Interactive Map and Lat Lon Input Interface in Rshiny

Question

Here's what I tried

server <- function(input, output) {
  observe({
    output$mymap <- renderLeaflet({
      leaflet() %>%
        addTiles() %>%
        fitBounds(-124.7666, 49.4000, -67.0583, 25.0666)%>%
        setView(-95.91245, 37.2333, zoom = 3)
    })
    
    click = input$mymap_click
    if(is.null(click))
      return()
    
    leafletProxy('mymap')%>%addMarkers(lng = click$lng,
                                       lat = click$lat)%>%
      setView(lng = click$lng,
              lat = click$lat, zoom =7)
    
    output$text <- renderText(paste(click$lng,click$lat))
  })
}

ui <- fluidPage(textOutput("text"),
                leafletOutput("mymap"))

shinyApp(ui = ui, server = server)

But instead of a reactive output text, I want something which is dynamic i.e., map should change with change in lat, lon value and vice versa

Here's a sample representation from https://psl.noaa.gov/eddi/

Answer 1

If what you want is for the map to center on the clicked marker, move the lines from click = ... to setView in its own observeEvent(). Also, you do not need to wrap everything in an observe().

server <- function {
  output$mapmap <- renderLeaflet(...)

  observeEvent(input$mymap_click) {
    click = ...
    ...
    leafletProxy(...) %>%
      setView(...)

  }

  output$text <- renderText(...)

}