# Author: Egge-Jan Polle - 2 November 2015 - http://www.twiav.nl/
# A short tutorial on using the leaflet package to show multiple map layers in the RStudio Viewer pane
# load the required packages
library(sp)
library(rgdal)
library(leaflet)

# create and set a working directory
dir.create("./RTutorial")
setwd("./RTutorial")

# create a subfolder in the worikng directory to store your data 
dir.create("./Data")

# download and unzip the Municipalities dataset
URL <- "http://www.twiav.nl/files/NL_Municipalities2014.zip"
download.file(URL, destfile ="./Data/NL_Municipalities2014.zip", mode = "wb")
unzip("./Data/NL_Municipalities2014.zip", exdir = "./Data")
unlink("./Data/NL_Municipalities2014.zip") # delete zip file

# download and unzip the Railway and Stations datasets
URL <- "http://www.twiav.nl/files/NL_RailwaysAndStations2015.zip"
download.file(URL, destfile ="./Data/NL_RailwaysAndStations2015.zip", mode = "wb")
unzip("./Data/NL_RailwaysAndStations2015.zip", exdir = "./Data")
unlink("./Data/NL_RailwaysAndStations2015.zip") # delete zip file
rm(URL)

# read the data
nlMun2014 <- readOGR("Data/NL_Municipalities2014.TAB", "NL_Municipalities2014")
nlStations2015 <- readOGR("Data/NL_Stations2015.TAB", "NL_Stations2015")
nlRailways2015 <- readOGR("Data/NL_Railways2015.TAB", "NL_Railways2015")

# have a quick look at the data (optional)
View(nlMun2014)
View(nlStations2015)
View(nlRailways2015)
plot(nlMun2014)
plot(nlStations2015, add=TRUE)
plot(nlRailways2015, add=TRUE)

# reproject the data to wgs84
nlRailways2015_wgs84 <- spTransform(nlRailways2015, CRS("+init=epsg:4326"))
nlStations2015_wgs84 <- spTransform(nlStations2015, CRS("+init=epsg:4326"))
nlMun2014_wgs84 <- spTransform(nlMun2014, CRS("+init=epsg:4326"))

# create popups
station_popup <- paste0("<table><tr><td bgcolor=#E0E0E0><strong>Station: </strong></td><td><a href=",nlStations2015_wgs84$Wikipedia,">",nlStations2015_wgs84$Station,"</a></td></tr></table>")
railway_popup <- paste0("<table><tr><td bgcolor=#E0E0E0><strong>Route: </strong></td><td>",nlRailways2015_wgs84$Route,"</td></tr><tr><td bgcolor=#E0E0E0><strong>Operator: </strong></td><td>",nlRailways2015_wgs84$Operator,"</td></tr></table>")
mun_popup <- paste0("<table><tr><td bgcolor=#E0E0E0><strong>Name: </strong></td><td>",nlMun2014_wgs84$Name,"</td></tr><tr><td bgcolor=#E0E0E0><strong>Province: </strong></td><td>",nlMun2014_wgs84$Province_name,"</td></tr><tr><td bgcolor=#E0E0E0><strong>Inhabitants: </strong></td><td>",format(nlMun2014_wgs84$Inhabitants, big.mark = ".", decimal.mark = ","),"</td></tr></table>")

# create the interactive map
imap <- leaflet() %>%
  # Base groups
  addTiles(group = "Openstreetmap") %>%
  addProviderTiles("Stamen.TonerLite", group = "Stamen Toner Lite") %>%
  addProviderTiles("Stamen.Watercolor", group = "Stamen Watercolor") %>%
  setView(lng = 4.9, lat = 52.378333, zoom = 12) %>% # Amsterdam Centraal Railway Station
  # Overlay groups
  addPolygons(
    data=nlMun2014_wgs84,
    group = "Municipalities (2014)",
    popup = mun_popup,
    fillOpacity = 0,
    color = "#900000",
    weight = 2
  ) %>%
  addPolylines(
    data=nlRailways2015_wgs84,
    group = "Railways",
    popup = railway_popup,
    opacity = 1
  ) %>%
  addCircles(
    data=nlStations2015_wgs84,
    group = "Stations",
    popup = station_popup,
    weight = 3,
    radius=80,
    color="#FF0000",
    stroke = TRUE,
    fillOpacity = 0.8
  ) %>%
  # Layers control
  addLayersControl(
    baseGroups = c("Openstreetmap", "Stamen Toner Lite", "Stamen Watercolor"),
    overlayGroups = c("Stations", "Railways", "Municipalities (2014)"),
    options = layersControlOptions(collapsed = FALSE)
  )
# show the interactive map
imap