Range Bar Chart

The Blazor Range Bar Chart displays data as horizontal bars whose position and length vary according to pairs of from and to values. You can use a Range Bar Chart to show a comparison between several sets of data (for example, summaries of quantitative or time data). Each series is automatically colored differently for easier reading. The Range Bar Chart is similar to the Bar Chart, which can be regarded as a Range Bar Chart with zero from values.

This article assumes you are familiar with the chart basics and data binding.

Creating Blazor Range Bar Chart

1. Add a ChartSeries to the ChartSeriesItems collection.
2. Set the series Type parameter to ChartSeriesType.RangeBar.
3. Provide a data collection to the series Data parameter. You can use a collection of arrays or a collection of custom objects.
4. If the Range Bar data is a collection of arrays, provide data for the Categories parameter of the ChartCategoryAxis.
5. (optional) Set Visible="true" or define label Template for <ChartSeriesLabelsFrom> or <ChartSeriesLabelsTo>. These are nested tags inside <ChartSeriesLabels> of the respective <ChartSeries>.

Binding Range Bar Series to Collection of Arrays

Set the ChartSeries Data parameter to a List of arrays or a jagged array (an array of arrays). The inner arrays must have two members—a lower one for the from value, and a higher one for to value.

Set the Categories parameter of the ChartCategoryAxis to object[]. The members of this array will be used as labels for the category axis in their respective order.

Blazor Range Bar Chart bound to arrays

<TelerikChart>
    <ChartTitle Text="Sleep Hours by Age"></ChartTitle>

    <ChartSeriesItems>
        <ChartSeries Type="ChartSeriesType.RangeBar" Data="@SleepData">
            <ChartSeriesLabels>
                @* Show the From and To labels together *@

                <ChartSeriesLabelsFrom Visible="false" />
                <ChartSeriesLabelsTo Visible="true" />

                @* OR show the From and To labels separately *@

                @*<ChartSeriesLabelsFrom Visible="true" Template="#= dataItem[0] #" />
                    <ChartSeriesLabelsTo Visible="true" Template="#= dataItem[1] #" />*@
            </ChartSeriesLabels>
        </ChartSeries>
    </ChartSeriesItems>

    <ChartCategoryAxes>
        <ChartCategoryAxis Categories="@Categories"></ChartCategoryAxis>
    </ChartCategoryAxes>

    <ChartValueAxes>
        <ChartValueAxis Min="6"></ChartValueAxis>
    </ChartValueAxes>

    <ChartTooltip Visible="true">
        <Template>
            @{
                var dataItem = (int[])context.DataItem;
            }
            <span>@dataItem[0] - @dataItem[1] hours</span>
        </Template>
    </ChartTooltip>

</TelerikChart>

@code {
    private List<int[]> SleepData = new List<int[]>() {
        new int[] { 7, 8 },
        new int[] { 7, 9 },
        new int[] { 8, 10 },
        new int[] { 9, 12 },
        new int[] { 10, 13 },
        new int[] { 11, 14 },
        new int[] { 12, 16 },
        new int[] { 14, 17 },
    };

    private string[] Categories = new string[] {
        "60+ y", "18-60 y", "13-18 y", "6-12 y", "3-5 y", "1-2 y", "4-12 m", "0–3 m"
    };
}

Binding Range Column Series to Custom Objects

1. Set the ChartSeries Data parameter to an IEnumerable<T>.
2. Set the FromField, ToField, and CategoryField parameters of the ChartSeries to properties of the T type.

Blazor Range Bar Chart bound to custom objects

<TelerikChart>
    <ChartTitle Text="Sleep Hours by Age"></ChartTitle>

    <ChartSeriesItems>
        <ChartSeries Type="ChartSeriesType.RangeBar"
                     Data="@SleepData"
                     FromField="@(nameof(RangeBarModel.LowValue))"
                     ToField="@(nameof(RangeBarModel.HighValue))"
                     CategoryField="@(nameof(RangeBarModel.AgeGroup))">
            <ChartSeriesLabels>
                @* Show the From and To labels together *@

                <ChartSeriesLabelsFrom Visible="false" />
                <ChartSeriesLabelsTo Visible="true" />

                @* OR show the From and To labels separately *@

                @*<ChartSeriesLabelsFrom Visible="true" Template="#= dataItem.LowValue #" />
                    <ChartSeriesLabelsTo Visible="true" Template="#= dataItem.HighValue #" />*@
            </ChartSeriesLabels>
        </ChartSeries>
    </ChartSeriesItems>

    <ChartValueAxes>
        <ChartValueAxis Min="6"></ChartValueAxis>
    </ChartValueAxes>

    <ChartTooltip Visible="true">
        <Template>
            @{
                var dataItem = (RangeBarModel)context.DataItem;
            }
            <span>@dataItem.LowValue - @dataItem.HighValue hours</span>
        </Template>
    </ChartTooltip>

</TelerikChart>

@code {
    private List<RangeBarModel> SleepData = new List<RangeBarModel>() {
        new RangeBarModel { LowValue = 7, HighValue = 8, AgeGroup = "60+ y" },
        new RangeBarModel { LowValue = 7, HighValue = 9, AgeGroup = "18-60 y" },
        new RangeBarModel { LowValue = 8, HighValue = 10, AgeGroup = "13-18 y" },
        new RangeBarModel { LowValue = 9, HighValue = 12, AgeGroup = "6-12 y" },
        new RangeBarModel { LowValue = 10, HighValue = 13, AgeGroup = "3-5 y" },
        new RangeBarModel { LowValue = 11, HighValue = 14, AgeGroup = "1-2 y" },
        new RangeBarModel { LowValue = 12, HighValue = 16, AgeGroup = "4-12 m" },
        new RangeBarModel { LowValue = 14, HighValue = 17, AgeGroup = "0-3 m" }
    };

    public class RangeBarModel
    {
        public string AgeGroup { get; set; }
        public int LowValue { get; set; }
        public int HighValue { get; set; }
    }
}

Range Bar Chart Specific Appearance Settings

Color

The color of a series is controlled through the Color property that can take any valid CSS color (for example, #abcdef, #f00, or blue). The color controls the fill color of the area.

Color Field

Bar and Column charts can take the color of the series item from the ColorField of the data source. You can pass a valid CSS color (for example, #abcdef, #f00, or blue).

Colors per series item

<TelerikChart>
    <ChartSeriesItems>
        <ChartSeries Type="ChartSeriesType.Bar" Data="@theData" ColorField="@nameof(MyChartDataModel.Color)"
                            Field="@nameof(MyChartDataModel.ItemValue)" CategoryField="@nameof(MyChartDataModel.Category)" />
    </ChartSeriesItems>

    <ChartTitle Text="Revenue per product" />

    <ChartLegend Position="ChartLegendPosition.Right" />
</TelerikChart>

@code {
    public class MyChartDataModel
    {
        public string Category { get; set; }
        public double ItemValue { get; set; }
        public string Color { get; set; }
    }

    public List<MyChartDataModel> theData = new List<MyChartDataModel>
    {
        new MyChartDataModel
        {
            Category = "Product 1",
            ItemValue = 2,
            Color = "red"
        },
        new MyChartDataModel
        {
            Category = "Product 2",
            ItemValue = 3,
            Color = "#00ff00"
        },
        new MyChartDataModel
        {
            Category = "Product 3",
            ItemValue = 4,
            Color = "#00f"
        }
    };
}

Gap and Spacing

You can control the distance between the categories that cluster a data point from each series. To do this, use the Gap property of the series. It is the distance between categories expressed as a percentage of the bar width.

To set the distance between the bars of different series in the same category, use the Spacing property. It is the space between the series items in one series category as a proportion of the width of a single series item.

To create overlap, set negative values.

You can configure the values of Gap and Spacing for the whole chart in the first series and they are applied for all categories and series items.

Customize Chart Elements - Nested Tags Settings

When configuring nested properties and child elements in your chart, the inner tags will contain their parent tag name and add specifics to its end. In general the structure of such nested tags will be <Chart*Category**Specifics*> where the Category can be one of the following:

• CategoryAxis
• ChartArea
• Legend
• PlotArea
• SeriesItems
• Title
• Tooltip
• ValueAxis
• XAxes
• YAxes
• and others

To customize the chart, look for nested tags and their properties - the inner tags will contain their parent tag name and add specifics to its end. For example, the ChartSeries tag has a ChartSeriesLabels tag that exposes configuration options and more child tags.

An example of this is the rotation the Labels of a categorical chart. You can use the

ChartCategoryAxes > ChartCategoryAxis > ChartCategoryAxisLabels > ChartCategoryAxisLabelsRotation tag

and set the Angle property to the desired value in degrees (they might be negative or positive numbers). By using similar approach you can take control over ChartCategoryAxisLabelsMargin (add margin for top, bottom, left and right), ChartCategoryAxisLabelsPadding (add padding for top, bottom, left and right) and others.

This approach is not limited only to the Labels - it can be used with all tags that are applicable for the chart type, for example the Chart Title ChartTitle > ChartTitleMargin.

See Also

• Live Demo: Range Bar Chart