Working with Data in ASP.NET Core Chart control

25 Oct 2021 / 2 minutes to read

Chart can visualise data bound from local or remote data.

Local Data

You can bind a simple JSON data to the chart using dataSource property in series. Now map the fields in JSON to xName and yName properties.

tagHelper

local-data.cs

<ejs-chart id="container" title="Inflation - Consumer Price" width="60%">
        <e-chart-primaryxaxis valueType="DateTime"
                              labelFormat="y"
                              intervalType="Years"
                              edgeLabelPlacement="Shift"></e-chart-primaryxaxis>
        <e-series-collection>
            <e-series dataSource="ViewBag.dataSource" name="Germany" xName="xValue" width="2" opacity="1" yName="yValue" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Line"></e-series>
        </e-series-collection>
    </ejs-chart>

public IActionResult Index()
        {
           List<LineData> chartData = new List<LineData>
            {
                new LineData { xValue = new DateTime(2005, 01, 01), yValue = 21, yValue1 = 28 },
                new LineData { xValue = new DateTime(2006, 01, 01), yValue = 24, yValue1 = 44 },
                new LineData { xValue = new DateTime(2007, 01, 01), yValue = 36, yValue1 = 48 },
                new LineData { xValue = new DateTime(2008, 01, 01), yValue = 38, yValue1 = 50 },
                new LineData { xValue = new DateTime(2009, 01, 01), yValue = 54, yValue1 = 66 },
                new LineData { xValue = new DateTime(2010, 01, 01), yValue = 57, yValue1 = 78 },
                new LineData { xValue = new DateTime(2011, 01, 01), yValue = 70, yValue1 = 84 },
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class LineData
        {
            public DateTime xValue;
            public double yValue;
            public double yValue1;
        }

Common Datasource

You can also bind a JSON data common to all series using dataSource property in chart.

Remote Data

You can also bind remote data to the chart using DataManager. The DataManager requires minimal information like webservice URL, adaptor and crossDomain to interact with service endpoint properly. Assign the instance of DataManager to the dataSource property in series and map the fields of data to xName and yName properties. You can also use the query property of the series to filter the data.

tagHelper

remote-data.cs

<ejs-chart id="lineContainer">

        <e-chart-primaryxaxis title="Assignee" rangePadding="Additional" valueType="Category"></e-chart-primaryxaxis>
        <e-series-collection>
            <e-series name="Story Point" xName="Assignee" width=2 yName="Estimate" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Column" query="new ej.data.Query().take(5).where('Estimate', 'lessThan', 3, false)">
                <e-data-manager url='https://mvc.syncfusion.com/Services/Northwnd.svc/Tasks/' crossdomain="true"></e-data-manager>
                <e-series-marker>
                    <e-series-datalabel visible="true" position="Top"></e-series-datalabel>
                </e-series-marker>
                <e-series-animation enable="false"></e-series-animation>
            </e-series>
        </e-series-collection>
    </ejs-chart>

public ActionResult Index()
        {

            return View();
            
        }

Empty points

The Data points that uses the null or undefined as value are considered as empty points. Empty data points are ignored and not plotted in the Chart. When the data is provided by using the points property, By using emptyPointSettings property in series, you can customize the empty point. Default mode of the empty point is Gap.

tagHelper

empty-points.cs

<ejs-chart id="container" title="Inflation - Consumer Price" width="60%">
        <e-chart-primaryxaxis valueType="Category"></e-chart-primaryxaxis>
        <e-series-collection>
            <e-series dataSource="ViewBag.dataSource" name="Germany" xName="month" width="2" opacity="1" yName="sales" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Column">
                <e-series-emptypointsettings mode="@Syncfusion.EJ2.Charts.EmptyPointMode.Gap"></e-series-emptypointsettings>
            </e-series>
        </e-series-collection>
    </ejs-chart>

public IActionResult Index()
        {
            List<EmptyData> chartData = new List<EmptyData>
            {
               new EmptyData{ month="Jan", sales= 35 },
               new EmptyData{ month= "Feb", sales= 28 },
               new EmptyData{ month="Mar", sales=null },
               new EmptyData{ month="Apr", sales=32 },
               new EmptyData{ month="May", sales=40 },
               new EmptyData{ month= "Jun", sales=32 },
               new EmptyData{ month="Jul", sales=35 },
               new EmptyData{ month="Aug", sales=null },
               new EmptyData{ month="Sep", sales=38 },
               new EmptyData{ month="Oct", sales=30 },
               new EmptyData{ month="Nov", sales=25 },
               new EmptyData{ month= "Dec", sales=32 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class EmptyData
        {
            public string month;
            public Nullable<double> sales;
        }

Lazy loading

Lazy loading allows you to load data for chart on demand. Chart will fire the scrollEnd event, in that we can get the minimum and maximum range of the axis, based on this, we can upload the data to chart.

tagHelper

<ejs-chart id="container" load="window.onChartLoad" scrollEnd="scrollEnd">
            <e-chart-chartarea>
                <e-chartarea-border width="0"></e-chartarea-border>
            </e-chart-chartarea>
            <e-chart-primaryxaxis edgeLabelPlacement="Shift" title="Day" valueType="DateTime" skeleton="yMMM" skeletonType="Date">
                <e-scrollbarSettings enable="true" pointsLength="1000"></e-scrollbarSettings>
                <e-majorgridlines width="0"></e-majorgridlines>
            </e-chart-primaryxaxis>
            <e-chart-primaryyaxis interval="10" title="Server Load" labelFormat="{value}MB">
                <e-majorticklines width="0"></e-majorticklines>
                <e-linestyle width="0"></e-linestyle>
            </e-chart-primaryyaxis>
            <e-series-collection>
                <e-series xName="x" yName="y" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Line">
                    <e-series-animation enable="false"></e-series-animation>
                </e-series>
            </e-series-collection>
            <e-chart-tooltipsettings enable="true" shared="true"></e-chart-tooltipsettings>
            <e-chart-legendsettings visible="false"></e-chart-legendsettings>
            <e-chart-legendsettings visible="false"></e-chart-legendsettings>
        </ejs-chart>

        <script>
              var intl = new ej.base.Internationalization();
        var chart;
            function scrollEnd(args) {
            if (modeType.value === 'Range') {
                chart.series[0].dataSource = GetDateTimeData(args.currentRange.minimum, args.currentRange.maximum);
            } 
            chart.dataBind();

        }
        </script>

        window.onChartLoad = function (args) {
            args.chart.series[0].dataSource = GetDateTimeData(new Date(2009, 0, 1), new Date(2009, 8, 1)),
            args.chart.primaryXAxis.scrollbarSettings.range = { minimum: new Date(2009, 0, 1), maximum: new Date(2014, 0, 1) }

        }
           function GetDateTimeData(start, end) {
            var series1 = [];
            var date;
            var value = 30;
            var option = { skeleton: 'full', type: 'dateTime' };

            var dateParser = intl.getDateParser(option);
            var dateFormatter = intl.getDateFormat(option);
            for (var i = 0; start <= end; i++) {
                date = Date.parse(dateParser(dateFormatter(start)));
                if (Math.random() > .5) {
                    value += (Math.random() * 10 - 5);
                } else {
                    value -= (Math.random() * 10 - 5);
                }
                if (value < 0) {
                    value = getRandomInt(20, 40);
                }
                var point1 = { x: new Date(date), y: Math.round(value) };
                new Date(start.setDate(start.getDate() + 1));
                series1.push(point1);
            }
            return series1;
        }
       function getRandomInt(min, max) {
            return Math.floor(Math.random() * (max - min + 1)) + min;
        }

**Customizing empty point**

Specific color for empty point can be set by fill property in emptyPointSettings. Border for a empty point can be set by border property.

tagHelper

custom-emptypoint.cs

<ejs-chart id="container" title="Inflation - Consumer Price" width="60%">
        <e-chart-primaryxaxis valueType="Category"></e-chart-primaryxaxis>
        <e-series-collection>
            <e-series dataSource="ViewBag.dataSource" name="Germany" xName="month" width="2" opacity="1" yName="sales" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Column">
                <e-series-emptypointsettings fill="#e6e6e6" mode="@Syncfusion.EJ2.Charts.EmptyPointMode.Average"></e-series-emptypointsettings>
            </e-series>
        </e-series-collection>
    </ejs-chart>

public IActionResult Index()
        {
            List<EmptyData> chartData = new List<EmptyData>
            {
               new EmptyData{ month="Jan", sales= 35 },
               new EmptyData{ month= "Feb", sales= 28 },
               new EmptyData{ month="Mar", sales=null },
               new EmptyData{ month="Apr", sales=32 },
               new EmptyData{ month="May", sales=40 },
               new EmptyData{ month= "Jun", sales=32 },
               new EmptyData{ month="Jul", sales=35 },
               new EmptyData{ month="Aug", sales=null },
               new EmptyData{ month="Sep", sales=38 },
               new EmptyData{ month="Oct", sales=30 },
               new EmptyData{ month="Nov", sales=25 },
               new EmptyData{ month= "Dec", sales=32 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class EmptyData
        {
            public string month;
            public Nullable<double> sales;
        }

Contents

Local Data
Common Datasource
Remote Data
Empty points
Lazy loading

Contents

Local Data
Common Datasource
Remote Data
Empty points
Lazy loading

Please provide additional information

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