Get the sf data frame of a clicked feature from the map widget

The click input is a list containing the layerId, properties, geometry, and time. Turn this into an sf object.

Usage

get_clicked_feature(clicked_feature_input)

Arguments

clicked_feature_input

A list representing the clicked feature.

Value

A sf object representing the clicked feature, or NULL.

Details

To get the clicked feature, use input$map_feature_click in a Shiny app, where map is the ID of your map output. This input will contain a list representing the clicked feature whenever a feature is clicked on the map. Pass this input to get_clicked_feature() to convert it into an sf object for easier manipulation in R.

Note

time is not used in this function, but it is included in the input so that the same feature can be clicked multiple times and the changed time means that the input will be updated.

Examples

if(interactive()){
library(shiny)
library(spData)
library(sf)
library(toro)

nz_data <- spData::nz_height |>
  sf::st_transform(4326)

ui <- fluidPage(
 tagList(
   mapOutput("map")
 )
)
server <- function(input, output, session) {
 output$map <- renderMap({
   map() |>
     set_bounds(bounds = nz_data) |>
     add_circle_layer(
       id = "nz_elevation",
       source = nz_data
     )
 })

 # Print the clicked feature as an sf object
 observe({
   req(input$map_loaded, input$map_feature_click)
   print(get_clicked_feature(input$map_feature_click))
 }) |>
   bindEvent(input$map_feature_click)
}
}