ekalaya/Leaflet.FeatureGroup.SubGroup

Creates a Feature Group that adds its child layers into a parent group when added to a map (e.g. through L.Control.Layers)

Leaflet.FeatureGroup.SubGroup

Creates a Leaflet Feature Group that adds its child layers into a parent group when added to a map (e.g. through L.Control.Layers).

Typical usage is to dynamically add/remove groups of markers from Marker Cluster.

Leaflet.markercluster plugin provides beautiful animated Marker Clustering functionality.

Leaflet is the leading open-source JavaScript library for mobile-friendly interactive maps.

Size: 2 kB minified, < 1 kB gzipped.

Requirements

Requires Leaflet ^1.0.0

For Leaflet ~0.7.7 use the v0.1.2 release or the leaflet-0.7 branch

Optional: Leaflet.markercluster plugin

Demos

• SubGroup with standard L.Control.Layers and MarkerCluster
• SubGroup with standard L.Control.Layers to display Nested Groups

Usage instructions

Quick Guide

HTML:

<!-- after Leaflet script -->
<script src="leaflet.featuregroup.subgroup.js"></script>

JavaScript:

var map = L.map("map"),
    parentGroup = L.markerClusterGroup(options), // Could be any other Layer Group type.

    // This is where the magic happens!
    mySubGroup = L.featureGroup.subGroup(parentGroup, arrayOfMarkers);

parentGroup.addTo(map);
mySubGroup.addTo(map);

Now adding the sub-group to the map adds clustered markers!

It should virtually be compatible with any LayerGroup plugin, not only MarkerCluster.

Installing the sub-plugin

Local copy

1. Download the "leaflet.featuregroup.subgroup.js" file from the v1.0.2 release.
2. Place the file alongside your page.
3. Add the script tag (see Quick Guide > HTML) to your page after Leaflet script.

CDN

You can alternatively use the free unpkg CDN service, but keep in mind that it "is a free, best-effort service and cannot provide any uptime or support guarantees".

<!-- After Leaflet script -->
<script src="https://unpkg.com/leaflet.featuregroup.subgroup@1.0.2/dist/leaflet.featuregroup.subgroup.js"></script>

npm

1. Add this package to your project:

   $ npm install leaflet.featuregroup.subgroup --save

2. If you are using a bundling tool, import in your JavaScript. It only performs the side effect of attaching to the global L namespace, so you do not need to store it into a local variable or import a namespace.

   require('leaflet.featuregroup.subgroup');
   // Or with ES6:
   import 'leaflet.featuregroup.subgroup';

Creation

Simply use the L.featureGroup.subGroup factory instead of your regular L.featureGroup or L.layerGroup:

var mySubGroup = L.featureGroup.subGroup(parentGroup);

mySubGroup.addTo(map);

Do not forget to add the parent group to your map.

API Reference

Creation

Factory	Description
L.featureGroup.subGroup( <ILayer> parentGroup?, <ILayer[]> layersArray? )	Creates a sub-group with events, optionally given a parent group and an initial array of child layers.

Methods

Method	Returns	Description
setParentGroup( <ILayer> parentGroup )	this	Changes the parent group into which child markers are added to / removed from.
setParentGroupSafe( <ILayer> parentGroup )	this	Removes the current sub-group from map before changing the parent group. Re-adds the sub-group to map if it was before changing.
getParentGroup()	<ILayer>	Returns the current parent group.

SubGroup does not provide any extra option or event beyond what L.LayerGroup and L.FeatureGroup already provide.

Limitations

If you change the parent group while the sub-group and/or its child markers are still on map, unexpected behaviour of the previous and/or new parent groups can happen.

Make sure the sub-group and its child layers are removed from map before changing the parent group, or use the setParentGroupSafe method instead.

License

Leaflet.FeatureGroup.SubGroup is distributed under the BSD 2-clause "Simplified" License, like Leaflet.