toro (version 0.1.0)

get_drawn_shape: Get the drawn shape from the map widget

Description

Parses the JSON string returned by the map widget when a shape is drawn. Ensures that the ID of the shape is included in the resulting sf object.

Usage

get_drawn_shape(create_input_string)

Value

A sf object representing the drawn shape, or NULL.

Arguments

create_input_string

A JSON string representing the drawn shape.

Details

To get the drawn shape, use input$map_shape_created in a Shiny app, where map is the ID of your map output. This input will contain a JSON string representing the drawn shape whenever a new shape is created using the draw control on the map. Pass this input to get_drawn_shape() to convert it into an sf object for easier manipulation in R.

Examples

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

ui <- fluidPage(
 tagList(
   mapOutput("map")
 )
)
server <- function(input, output, session) {
 output$map <- renderMap({
   map() |>
    add_draw_control()
 })

 # Update the list of drawn shape IDs when a new shape is created
 observe({
   req(input$map_loaded, input$map_shape_created)
   new_shape <- get_drawn_shape(input$map_shape_created)
   print(new_shape)
 }) |>
   bindEvent(input$map_shape_created)
}
}