Custom Interactivity in the Web Dashboard

• Oct 03, 2022
• 3 minutes to read

Dashboard Item Interactivity

Along with built-in master filtering and drill-down, data-bound dashboard items in which you can select and highlight elements also support custom visual interactivity. The ViewerApiExtensionOptions.onItemVisualInteractivity event is raised for dashboard items with disabled master filtering. The Web Dashboard control also fires this event when a user applies master filtering to the current dashboard item or changes the drill-down level in this dashboard item.

You can use the following event arguments:

e.itemName

Gets the component name of the dashboard item for which the event was raised.

e.setTargetAxes

Sets data axes used to perform custom interactivity actions.

e.setSelectionMode

Sets the selection mode for dashboard item elements.

e.enableHighlighting

Specifies whether to enable highlighting for the current dashboard item.

e.setDefaultSelection

Sets the default selection for the current dashboard item.

Selection changes raise the ViewerApiExtensionOptions.onItemSelectionChanged event. Its e.getCurrentSelection method returns the selected elements.

The following table lists possible target axes for each dashboard item and supported interactivity capabilities:

Dashboard Item	Target Axes	Selection	Highlighting
GridItem	Default
ChartItem	Argument Series
ScatterChartItem	Argument
PieItem	Argument Series
CardItem	Default
GaugeItem	Default
MapItem	Default
TreemapItem	Default

Note that the Grid dashboard item does not support custom interactivity when Cell Merging is enabled.

Custom Item Interactivity

You can implement a master filter and drill-down for custom dashboard items. Refer to the following topic for details: Implement a Custom Item Interactivity.

Example

The Web Dashboard allows you to add custom interactivity to dashboards. For this, handle the ViewerApiExtensionOptions.onItemVisualInteractivity event. You can get data axes used to apply custom interactivity actions, specify the selection mode for dashboard item elements and so on. Use event arguments to process the multidimensional data to get the slice, axes, or tuples.

The change of the selection in the dashboard item raises the ViewerApiExtensionOptions.onItemSelectionChanged event.

• Select categories in the Grid dashboard item to visualize its quantity in the dxBarGauge widget. The hidden ‘Quantity’ measure is used to pass values to the client.

  

• The Chart dashboard item highlights bars corresponding to a hovered argument value.

  

View Example: ASP.NET Core

CustomInteractivity.js

var dimensionValues = [];

function onBeforeRender(dashboardControl) {
    if (dashboardControl) {
        dashboardControl.on('dashboardEndUpdate', createControls);
        var viewerApiExtension = dashboardControl.findExtension("viewerApi");
    }
    if (viewerApiExtension) {
        viewerApiExtension.on('itemVisualInteractivity', addCustomInteractivity);
        viewerApiExtension.on('itemSelectionChanged', applyCurrentSelection);
    }
}

function addCustomInteractivity(args) {
    if (args.itemName == "gridDashboardItem1") {
        args.setTargetAxes(["Default"]);
        args.setSelectionMode("Multiple");
    }
    if (args.itemName == "chartDashboardItem1") {
        args.setTargetAxes(["Argument"]);
        args.enableHighlighting(true);
    }
}

function createControls() {
    $('#barGauge').dxBarGauge({
        startValue: 0,
        endValue: 10000,
        values: getAllValues(),
        title: {
            text: "Product Quantity",
            font: {
                size: 28,
            }
        },
        label: {
            format: 'fixedPoint',
            precision: 0
        },
        tooltip: {
            enabled: true,
            customizeTooltip(arg) {
                return {
                    text: getText(dimensionValues[arg.index], arg.value),
                };
            },
        },
        legend: {
            visible: true,
            verticalAlignment: 'bottom',
            horizontalAlignment: 'center',
            customizeText(arg) {
                return getText(dimensionValues[arg.item.index], arg.text);
            }
        }
    });
}

function getText(item, text) {
    return `${item} - ${text}`    
}

function applyCurrentSelection(args) {
    var quantityValues = [];
    dimensionValues = [];
    if (args.itemName == "gridDashboardItem1" & args.getCurrentSelection().length != 0) {
        var viewerApiExtension = dashboardControl.findExtension('viewerApi');
        var clientData = viewerApiExtension.getItemData("gridDashboardItem1");
        for (var i = 0; i < args.getCurrentSelection().length; i++) {
            var dimensionValue = args.getCurrentSelection()[i].getAxisPoint().getValue();
            var currentTuple = args.getCurrentSelection()[i],
                slice = clientData.getSlice(currentTuple.getAxisPoint()),
                quantity = (slice.getMeasureValue(clientData.getMeasures()[0].id)).getValue();            
            quantityValues.push(quantity);
            dimensionValues.push(dimensionValue);
        }
    } else {
        quantityValues = getAllValues();
    }
    $("#barGauge").dxBarGauge("instance").values(quantityValues);
}

function getAllValues() {
    var viewerApiExtension = dashboardControl.findExtension('viewerApi');
    dimensionValues = [];
    var quantityValues = [];
    var   clientData = viewerApiExtension.getItemData("gridDashboardItem1");
    for (var i = 0; i < clientData.getAxis("Default").getPoints().length; i++) {
        var slice = clientData.getSlice(clientData.getAxis("Default").getPoints()[i]),
            quantity = (slice.getMeasureValue(clientData.getMeasures()[0].id)).getValue(),
            dimensionValue = clientData.getAxis("Default").getPoints()[i].getValue();        
        quantityValues.push(quantity);
        dimensionValues.push(dimensionValue);
    }
    return quantityValues;
}

Index.cshtml

@page
@using DevExpress.DashboardWeb

<div style="display: inline-block; float: left;">
@(Html.DevExpress().Dashboard("dashboardControl")
    .ControllerName("DefaultDashboard")
    .Width("600px")
    .Height("750px")
    .OnBeforeRender("onBeforeRender")
    .WorkingMode(WorkingMode.Viewer)
)
</div>

<div id="barGauge" style="display: inline-block; float: left; width: 600px; height: 375px;"></div>