Question

I am making an AJAX call using jQuery to an .ascx control’s method in the code behind to get a list of business objects:

C# Code:

if (Request.Headers["X-OFFICIAL-REQUEST"] == "TRUE") ReturnList(Request.Params[1]);

  protected void ReturnList(string param)
  {
    Response.Write(GetBusinesses(param));
    Response.Flush();
    try {  
         Response.Close(); 
        }
    catch { }
    Response.End();
    return;
  } 

private string GetBusinesses(string classificationName)
{
    System.Web.Script.Serialization.JavaScriptSerializer jSearializer = null;
    if (!string.IsNullOrEmpty(classificationName))
    {
        dSourse = BusinessesDBService.Instance.GetLatestListingsUpdates(classificationName).ToList();
        jSearializer = new System.Web.Script.Serialization.JavaScriptSerializer();
    }
    return jSearializer.Serialize(dSourse);

}

jQuery Code:

window.jQuery.ajax({
    type: "POST",
    async: false,
    url: location.href,
    dataType: "json",
    data: ({ 'FUNCTION': 'ReturnList', 'param0': classificationName.toLowerCase() }),
    success: function (data) {
        data = eval(data);

    },
    error: function (XMLHttpRequest, textStatus, errorThrown) {
    },
    beforeSend: function (xhr) {
        xhr.setRequestHeader("X-OFFICIAL-REQUEST", "TRUE"); //Used to ID as a AJAX Request
    },
    complete: function (XMLHttpRequest, textStatus) {
     //build HTML
        var tablestring = '<table ><tr><td>UsreID" + "</td><td>UserName</td></tr>';

        for (var i = 0, len = data.length; i < len; ++i) {
            tablestring = tablestring + "<tr>";
            tablestring = tablestring + "<td>" +
                data[i].BusinessID + "</td>";
            tablestring = tablestring + "<td>" +
                data[i].BusinessName + "</td>";
            tablestring = tablestring + "</tr>";
        }
        tablestring = tablestring + "</table>";
        var divResult = document.getElementById("divAjax");
        divResult.innerHTML = tablestring;

    }
}); 

The http call is executed fine and the collection is serialized and returned with the response however I have a few problems here. The main one is that the HTML is not being created – I am not able to capture the string returned. The string below shows up in the Firebug script window after the call is complete

[{“BusinessID”:6549,”BusinessName”:”Ivory Store”,”IsMain”:true}, {“BusinessID”:16565,”BusinessName”:”Classic Nails”,”IsMain”},{“BusinessID”:5877,”BusinessName”:”Visible Changes Hair”,”IsMain”:true}]

Also in the Firebug I have noticed that string in XMLHttpRequest response object and the error message is “JSON is not valid” Any suggetions? Thank you very much.

Answer 1

For some reason the code-behind C# parser code below was not appending “]” to the end of the string so I had to append it manually – it worked!!! Thank you.

   public static string Serialize<T>(T obj)
    {
        DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
        MemoryStream ms = new MemoryStream();
        serializer.WriteObject(ms, obj);
        string retVal = Encoding.UTF8.GetString(ms.ToArray());
        return retVal + "]";
    }