Custom mouseover on a layer

The mouseover is a popup window that is displayed after clicking on features on the map.

If no mouseover content is set in the layer configuration, no popup is displayed when clicking on a feature of that layer.

You can set your own mouseover content programatically in Javascript. For instance, you can add a mouseover on a layer that has no mousoever content in its configuration.

In the following example, the layer “Hydrography”, id=3, has no mouseover defined.

We will set a custom mouseover content that:

Always displays a custom header
Displays the mouseover content for a clicked hydrography feature
Avoids displaying a mouseover for the “Event” layer (blue dots on the map)
Always displays a custom footer

Set the custom mouseover

Show example in Codepen.io

Click on the water to see hydrography mouseover.

The code:

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <meta charset="UTF-8">
    <style>
      #my-custom-map {
        width: 600px;
        height: 600px;
        border: 1px solid grey;
      }
    </style>
  </head>
  <body class="jmap_wrapper">
    <div id="my-custom-map"></div>
    <script type="text/javascript">
      const HYDRO_LAYER_ID = 3;
      const PLACE_LAYER_ID = 6;
      window.JMAP_OPTIONS = {
        projectId: 1,
        restBaseUrl: "https://jmapdoc.jmaponline.net/services/rest/v2.0",
        anonymous: true,
        map: {
          containerId: "my-custom-map",
          zoom: 13.797865986918877,
          center: {
            x: -73.48063889179525,
            y: 45.664231577062765
          }
        },
        extensions: [{
          id: "custom-mouseover-extension",
          initFn: () => {
            JMap.Event.MouseOver.on.beforeContentProcessed("My-custom-mouse-over", params => {
              const {
                selection,
                getFeaturesByLayerId,
                addHtmlContentAtTheBeginning,
                addHtmlContentAtTheEnd,
                removeFeaturesFromLayerSelection
              } = params;
              /* this method is processed each time we click on features on the map, even if no mouse-over is defined for a layer */
              /* add a message in the top of the mouseover popup */
              addHtmlContentAtTheBeginning(`<span style="font-size: 1rem">Custom popup header visible for all layers</span>`);
              /* add a message in the bottom of the mouseover popup */
              addHtmlContentAtTheEnd(`<span style="font-size: 1rem">Custom popup footer visible for all layers</span>`);
              console.info("All selected features", { ...selection });
              /* if some place feature has been selected, remove it from the mouseover */
              removeFeaturesFromLayerSelection(PLACE_LAYER_ID, getFeaturesByLayerId(PLACE_LAYER_ID).map(f => f.id));
              console.info("Selected hydrography features", getFeaturesByLayerId(HYDRO_LAYER_ID));
            })
          },
          renderMouseOver: (layer, feature) => {
            /* this method is processed for each feature that has been clicked */
            if (layer.id !== HYDRO_LAYER_ID) {
              return;
            }
            return {
              html: `
                <div style="display: flex; flex-direction: column; align-items: center;">
                  <span>
                    Hydro feature id="${feature.id}" clicked !
                  </span>
                  <button
                    onclick="alert('Feature id=${feature.id} clicked !')"
                    style="cursor: pointer; border: 1px solid grey; margin: .5rem;">
                    Click me !
                  </button>
                </div>`
            };
          }
        }]
      }
    </script>
    <script defer type="text/javascript" src="https://cdn.jsdelivr.net/npm/jmap-core-js@7_Kathmandu_HF3"></script>  
  </body>
</html>