GoogleMaps.AspNetCore.Clustering

C# library for clustering map points for AspNetCore 2.1

Original Lib
This is a fork of GoogleMaps.Net.Clustering repo. The project was no longer powered since December 8, 2016 and incompatible with dotnetcore.

Installation

You can download the GoogleMaps.AspNetCore.Clustering package to install the latest version of GoogleMaps.AspNetCore.Clustering Lib.

Usage

First, configure Startup.cs class:

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }
    
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        ...
        app.UseGmc(Configuration.GetSection("GoogleMapsNetClustering"));
        ...
    }
}

You will also need to add the following section to your appsettings.json file.

"GoogleMapsNetClustering": {
    "DoShowGridLinesInGoogleMap": false,
    "OuterGridExtend": 0,
    "DoUpdateAllCentroidsToNearestContainingPoint": false,
    "DoMergeGridIfCentroidsAreCloseToEachOther": true,
    "CacheServices": true,
    "MergeWithin": 2.9,
    "MinClusterSize": 2,
    "MaxMarkersReturned": 500,
    "AlwaysClusteringEnabledWhenZoomLevelLess": 2,
    "ZoomlevelClusterStop": 15,
    "GridX": 6,
    "GridY": 5,
    "MarkerTypes": [1,2,3],
    "MaxPointsInCache": 100000000
  },

Next, this is an example of how to used cached clustering.

public IList<MapPoint> GetClusters(YourFilterObj filter)
{
    string clusterPointsCacheKey = "somecachekey";
    PointCollection points = GetClusterPointCollection(clusterPointsCacheKey);

    ClusterService mapService = new ClusterService(points);
    GetMarkersParams markersParams = new GetMarkersParams()
    {
        NorthEastLatitude = filter.NorthEastLatitude,
        NorthEastLongitude = filter.NorthEastLongitude,
        SouthWestLatitude = filter.SouthWestLatitude,
        SouthWestLongitude = filter.SouthWestLongitude,
        ZoomLevel = filter.ZoomLevel,
        PointType = clusterPointsCacheKey
    };

    ClusterMarkersResponse markers = mapService.GetClusterMarkers(input);

    return markers.Markers;
}

private PointCollection GetClusterPointCollection(string clusterPointsCacheKey)
{
    PointCollection points = new PointCollection();
    if (points.Exists(clusterPointsCacheKey))
        return points;

    var dbPoints = GetPoints(); // Get your points here
    List<MapPoint> points = dbPoints.Select(p => new MapPoint() { X = p.X, Y = p.Y }).ToList();
    TimeSpan cacheDuration = TimeSpan.FromHours(6);
    points.Set(points, cacheDuration, clusterPointsCacheKey);

    return points;
}