Using arbitrary Leaflet plugins with Leaflet for R

README.md

Using arbitrary Leaflet JS plugins with Leaflet for R

The Leaflet JS mapping library has lots of plugins available. The Leaflet package for R provides direct support for some, but far from all, of these plugins, by providing R functions for invoking the plugins.

If you as an R user find yourself wanting to use a Leaflet plugin that isn't directly supported in the R package, you can use the technique shown here to load the plugin yourself and invoke it using JS code.

leaflet-esri.R

library(leaflet)
library(htmltools)
library(htmlwidgets)

# This tells htmlwidgets about our plugin name, version, and
# where to find the script. (There's also a stylesheet argument
# if the plugin comes with CSS files.)
esriPlugin <- htmlDependency("leaflet.esri", "1.0.3",
  src = c(href = "https://cdn.jsdelivr.net/leaflet.esri/1.0.3/"),
  script = "esri-leaflet.js"
)

# A function that takes a plugin htmlDependency object and adds
# it to the map. This ensures that however or whenever the map
# gets rendered, the plugin will be loaded into the browser.
registerPlugin <- function(map, plugin) {
  map$dependencies <- c(map$dependencies, list(plugin))
  map
}


leaflet() %>% setView(-122.23, 37.75, zoom = 10) %>%
  # Register ESRI plugin on this map instance
  registerPlugin(esriPlugin) %>%
  # Add your custom JS logic here. The `this` keyword
  # refers to the Leaflet (JS) map object.
  onRender("function(el, x) {
    L.esri.basemapLayer('Topographic').addTo(this);
  }")

leaflet-heat.R

# This example shows the ability to pass extra R data to onRender.
# At the time of this writing it requires a custom build of htmlwidgets:
# devtools::install_github("ramnathv/htmlwidgets@joe/feature/onrender-data")
#
# Track the progress of this functionality at
# https://github.com/ramnathv/htmlwidgets/pull/202

library(leaflet)
library(htmltools)
library(htmlwidgets)
library(dplyr)

heatPlugin <- htmlDependency("Leaflet.heat", "99.99.99",
  src = c(href = "http://leaflet.github.io/Leaflet.heat/dist/"),
  script = "leaflet-heat.js"
)

registerPlugin <- function(map, plugin) {
  map$dependencies <- c(map$dependencies, list(plugin))
  map
}

leaflet() %>% addTiles() %>%
  fitBounds(min(quakes$long), min(quakes$lat), max(quakes$long), max(quakes$lat)) %>%
  registerPlugin(heatPlugin) %>%
  onRender("function(el, x, data) {
    data = HTMLWidgets.dataframeToD3(data);
    data = data.map(function(val) { return [val.lat, val.long, val.mag*100]; });
    L.heatLayer(data, {radius: 25}).addTo(this);
  }", data = quakes %>% select(lat, long, mag))

I'm trying to use Leaflet.LabelTextCollision, but it doesn't work. What did i miss?

library(tidyverse)
library(leaflet)
library(htmltools)
library(htmlwigets)




label <- data.frame(
lat = c(61.09049, 56.89039, 57.52678, 60.74516, 56.92379, 64.54302, 56.25897, 56.49648, 56.27996, 56.74812, 59.93873, 56.77972, 56.85867, 60.08370, 56.25897),
lon = c(43.17148, 32.65250,  38.31669, 42.04732, 32.74461, 40.53712, 32.08586, 31.64108, 31.66774, 33.51162, 30.31623, 31.25263, 35.92083, 30.27957, 32.08586),
name_label = c("label_1", "label_2", "label_1000", "label_10000", "label_70000", "label_8", "label_999999", "label_777", "label_888888", "label_888", "label_999", "label_7", "label_9", "label_777777777", "label_999999999")
)




col_Plugin <- htmlDependency(
  "Leaflet.LabelTextCollision", "1.4.0",
  src = "./Leaflet.LabelTextCollision-master/dist",
  script = "L.LabelTextCollision.js"
)


registerPlugin <- function(map, plugin) {
  map$dependencies <- c(map$dependencies, list(plugin))
  map
}  


leaflet() %>%
  
  setView(35, 55, zoom = 4) %>%
  
  addProviderTiles(provider =  "OpenStreetMap") %>%
  
  registerPlugin(col_Plugin) %>%

  addLabelOnlyMarkers(lng = label$lon,
                      lat = label$lat,
                      label = lapply(label$name_label, HTML),
                      labelOptions = labelOptions(noHide = T,
                                                  textOnly = F,
                                                  direction = "top")
  ) %>% 
  
  onRender("function(el, x) {

  L.LabelTextCollision().addTo(this);}"

  )