Question

what i need to do is load my pie data chart created with extjs4 with data from my database
the store accept this data ,so i need to return my data in format that look like this:

var data = [{ name: "Low", data1: "20", data2: "54", data3: "63", data4: "12" },
 { name: "Moderate", data1: "2", data2: "74", data3: "13", data4: "25" },
 { name: "Critical", data1: "42", data2: "17", data3: "3", data4: "20" },
 { name: "High", data1: "25", data2: "14", data3: "23", data4: "52"}];

so im trying to do this in c# with json.net, i created a class.cs and put my queries to get the data i need :

namespace charts
{
public class lineChartClass
{
    public String piedata()
    {     
{//..my queries in here..//}
   double[] data = new double[4] ;
        //data = "{ name: \"Low\", data1: " + lowtotal + "}" + ",{ name: \"Moderate\", data1: " + moderatetotal + "}" + ",{ name: \"Critical\", data1: " + criticaltotal + "}" + ",{ name: \"High\", data1: " + hightotal + "}";
       data[0]=lowtotal;
       data[1] = moderatetotal;
       data[2] = criticaltotal;
       data[3] = hightotal;
        return data;



    }//eo piedata
}
    public class ChartItem
    {
        public string Name { get; set; }

        public string Data1 { get; set; }


    }

}

and created my handler.ashx to convert to json:

namespace charts {
public class lineChartData : IHttpHandler
{
    static string ConvertToJson()
    {
     List<ChartItem> chartItems = new List<ChartItem>();

        chartItems.Add(new ChartItem() { Name = "Low", Data1 = json[0].ToString() });
        chartItems.Add(new ChartItem() { Name = "Moderate", Data1 = json[1].ToString() });
        chartItems.Add(new ChartItem() { Name = "Critical", Data1 = json[2].ToString() });
        chartItems.Add(new ChartItem() { Name = "High", Data1 = json[3].ToString() });
        string result = new JavaScriptSerializer().Serialize(chartItems);
        return result;

    }
} 
}

then in my chart.js i call it like this:

var obj= new lineChartData();

window.store1 = Ext.create('Ext.data.JsonStore', {
fields: ['name', 'dat1', 'data2', 'data3', 'data4'],
data: obj.ConvertToJson()//generateData()
});

but i get this error:

Uncaught ReferenceError: lineChartData is not defined
lineChartData.ashxGET http://localhost/lineChartData.ashx?proxy 500 (Internal Server Error)

im just starting with c# and extjs and dont know how to use json.net

thanks in advance for ur time

Answer 1

Why don’t you use standard versions of JSON serialization tools at both client-side and server-side.
ASP.NET has JavaScriptSerializer class & JavaScript has JSON object (native in ECMAScript 5 and a plugin for older versions, written by Douglas Crockford).

To convert and Object to JSON at server, you can use:

string objectJson = new JavaScriptSerializer().Serialize(yourObject);

To serialize object to JSON at client-side, you can use:

string objectJson = JSON.stringify(yourObject);

To deserialize a JSON string into an object in client-side, you can use:

var yourObject = JSON.parse(objectJson);

Thus you can have a class to represent your chart item at server:

public class ChartItem
{
    public string Name {get;set;}

    public string Data1 {get;set;}

    public string Data2 {get;set;}

    public string Data3 {get;set;}

    public string Data4 {get;set;}
}

and use it in your `ConvertToJson’ method as follow:

List<ChartItem> chartItems = new List<ChartItem>();
// add as many item as you wish to this list
chartItems.Add(new ChartItem(){ Name = "Something", Data1 = "data1", Data2 = "data2", Data3 = "data3", Data4 = "data4 });
string result = new JavaScriptSerialize().Serialize(chartItems);
return result;