growstuff/app/assets/javascripts/cropmap.js.erb

function showCropMap(cropmap) {
  L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
    attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
    maxZoom: 18
  }).addTo(cropmap);
  var markers = new L.MarkerClusterGroup({showCoverageOnHover: false, maxClusterRadius: 20 });

  var crop_icon = L.icon({
    iconUrl: location.pathname + '.svg',
    iconSize: [24, 24],
    iconAnchor: [12, 12],
    popupAnchor: [0, -12],
  });

  var things_to_map = location.pathname + '.json';
  $.getJSON(things_to_map, function(crop) {
    $.each(crop.plantings, function(i, planting) {
      var owner = planting.owner;
      if (owner.latitude && owner.longitude) {
        var marker = new L.Marker(new L.LatLng(owner.latitude, owner.longitude),
          {'icon': crop_icon});

        var planting_url = "/plantings/" + planting.id;
        var planting_link = "<a href='" + planting_url + "'>" + owner.login_name + "'s " + crop.name + "</a>";

        var where = "<p><i>" + owner.location + "</i></p>";

        var details = "<p>";
        if (planting.quantity) {
          details = details + "Quantity: " + planting.quantity + "<br/>";
        }
        if (planting.planted_from) {
          details = details + "Planted from: " + planting.planted_from + "<br/>";
        }
        if (planting.sunniness) {
          details = details + "Planted in: " + planting.sunniness+ "<br/>";
        }
        details = details + "</p>";
        marker.bindPopup(planting_link + where + details).openPopup();
        markers.addLayer(marker);
      }
    });
  });

  cropmap.addLayer(markers);
}

$(document).ready(function() {

  if (document.getElementById("cropmap") !== null) {
    L.Icon.Default.imagePath = '/assets';

    var cropmap = L.map('cropmap').setView([0.0, -0.0], 2);
    showCropMap(cropmap);
  }

  $('.btn.toggle.crop-hierarchy').click(function () {
    $('.toggle.crop-hierarchy').toggleClass('hide');
  });
});