Adding markers using checkbox Leaflet/R - r

Question

I'm trying to add markers on my interactive Leaflet map if the user ticks off a checkbox. However, I can't get the checkbox-appearance to work within the renderLeaflet function, but I can within a renderPlot function.
My code, that works, looks as below:
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
checkboxInput('check1','Show Counties', value = TRUE)),
mainPanel(
# I'm aware that this should be changed to leaftletOutput, when used
# with the in the second code snippet below
plotOutput("mymap")
),
position = 'right'
)
)
server <- function(input, output) {
output$mymap <- renderPlot({
if (input$check1){
hist(rnorm(10))
} else {
hist(rnorm(100))
}
})
}
shinyApp(ui = ui, server = server)
The same logic doesn't work within Leaflet, and I would highly appreciate input on how to modify the below code. I know you don't have access to the two variables, USstates or coor, but I was hoping one could point the error, potentially in terms a syntax error. The output function looks as follows;
output$mymap <- renderLeaflet({
if (input$check1 == TRUE){
leaflet(USstates) %>%
addTiles() %>%
addPolygons(color = 'navy',
opacity = 1.0,
weight = 1) %>%
addMarkers(lng = coor[,1],lat = coor[,2])
} else {
leaflet(USstates) %>%
addTiles() %>%
addPolygons(color = 'navy',
opacity = 1.0,
weight = 1)
}
})

Answer 1

I came up with a solution, of cause right after I created this post. The solution was to wrap the leaflet code in a reactive function and call that one in the renderLeaflet function. The solution is as follows:
server <- function(input, output) {
display <- reactive({
if (input$check1){
leaflet(USstates) %>%
addTiles() %>%
addPolygons(color = 'navy',
opacity = 1.0,
weight = 1) %>%
addMarkers(lng = coor[,1],lat = coor[,2])
} else {
leaflet(USstates) %>%
addTiles() %>%
addPolygons(color = 'navy',
opacity = 1.0,
weight = 1)
}
})
output$mymap <- renderLeaflet({
display()
})
}