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Shapes

This help article demonstrates how to bind, display and customize shapes with RadMap from JSON files in GeoJSON format.

Shape Layer Overview

For displaying shapes in a RadMap layer, the Type property of the MapLayer should be set to Shape:

ASP.NET
<telerik:RadMap RenderMode="Lightweight" runat="server" ID="RadMap1">
	<LayersCollection>
		<telerik:MapLayer Type="Shape"></telerik:MapLayer>
	</LayersCollection>
</telerik:RadMap>

For binding GeoJSON data to a Shape layer, the ClientDataSourceID property of the MapLayer should be set to a properly configured RadClientDataSource control, where the data could be retrieved from a local file or a web service. Following is a simple example demonstrating such configuration:

ASP.NET
<telerik:RadClientDataSource runat="server" ID="RadClientDataSource1">
	 <DataSource>
		  <WebServiceDataSourceSettings ServiceType="GeoJSON">
			   <Select Url="Content/countries.json" DataType="JSON" />
		  </WebServiceDataSourceSettings>
	 </DataSource>
</telerik:RadClientDataSource>
	
<telerik:RadMap RenderMode="Lightweight" runat="server" ID="RadMap1">
	 <LayersCollection>
		  <telerik:MapLayer ClientDataSourceID="RadClientDataSource1" Type="Shape"></telerik:MapLayer>
	 </LayersCollection>
</telerik:RadMap>

An online demo for binding to local JSON file with RadClientDataSource, where the countries.json files from the above example could be downloaded, is available at the following link: RadMap – Shapes Layer.

Customizing Shapes

RadMap allows you to customize all shapes in a layer by setting the MapLayer’s StyleSettings and the FillSettings and StrokeSettings in particular. The FillSettings could be used for setting the fill Color and Opacity of the shapes, where the StrokeSettings could specify Color, Opacity, Width and DashType.

In scenarios, where each shape in a layer should be styled differently, all of the above fill and stroke settings could be set in any of the client-side events, where the shape is available as an argument.

Following is an example for handling the client-side OnShapeCreated event and changing some fill and stroke properties of the shape:

ASP.NET
<telerik:RadClientDataSource runat="server" ID="RadClientDataSource1">
	<DataSource>
		<WebServiceDataSourceSettings ServiceType="GeoJSON">
			<Select Url="Content/countries.json" DataType="JSON" />
		</WebServiceDataSourceSettings>
	</DataSource>
</telerik:RadClientDataSource>

<telerik:RadMap RenderMode="Lightweight" runat="server" ID="RadMap1" Width="800px" Height="500px">
	<LayersCollection>
		<telerik:MapLayer ClientDataSourceID="RadClientDataSource1" Type="Shape"></telerik:MapLayer>
	</LayersCollection>
	<ClientEvents OnShapeCreated="shapeCreated" />
</telerik:RadMap>

<script type="text/javascript">
	function shapeCreated(e) {
		e.shape.options.set("fill.color", "#999999");
		e.shape.options.set("stroke.color", "#555555");
		e.shape.options.set("stroke.width", "2");
	}
</script>

GeoJSON specifics in the context of RadMap

RadMap supports all Geometry and Feature Objects, as well as the Geometry and Feature Collections from the GeoJSON Specification (which could be found at https://geojson.org).

One thing to have in mind, when working with Point objects, is that by default, each Point object in the Shape layer is automatically converted to a Marker. For preventing this behavior, the client-side OnMarkerCreated event should be canceled, which will generate a Circle object instead of a marker.

The Circle objects then could be customized within the client-side OnShapeCreated event, where the radius could be altered. Following is a simple example for such implementation:

ASP.NET
<telerik:RadClientDataSource runat="server" ID="RadClientDataSource1">
	<DataSource>
		<WebServiceDataSourceSettings ServiceType="GeoJSON">
			<Select Url="Content/points.json" DataType="JSON" />
		</WebServiceDataSourceSettings>
	</DataSource>
</telerik:RadClientDataSource>

<telerik:RadMap RenderMode="Lightweight" runat="server" ID="RadMap1" Width="800px" Height="500px">
	<LayersCollection>
		<telerik:MapLayer ClientDataSourceID="RadClientDataSource1" Type="Shape"></telerik:MapLayer>
	</LayersCollection>
	<ClientEvents OnMarkerCreated="markerCreated" OnShapeCreated="shapeCreated"/>
</telerik:RadMap>

<script type="text/javascript">
	//Preventing the Point objects to be represented as markers.
	function markerCreated(e) {
		e.preventDefault();
		//Circle object will be generated instead of the marker
	}

	//Customizing the Circle
	function shapeCreated(e) {
		//the radius will be available for altering only for Circle objects
		if (e.shape._geometry && e.shape._geometry.setRadius) {
			e.shape.options.set("stroke.color", "#999999");
			e.shape.options.set("fill.color", "#666666");
			e.shape._geometry.setRadius(10);
		}
	}
</script>

See Also