wmslegend show/hide on layer/group-add/remove, add group arg

R/wms-legend.R

@@ -8,10 +8,8 @@ wms.legendDependency <- function() {
 
 #' Add WMS Legend
 #' @description Add a WMS Legend
-#' @param map The leaflet map
 #' @param uri The legend URI
-#' @param position position of control: "topleft", "topright", "bottomleft", or "bottomright"
-#' @param layerId A unique ID for the Legend
+#' @inheritParams leaflet:.addLegend
 #' @rdname wms-legend
 #' @export
 #' @examples
@@ -30,10 +28,11 @@ wms.legendDependency <- function() {
 #'       "format=image/png&layer=Personenschaden_5000"
 #'     )
 #'   )
-addWMSLegend <- function(map, uri, position = "topright", layerId = NULL) {
+addWMSLegend <- function(map, uri, position = "topright", layerId = NULL, group = NULL) {
   map$dependencies <- c(map$dependencies, wms.legendDependency())
   options <- leaflet::filterNULL(list(
     layerId = layerId,
+    group = group,
     options = list(uri = uri, position = position)
   ))
 

inst/htmlwidgets/bindings/lfx-wms-legend-bindings.js

@@ -3,10 +3,36 @@ LeafletWidget.methods.addWMSLegend = function(options) {
   (function() {
     var map = this;
     var wmsLegendControl = new L.Control.WMSLegend(options.options);
-    if (options.layerId) {
-      map.controls.add(wmsLegendControl, options.layerId);
-    } else {
-      map.controls.add(wmsLegendControl);
+
+    if (options.group) {
+      // Auto generate a layerID if not provided
+      if(!options.layerId) {
+        options.layerId = L.Util.stamp(wmsLegendControl);
+      }
+
+      map.on("overlayadd", function(e){
+        if(e.name === options.group) {
+          map.controls.add(wmsLegendControl, options.layerId);
+        }
+      });
+      map.on("overlayremove", function(e){
+        if(e.name === options.group) {
+          map.controls.remove(options.layerId);
+        }
+      });
+      map.on("groupadd", function(e){
+        if(e.name === options.group) {
+          map.controls.add(wmsLegendControl, options.layerId);
+        }
+      });
+      map.on("groupremove", function(e){
+        if(e.name === options.group) {
+          map.controls.remove(options.layerId);
+        }
+      });
     }
+
+    map.controls.add(wmsLegendControl, options.layerId);
+
   }).call(this);
 };