datasource

A data source manages raw location data in GeoJSON format locally. Good for small to medium data sets (upwards of hundreds of thousands of shapes).

Adding geometries

Multiple types of Geometries can be added to a data source :

• LineString
• MultiLineString
• MultiPoint
• MultiPolygon
• Point
• Polygon

You can add geometry wrapped into Shapes or Features on a data source using the AddAsync method.

@page "/BubbleLayerOnReady"

@using AzureMapsControl.Components.Map
<AzureMap Id="map"
          CameraOptions="new CameraOptions { Zoom = 2 }"
          EventActivationFlags="MapEventActivationFlags
                                .None()
                                .Enable(MapEventType.Ready)"
          OnReady="OnMapReady" />

@code  {
    public async Task OnMapReady(MapEventArgs events)
    {
        const string dataSourceId = "bubbleDataSource";
        var dataSource = new AzureMapsControl.Components.Data.DataSource(dataSourceId);
        await events.Map.AddSourceAsync(dataSource);


        var geometries = new List<AzureMapsControl.Components.Atlas.Shape>();
        for (var i = 0; i < 10; i++)
        {
            geometries.Add(new AzureMapsControl.Components.Atlas.Shape<AzureMapsControl.Components.Atlas.Point>(new AzureMapsControl.Components.Atlas.Point(new Components.Atlas.Position(i * 5, i * 5))));
        }

        await dataSource.AddAsync(geometries);

        var layer = new AzureMapsControl.Components.Layers.BubbleLayer
        {
            Options = new Components.Layers.BubbleLayerOptions
            {
                Color = new Components.Atlas.ExpressionOrString("white"),
                Radius = new Components.Atlas.ExpressionOrNumber(5),
                StrokeColor = new Components.Atlas.ExpressionOrString("#4288f7"),
                StrokeWidth = new Components.Atlas.ExpressionOrNumber(6),
                Source = dataSourceId
            }
        };

        await events.Map.AddLayerAsync(layer);
    }
}

Importing data

You can import data on the data source using the ImportDataFromUrlAsync method.

@page "/HeatmapLayerOnReady"

@using AzureMapsControl.Components.Map
<AzureMap Id="map"
          CameraOptions="new CameraOptions { Zoom = 2 }"
          StyleOptions="StyleOptions"
          EventActivationFlags="MapEventActivationFlags
                                .None()
                                .Enable(MapEventType.Ready)"
          OnReady="OnMapReady" />

@code  {

    public StyleOptions StyleOptions = new StyleOptions
    {
        Style = MapStyle.GrayscaleDark
    };

    public async Task OnMapReady(MapEventArgs events)
    {
        const string dataSourceId = "heatmapDataSource";
        var dataSource = new AzureMapsControl.Components.Data.DataSource(dataSourceId);
        await events.Map.AddSourceAsync(dataSource);
        await dataSource.ImportDataFromUrlAsync("https://services1.arcgis.com/0MSEUqKaxRlEPj5g/arcgis/rest/services/ncov_cases/FeatureServer/1/query?where=1%3D1&f=geojson&outFields=*");

        var layer = new AzureMapsControl.Components.Layers.HeatmapLayer
        {
            Options = new Components.Layers.HeatmapLayerOptions
            {
                //This will get converted to ['get', 'Confirmed']
                Weight = new Components.Atlas.ExpressionOrNumber(
                    new AzureMapsControl.Components.Atlas.Expression[]
                    {
                        new AzureMapsControl.Components.Atlas.ExpressionOrString("get"),
                        new AzureMapsControl.Components.Atlas.ExpressionOrString("Confirmed"),
                    }
                ),
                Radius = new Components.Atlas.ExpressionOrNumber(20),
                Source = dataSourceId
            }
        };

        await events.Map.AddLayerAsync(layer);
    }
}

Removing geometries

Geometries can be removed from the data source using the RemoveAsync method.

Clear the data source

The data source can be cleared using the ClearAsync method. This will remove all the geometries from the data source.