Bind Remote Complex Data Kendo DataSource

[jwize]

It would be nice to send some meta information about the data along with the records. 

I want to dynamically show series based on the value of one of the bound fields in the datasource. If there are no records I don't want to show a donut chart ring for example.

Currently, I have to resort to some brittle logic in the change event of the datasource to do the trick. 

change: function (e) {

    var item = this.data()[0];
    var chart = $("#training-chart").data("kendoChart");


    // find the empty donut items.
    if (item.numberCompleted == 0)
        chart.options.series.splice(0, 1);
    if(item.numberExpired == 0)
        chart.options.series.splice(1, 1);
    if (item.numberNotTaken == 0)
        chart.options.series.splice(2, 1);
    if (item.numberDue == 0)
        chart.options.series.splice(3, 1);
    chart.refresh();
},

If I could create a datasource that would look more like the following:

data =
{
      metaproperty : someUsefulInfo,
      chartData  : [ { data: 1 }, { data: 2 },{ data: 3 }]
}

If I could then bind the chartData as my chart datasource instead of the data starting at the root that would be great!

[jwize]

I have figured out that I can solve half the problem by using the schema property on the datasource. Unfortunately, I am only able to access the array of data items but not the original data. 

dataSource: {
    transport: {
        read: {
            url: "/Training/TrainingChartData",
            dataType: "json",
        }
    },
    change: function (e, o, i) {

        // arguments.callee.caller.caller.caller.caller.arguments

        var item = this.data()[0];
        var chart = $("#training-chart").data("kendoChart");

        // find the empty donut items.
        if (item.numberCompleted == 0)
            chart.options.series.splice(0, 1);
        if(item.numberExpired == 0)
            chart.options.series.splice(1, 1);
        if (item.numberNotTaken == 0)
            chart.options.series.splice(2, 1);
        if (item.numberDue == 0)
            chart.options.series.splice(3, 1);
        chart.refresh();
    },
    schema: {
        data: "results"
    }
},

With this in place I can send down the data as described but the meta data is inaccessible except by using the hideous code commented out in the above code.  Please add a second parameter to the "Change" callback with the payload of the original data so that I can get at more elegantly. 

So for now I will have to use 

try
  {
 var meta =  arguments.callee.caller.caller.caller.caller.arguments[0].meta
  }
catch(err)
  {
     alert("oh no, the implementation has changed");
  }

That is unless there is an easier way that I missed. 

[Iliana Dyankova]

Hi Jaime,

Apologies for not getting back to you earlier.

I am afraid your scenario is not supported out-of-the-box - Kendo UI Chart is designed to operate with flat data. As another workaround you could parse the collection in dataSource.schema.parse before assigning it as data of the Chart. 

Regards,
Iliana Nikolova
Telerik