Show zoomed section in Elevation profile control

In this example, we will showcase a scenario where we focus on a particular portion of the elevation profile and emphasize that specific section on the map. By utilizing the onChangeView event of the elevation profile control for MapTiler SDK, we are able to retrieve a GeoJSON LineString that corresponds to the zoomed-in segment. Consequently, we can exhibit the selected section on the map alongside the entire route.

^{Zoom in on a profile section to highlight that section on the map.}

1. Install the npm package.

npm install --save @maptiler/sdk @maptiler/elevation-profile-control

1. Create the map style. Add the map style to your stylesheet. The div must have non-zero height.

    body { 
      margin: 0;
      padding: 0;
    }
    
    #map {
        position: absolute;
        top: 0;
        bottom: 0;
        width: 100%;
    }
    

1. Create a <div> element with a certain id where you want your map to be.

   Add <div> tag into your page. This div will be the container where the map will be loaded.

<div id="map"></div>

1. Include the CSS file.

   If you have a bundler that can handle CSS, you can import the CSS from @maptiler/sdk/dist/maptiler-sdk.css.

import '@maptiler/sdk/dist/maptiler-sdk.css';

<div class="markdown-alert markdown-alert-note" markdown="1">
<p class="markdown-alert-title">Note</p>
Including the CSS file using a `<link>` in the head of the document via the CDN is the easiest way.


<pre class="language-html" style="position: relative;" markdown="0"><code class="language-html">
&lt;link href=&#39;https://cdn.maptiler.com/maptiler-sdk-js/v4.1.0/maptiler-sdk.css&#39; rel=&#39;stylesheet&#39; /&gt; </code></pre>


</div>

1. Load the map with the style. Include the following code in your JavaScript.

    import { config, Map, helpers, MapStyle } from '@maptiler/sdk';
    
    config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
    const map = new Map({
        container: 'map', // container's id or the HTML element in which SDK will render the map
        style: MapStyle.OUTDOOR,
        center: [1.71593, 42.2216], // starting position [lng, lat]
        zoom: 12.51 // starting zoom
    });
    

1. Replace YOUR_MAPTILER_API_KEY_HERE with your own API key. Make sure to secure the key before you publish it.

2. Add a GeoJSON trace to the map. Check out the How to Upload GeoJSON to MapTiler tutorial. Download the Pedraforca hiking sample data

map.on('load', async () => {

      helpers.addPolyline(map, {
        data: './loop_track.geojson', //from a URL or a MapTiler Data UUID
        lineColor: "#008", 
        outline: true, 
        outlineWidth: 1.5
      });
      //Layer to display the zoomed section of the route
      const layerInfo2 = await helpers.addPolyline(map, {
        data: './loop_track.geojson', //from a URL or a MapTiler Data UUID
        lineColor: "#f00", 
        outline: true, 
        outlineWidth: 1.5
      });

    });

1. Import the MapTiler elevation profile control

import { ElevationProfileControl } from "@maptiler/elevation-profile-control";

1. Instantiate the control and add it to a Map instance, most likely inside a map "load" event callback

map.on('load', () => {

      helpers.addPolyline(map, {
        data: './loop_track.geojson', //from a URL or a MapTiler Data UUID
        lineColor: "#008", 
        outline: true, 
        outlineWidth: 1.5
      });
      //Layer to display the zoomed section of the route
      const layerInfo2 = await helpers.addPolyline(map, {
        data: './loop_track.geojson', //from a URL or a MapTiler Data UUID
        lineColor: "#f00", 
        outline: true, 
        outlineWidth: 1.5
      });

      // Create an instance (with the onChangeView event listener)
      const epc = new ElevationProfileControl({
        onChangeView: (route) => {
          map.getSource(layerInfo2.polylineSourceId).setData(route);
        }
      });

      // Add it to your map
      map.addControl(epc);

      // Add some data (from a URL or a MapTiler Data UUID)
      epc.setData('./loop_track.geojson');

    });

import '@maptiler/sdk/dist/maptiler-sdk.css';
import { config, Map, helpers, MapStyle } from '@maptiler/sdk';
import { ElevationProfileControl } from "@maptiler/elevation-profile-control";

config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';

const map = new Map({ 
  container: 'map', // container's id or the HTML element in which SDK will render the map
  center: [1.71593, 42.2216],
  zoom: 12.51,
  style: MapStyle.OUTDOOR
});

map.on('load', async () => {

  helpers.addPolyline(map, {
    data: './loop_track.geojson', //from a URL or a MapTiler Data UUID
    lineColor: "#008", 
    outline: true, 
    outlineWidth: 1.5
  });
  //Layer to display the zoomed section of the route
  const layerInfo2 = await helpers.addPolyline(map, {
    data: './loop_track.geojson', //from a URL or a MapTiler Data UUID
    lineColor: "#f00", 
    outline: true, 
    outlineWidth: 1.5
  });

  // Create an instance (with the onChangeView event listener)
  const epc = new ElevationProfileControl({
    visible: true,
    onChangeView: (route) => {
      map.getSource(layerInfo2.polylineSourceId).setData(route);
    }
  });

  // Add it to your map
  map.addControl(epc);

  // Add some data (from a URL or a MapTiler Data UUID)
  epc.setData('./loop_track.geojson');

});

Learn more

You can also use elevation control via CDN. See the Elevation profile control example to use it as a CDN instead of an NPM module.

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