How to change a MapView's main data

Question

I'm trying to use observeEvent() to change the Mapview's x argument to new data. I'd normally just use clearShapes() then addPolygons(), but need the zcol etc. arguments.

I'd like to do something similar to the following:

server <- function(input, output) {
  output$DisplayMap <- renderLeaflet(
    mapview(first_data, zcol = coolCol, color = brewer.pal(12, "Set3") %>%
      addControl(actionButton("Next", ">"), position = "topright")
  )
  observeEvent(input$Next, {
    output$DisplayMap$x <- next_data  # This doesn't work
  })
}

I realise there's 2 issues at play (an interface to change the variable and a means to do so), and one of them probably needs React in some form or another

Answer 1

I think it's not possible to modify output like this (but indeed, it will be easier with MRE).

You should think about something like this:

server <- function(input, output) {

  my_data <- reactiveVal(data.frame(a = 1, b = 2))

  output$DisplayMap <- renderLeaflet(
    mapview(my_data()[[input$Next]], zcol = coolCol, color = brewer.pal(12, "Set3") %>%
      addControl(actionButton("Next", ">"), position = "topright")
  )
}

Assuming input$Next is a name of column which user can choose in GUI. This is just to show you an idea. Send MRE if you still need a help and I can edit this answer.