                };

                items.push(newItem);
            });

            DataUtils.feedItems = items;


            // Call other function which you want to do
        },
        function (err) {
        }
        );

        return DataUtils.feedItems;
    }





    WinJS.Namespace.define(
        "DataUtils", {
            feedItems: feedItems
        }
        );

---

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Answer 2

d
IStudent.cs
***********
[WebInvoke(Method = "POST", UriTemplate = "/GetStudentDataInput", ResponseFormat = WebMessageFormat.Json, BodyStyle=WebMessageBodyStyle.WrappedResponse)]
string GetStudentDataInput(string id);
Student.svc.cs
**************
  public string GetStudentDataInput(string id)
  {
    return id;
   }
WinJS call to WCF
*****************
 function CallData() {
 
       var person = { "Name": "Name", "Age": 24 };
             WinJS.xhr({
                type: "POST",                
                url: "http://localhost:9814/Student.svc/GetStudentDataInput",
                data: JSON.stringify(person)
            }).then(function complete(request) {
               stuListNew = JSON.parse(request.responseText);
            }, function error(er) {
                var err = er.responseText;
            });
 }
Web.config
************
 <system.serviceModel>
    <services>
      <service name="StudentService.Service1" behaviorConfiguration="ServiceBehaviour">
        <endpoint binding="webHttpBinding" contract="StudentService.IStudent" behaviorConfiguration="webhttpconfig"></endpoint>
      </service>
    </services>
    <behaviors>   
      <serviceBehaviors>       
        <behavior name="ServiceBehaviour">         
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="true"/>
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="webhttpconfig">
          <webHttp/>
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <protocolMapping>
        <add binding="webHttpBinding" scheme="http"  />
    </protocolMapping>    
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
  </system.serviceModel>
Please find the above code snippet which we are using for WinJS to WCF. 
Always the value which we passing from WinJS.xhr is coming as null in  public string GetStudentDataInput(string id).

 

Answer 3

Hi,

You forget to define the contenttype in headers, so just change the code as follow:

function CallData() {
 
       var person = { "Name": "Name", "Age": 24 };
             WinJS.xhr({
                type: "POST",                
                url: "http://localhost:9814/Student.svc/GetStudentDataInput",
                headers: { "Content-type": "application/json; charset=utf-8" },
                data: JSON.stringify(person)
            }).then(function complete(request) {
               stuListNew = JSON.parse(request.responseText);
            }, function error(er) {
                var err = er.responseText;
            });
 }

---

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If you have any feedback about my replies, please contact [e-mail]
Microsoft One Code Framework

Answer 4

 Issue got resolved. I was given json value in wrong format which caused the issue.

var person = { "Name": "Name", "Age": 24 };

var person = '{"Name":"Name", "Age":"30"}';

function CallData() {
 
	var person = '{"Name":"Name", "Age":"30"}';
             WinJS.xhr({
                type: "POST",                
                url: "http://localhost:9814/Student.svc/GetStudentDataInput",
                headers: { "Content-type": "application/json; charset=utf-8" },
                data: JSON.stringify(person)
            }).then(function complete(request) {
               stuListNew = JSON.parse(request.responseText);
            }, function error(er) {
                var err = er.responseText;
            });
 }