Add setStyle()

Author: cmcaine

NAMESPACE

@@ -155,6 +155,7 @@ export(renderLeaflet)
 export(safeLabel)
 export(scaleBarOptions)
 export(setMaxBounds)
+export(setStyle)
 export(setView)
 export(showGroup)
 export(tileOptions)

R/methods.R

@@ -32,6 +32,26 @@ setView <- function(map, lng, lat, zoom, options = list()) {
   )
 }
 
+#' Efficiently style a group that has already been added to the map
+#'
+#' Call with a group and a vector of style lists of length N. The first N
+#' features of the group will be restyled.
+#'
+#' @examples
+#' \donttest{
+#' renderLeaflet("map", {
+#'   leaflet() %>% addPolygons(data = zones, group = "zones", color = "red")
+#' })
+#' colour = "blue"
+#' styles = lapply(pal(values), function(colour) {list(fillColor=colour, color=colour)})
+#' leafletProxy("map") %>%
+#'   setStyle("zones", styles)
+#' }
+#' @export
+setStyle = function(map, group, styles) {
+    invokeMethod(map, NULL, "setStyle", group, styles)
+}
+
 #' @describeIn map-methods Flys to a given location/zoom-level using smooth pan-zoom.
 #' @export
 flyTo <- function(map, lng, lat, zoom, options = list()) {

inst/htmlwidgets/leaflet.js

@@ -1282,6 +1282,15 @@ function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { de
 var methods = {};
 exports.default = methods;
 
+/** Much more performant way to style loaded geometry */
+
+methods.setStyle = function (group, styles) {
+  window.map = this;
+  var layers = this.layerManager.getLayerGroup(group).getLayers();
+  for (var i = 0; i < styles.length; i++) {
+    layers[i].setStyle(styles[i]);
+  }
+};
 
 function mouseHandler(mapId, layerId, group, eventName, extraInfo) {
   return function (e) {

javascript/src/methods.js

@@ -13,6 +13,14 @@ import Mipmapper from "./mipmapper";
 let methods = {};
 export default methods;
 
+/** Much more performant way to style loaded geometry */
+methods.setStyle = function(group, styles) {
+  window.map = this;
+  let layers = this.layerManager.getLayerGroup(group).getLayers();
+  for (let i = 0; i < styles.length; i++) {
+    layers[i].setStyle(styles[i]);
+  }
+};
 
 function mouseHandler(mapId, layerId, group, eventName, extraInfo) {
   return function(e) {