Chart Area Series

AreaSeries are a type of CategoricalSeries that present categorical data as points connected with a line and then fill the are between the line and the category axis. The are chart usually visualizes a trend in data over intervals of time, but can also be used to show comparisons among discrete categories.

Setup
References

Setup

To display an Area Chart, you will need to:

Add a RadCartesianChart to your page.
Set the chart's horizontalAxis to a category axis (CategoricalAxis, DateTimeCategoricalAxis or DateTimeContinuousAxis).
Set the chart's verticalAxis to a value axis (LinearAxis or LogarithmicAxis).
Add at least one instance of AreaSeries to the chart's series property and set its items property to a collection of data items, its categoryProperty set to the name of the property of the data items that will be used to determine their category and its valueProperty to the name of the property used to determine their value.

To illustrate this setup, let's create an example. First we will create a source with items:

Example 1: Define a source with data

get categoricalSource() {
    return [
        { Country: "Germany", Amount: 15, SecondVal: 14, ThirdVal: 24 },
        { Country: "France", Amount: 13, SecondVal: 23, ThirdVal: 25 },
        { Country: "Bulgaria", Amount: 24, SecondVal: 17, ThirdVal: 23 },
        { Country: "Spain", Amount: 11, SecondVal: 19, ThirdVal: 24 },
        { Country: "USA", Amount: 18, SecondVal: 8, ThirdVal: 21 }
    ];
}

We use an instance of this model to assign it as the bindingContext of the page we have put our Area series on:

Example 2: Update bindingContext

import { CategoricalDataModel } from "../../data-models/categorical-data-model";

export function onPageLoaded(args) {
    const page = args.object;
    page.bindingContext = new CategoricalDataModel();
}

And finally, in the XML definition of the page we put a RadCartesianChart, add a AreaSeries instance to it and bind the series to the source of data:

Example 3: Add chart to page's markup

<navigation:ExamplePage xmlns:navigation="navigation/example-page" loaded="onPageLoaded" xmlns:chart="nativescript-ui-chart" xmlns="http://www.nativescript.org/tns.xsd">
    <chart:RadCartesianChart id="cartesianChart">
        <chart:RadCartesianChart.horizontalAxis>
            <chart:CategoricalAxis/>
        </chart:RadCartesianChart.horizontalAxis>
        <chart:RadCartesianChart.verticalAxis>
            <chart:LinearAxis />
        </chart:RadCartesianChart.verticalAxis>
        <chart:RadCartesianChart.series>
            <chart:AreaSeries items="{{ categoricalSource }}" categoryProperty="Country" valueProperty="Amount">
            </chart:AreaSeries>
        </chart:RadCartesianChart.series>
    </chart:RadCartesianChart>
</navigation:ExamplePage>

Figure 1: Chart with AreaSeries on Android (left) and iOS (right)

Cartesian chart: Area series

References

Want to see this scenario in action? Check our SDK examples repo on GitHub. You will find this and many other practical examples with NativeScript UI.

Examples used in this article:

Area Series Example

NativeScript Core