Displaying several data rows in popup using Leaflet for R?

Question

While trying to map some quantitative data with leafletin R, I manage to place pie-charts with leaflet.minichartson the map, like in the following example:

### data ###
d <- structure(list(
   area_name = c("Alscheid", "Alzingen", "Angelsberg", "Angelsberg", "Angelsberg", "Arsdorf","Asselborn", "Asselborn", "Baastenduerf", "Bartringen"), 
   surveyID1 = c(1510L, 24L, 382L, 1429L, 1061L, 526L, 1524L, 1281L, 2169L, 1292L), 
   Alter = c("25 bis 34", "25 bis 34", "15 bis 24", "15 bis 24", "25 bis 34", "15 bis 24", "35 bis 44", "35 bis 44", "25 bis 34", "25 bis 34"), 
   latitude = c(49.970094, 49.56885, 49.76374, 49.76374, 49.76374, 49.860547, 50.09624, 50.09624, 49.891134, 49.6038), longitude = c(6.007703, 6.16394, 6.1592, 6.1592, 6.1592, 5.842195, 5.97425, 5.97425, 6.164145, 6.0782), 
   count_all_variants = c(1, 1, 3, 3, 3, 1, 2, 2, 1, 1), 
   var1 = c(1L, 1L, 2L, 3L, 3L, 1L, NA, NA, NA, 1L), 
   var2 = c(NA, NA, 1L, NA, NA, NA, NA, NA, 1L, NA), 
   var3 = c(NA, NA, NA, NA, NA, NA, 2L, 2L, NA, NA)), 
   row.names = c(NA, 10L), class = "data.frame")

### mapping ###
library(leaflet)
library(leaflet.minicharts)

tilesURL <- "http://server.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Light_Gray_Base/MapServer/tile/{z}/{y}/{x}"

title <- tags$div(HTML('<h3>Fussball</h3>'))  
basemap <- leaflet(options = leafletOptions(zoomControl = FALSE, minZoom = 9, maxZoom = 10, dragging = T)) %>%
   addTiles(tilesURL) %>%
   fitBounds(6.1, 49.4426671413, 6.1, 50.1280516628) %>%  
   addControl(title, position = "topleft")

colors <- c('#7fc97f','#beaed4','#fdc086')

basemap %>%
   addMinicharts(
   d$longitude, d$latitude,
   type = "pie",
   chartdata = d[, c("var1", "var2", "var3")], 
   colorPalette = colors,
   popup=popupArgs(
   labels=c("Fussball", "Futtball", "Foussball"),
   html=paste0("<h3>", d$area_name, "</h3>",
               "ID: ", d$surveyID1, "<br>",
               "Alter: ", d$Alter
               )
   ),
   width = 60 * sqrt(d$count_all_variants) / sqrt(max(d$count_all_variants)), transitionTime = 0
)

Working example

In addition to that, I also would like to populate the popup window for each piechart with all the data for the respective location. For the moment, only one data row is displayed, showing 'area_name', 'surveyID1' and 'Alter'. Taking the location 'Angelsberg' as an example (in the middle of the map), I want the popup showing the data for all (3) data rows, which make up the piechart, i.e.:

<h3>Angelsberg</h3>
ID: 382 Alter: 15 bis 24<br>
ID: 1061 Alter: 15 bis 24<br>
ID: 526 Alter: 25 bis 34<br>

I assume that I have to pass some kind of list/array to html but I have no clue how to achieve this here.

Answer 1

First, I think it's a conceptual problem because you have repeated points with different data in the same location, e.g .: Angelsberg and Asselborn locations. So the popup from addMinicharts function will show you n pie charts in the same location, maybe one above the other. So, when you click on the pie chart you can only get the most upper layer.

Briefly, I followed these steps:

1. Add shiny library to use the tag element
2. Transform the data: combine all the available data in each location/point
3. Please check that I execute the mean function to aggregate the data in var1, var2 and var3. I don't know if doing this was correct because that depends in the nature of your data.

Check the commented and reproducible code below.

### data ###
d <- structure(
  list(
    area_name = c(
      "Alscheid",
      "Alzingen",
      "Angelsberg",
      "Angelsberg",
      "Angelsberg",
      "Arsdorf",
      "Asselborn",
      "Asselborn",
      "Baastenduerf",
      "Bartringen"
    ),
    surveyID1 = c(1510L, 24L, 382L, 1429L, 1061L, 526L, 1524L, 1281L, 2169L, 1292L),
    Alter = c(
      "25 bis 34",
      "25 bis 34",
      "15 bis 24",
      "15 bis 24",
      "25 bis 34",
      "15 bis 24",
      "35 bis 44",
      "35 bis 44",
      "25 bis 34",
      "25 bis 34"
    ),
    latitude = c(
      49.970094,
      49.56885,
      49.76374,
      49.76374,
      49.76374,
      49.860547,
      50.09624,
      50.09624,
      49.891134,
      49.6038
    ),
    longitude = c(
      6.007703,
      6.16394,
      6.1592,
      6.1592,
      6.1592,
      5.842195,
      5.97425,
      5.97425,
      6.164145,
      6.0782
    ),
    count_all_variants = c(1, 1, 3, 3, 3, 1, 2, 2, 1, 1),
    var1 = c(1L, 1L, 2L, 3L, 3L, 1L, NA, NA, NA, 1L),
    var2 = c(NA, NA, 1L, NA, NA, NA, NA, NA, 1L, NA),
    var3 = c(NA, NA, NA, NA, NA, NA, 2L, 2L, NA, NA)
  ),
  row.names = c(NA, 10L),
  class = "data.frame"
)


# Transform data

# Load simple features object management library
library(sf)

# Convert to simple feature collection object (points)
d2 <- st_as_sf(d, coords = c("longitude", "latitude"))

# Get intersection of the same object
d3 <- st_intersection(d2)

# See origins columns (which elements intersects)
d3$origins

list <- lapply(1:length(d3$origins), function(x) {
  point <- d3[x, ]
  point$surveyID1 <-
    stringr::str_flatten(d2[d3$origins[[x]], ]$surveyID1, collapse = ", ")
  point$Alter <-
    stringr::str_flatten(d2[d3$origins[[x]], ]$Alter, collapse = ", ")
  point$var1 <- mean(d2[d3$origins[[x]], ]$var1, na.rm = TRUE)
  point$var2 <- mean(d2[d3$origins[[x]], ]$var2, na.rm = TRUE)
  point$var3 <- mean(d2[d3$origins[[x]], ]$var3, na.rm = TRUE)

  return(point)

})

# Bind list points
new_d <- do.call(rbind, list)
print(class(new_d)) # simple features object

# Add lat and long data as columns
new_d$longitude <- st_coordinates(new_d)[, "X"]
new_d$latitude <- st_coordinates(new_d)[, "Y"]

# Transform to data frame adding null to geometries
st_geometry(new_d) <- NULL
print(class(new_d))

### mapping ###
library(leaflet)
library(leaflet.minicharts)

tilesURL <-
  "http://server.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Light_Gray_Base/MapServer/tile/{z}/{y}/{x}"

title <-
  shiny::tags$div(HTML('<h3>Fussball</h3>')) # add shiny library to use "tags"
basemap <-
  leaflet(options = leafletOptions(
    zoomControl = FALSE,
    minZoom = 9,
    maxZoom = 10,
    dragging = T
  )) %>%
  addTiles(tilesURL) %>%
  fitBounds(6.1, 49.4426671413, 6.1, 50.1280516628) %>%
  addControl(title, position = "topleft")

colors <- c('#7fc97f', '#beaed4', '#fdc086')

basemap %>%
  addMinicharts(
    new_d$longitude,
    new_d$latitude,
    type = "pie",
    chartdata = new_d[, c("var1", "var2", "var3")],
    colorPalette = colors,
    popup = popupArgs(
      labels = c("Fussball", "Futtball", "Foussball"),
      html = paste0(
        "<div>",
        "<h3>",
        new_d$area_name,
        "</h3>",
        "ID: ",
        new_d$surveyID1,
        "<br>",
        "Alter: ",
        new_d$Alter,
        "</div>"
      )
    ),
    width = 60 * sqrt(new_d$count_all_variants) / sqrt(max(new_d$count_all_variants)),
    transitionTime = 0
  )