R flexdashboard with two simultaneous input$map_shape_click not working - r

Question

I am in the process of creating an R flexdashboard. The dashboard contains several maps for Bangladesh, which are linked to a (Highcharts) chart that is activated by clicking on a polygon (e.g. region). I am able to make it work for one page. However, if I set it up for two pages, things no longer work.
It seems that flexdashboard (at least how I set it up) is not able to handle two input$map_shape_click operations at the same time. At the moment it only works on the first page, while the map does not react on the second page although a figure is produced. I welcome any suggestions to make this work.
Below a reproducible example. Note that (1) I omitted the flexdashboard yaml in the example and (2) markdown used by stackoverflow automatically renders the first, second and third header level. They render differently when run in flexdasboard (i.e. A Large Header is a new page in flexdashboard).
# Packages
library(tidyverse)
library(raster)
library(sf)
library(highcharter)
library(leaflet)
library(htmltools)
# Get data
adm1 <- getData('GADM', country='BGD', level=1)
adm1 <- st_as_sf(adm1)
# Create dummy data.frames with link to polygon
df1 <- data.frame(NAME_1 = adm1$NAME_1,
value_1 = c(1:7))
df2 <- data.frame(NAME_1 = adm1$NAME_1,
value_2 = c(8:14))
Page 1
Column {data-width=350}
Map 1
# MAIN MAP --------------------------------------------------------------------------------
output$map <- renderLeaflet({
# Base map
leaflet() %>%
addTiles(group = "OpenStreetMap") %>%
clearShapes() %>%
addPolygons(data = adm1,
smoothFactor = 0,
color = "black",
opacity = 1,
fillColor = "transparent",
weight = 0.5,
stroke = TRUE,
label = ~htmlEscape(NAME_1),
layerId = ~NAME_1,
)
})
leafletOutput('map')
# REGION SELECTION -----------------------------------------------------------------------
# Click event for the map to draw chart
click_poly <- eventReactive(input$map_shape_click, {
x <- input$map_shape_click
y <- x$id
return(y)
}, ignoreNULL = TRUE)
observe({
req(click_poly()) # do this if click_poly() is not null
# Add the clicked poly and remove when a new one is clicked
map <- leafletProxy('map') %>%
removeShape('NAME_1') %>%
addPolygons(data = adm1[adm1$NAME_1 == click_poly(), ],
fill = FALSE,
weight = 4,
color = '#d01010',
opacity = 1,
layerId = 'NAME_1')
})
Column {data-width=350}
Plot 1
data <- reactive({
# Fetch data for the click poly
out <- df1[df1$NAME_1 == click_poly(), ]
print("page 1") # print statement to show which click_poly is used
return(out)
})
output$plot <- renderHighchart({
req(data()) # do this if click_poly() is not null
chart <- highchart() %>%
hc_chart(type = 'column') %>%
hc_legend(enabled = FALSE) %>%
hc_xAxis(categories = c('A'),
title = list(text = 'Title 1')) %>%
hc_yAxis(title = list(text = 'Value 1')) %>%
hc_plotOptions(series = list(dataLabels = list(enabled = TRUE))) %>%
hc_add_series(name = 'Series',
data = c(data()$value_1)) %>%
hc_add_theme(hc_theme_smpl()) %>%
hc_colors(c('#d01010'))
})
highchartOutput('plot')
Page 2
Column {data-width=350}
Map 2
# MAIN MAP --------------------------------------------------------------------------------
output$map2 <- renderLeaflet({
# Base map
leaflet() %>%
addTiles(group = "OpenStreetMap") %>%
clearShapes() %>%
addPolygons(data = adm1,
smoothFactor = 0,
color = "black",
opacity = 1,
fillColor = "transparent",
weight = 0.5,
stroke = TRUE,
label = ~htmlEscape(NAME_1),
layerId = ~NAME_1,
)
})
leafletOutput('map2')
# REGION SELECTION -----------------------------------------------------------------------
# Click event for the map to draw chart
click_poly2 <- eventReactive(input$map_shape_click, {
x <- input$map_shape_click
y <- x$id
return(y)
}, ignoreNULL = TRUE)
observe({
req(click_poly2()) # do this if click_poly() is not null
# Add the clicked poly and remove when a new one is clicked
map <- leafletProxy('map2') %>%
removeShape('NAME_1') %>%
addPolygons(data = adm1[adm1$NAME_1 == click_poly2(), ],
fill = FALSE,
weight = 4,
color = '#d01010',
opacity = 1,
layerId = 'NAME_1')
})
Column {data-width=350}
Plot 2
data2 <- reactive({
# Fetch data for the click poly
out <- df2[df2$NAME_1 == click_poly2(), ]
print("page 2") # print statement to show which click_poly is used
return(out)
})
output$plot2 <- renderHighchart({
req(data2()) # do this if click_poly() is not null
chart <- highchart() %>%
hc_chart(type = 'column') %>%
hc_legend(enabled = FALSE) %>%
hc_xAxis(categories = c('A'),
title = list(text = 'Title 2')) %>%
hc_yAxis(title = list(text = 'Value 2')) %>%
hc_plotOptions(series = list(dataLabels = list(enabled = TRUE))) %>%
hc_add_series(name = 'Series',
data = c(data2()$value_2)) %>%
hc_add_theme(hc_theme_smpl()) %>%
hc_colors(c('#d01010'))
})
highchartOutput('plot2')

Answer 1

In your click_poly2 <- eventReactive(input$map_shape_click, you have click_poly2 being the 2nd map, but you have the same map_shape_click, what if you made it map_shape_click2, hopefully flexdashboard will handle it differently as now they are 2 different maps

Answer 2

I figured out the answer myself following a similar question I found somewhere else. As I am quite new to shiny and based my code on examples I found, I did not realize that 'map_shape_click' applies 'shape_click' on 'map' where 'map' corresponds with the map in output$map. As I have two maps: map and map2, the eventReactive statement for page2 should be changed into
click_poly2 <- eventReactive(input$map2_shape_click, {
x <- input$map2_shape_click
y <- x$id
return(y)
}, ignoreNULL = TRUE)
Now responding to a shape_click on map2