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How do you loop through a SharedData object in order to plot separate addPolylines to a Leaflet map in R?

I have dataset with distinct "routes", and I add them one by one in a for loop to not make them connected with each other. Next, I want them all to be responsive to a slider added by the Crosstalk package, but I am having issues looping through the SharedData$new object.

I have tried:

#Load libraries
library(dplyr); library(leaflet)


# An example of my data:
data <- data.frame(lon = c(12.42111, 12.42111, 12.41170, 12.42111, 12.39508, 12.39970, 12.42111, 12.39508),
                   lat = c(55.73615, 55.73615, 55.74155, 55.73615, 55.73074, 55.73871, 55.73615, 55.73074),
                   date = c("2020-03-28 12:46:29", "2020-03-28 13:20:42", "2020-03-28 13:50:47", "2020-03-28 18:33:44",
                            "2020-03-28 19:24:11", "2020-03-28 20:31:29", "2020-03-28 21:33:29", "2020-03-28 21:42:05"),
                   group = c(1, 1, 1, 1, 2, 2, 2, 2))

data$date <- as.POSIXct(data$date, format="%Y-%m-%d %H:%M:%S")

# Create leaflet map
temp_leaflet <- leaflet(data) %>% addTiles()


# for loop way of adding grouped routes
for (i in unique(factor(data$group))) {
  temp_leaflet <- temp_leaflet %>% 
    addPolylines(data = data[data$group == i, ],
                 lng = ~lon, lat = ~lat, group = i)
}


temp_leaflet <- temp_leaflet %>%
  hideGroup(unique(factor(data$group))) %>% 
  
  addLayersControl(
    overlayGroups = unique(factor(data$group)),
    options = layersControlOptions(collapsed = F))

So this is way I do it, but if I want to be able to change the two routes by time in a slider (date column) with the Crosstalk package, I simply can't figure out how to loop through a SharedData$new object, and group it, so that it is hidden by default.

Any thoughts on how to achieve this end?

Soren
  • 17
  • 3

0 Answers0