leafletProxy not working in shinyDashboard

user_17493355 0
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leafletProxy doesn't seem to be functional within shinyDashboard. See working example below where choosing different letters should change the circle color. Any insight appreciated. Github issue created here: https://github.com/rstudio/shinydashboard/issues/377

library(shiny)
library(shinydashboard)
library(leaflet)
library(sf)

n = 100

df1 = data.frame(id = 1:n,
                 x = rnorm(n, 10, 3),
                 y = rnorm(n, 49, 1.8))

pts = st_as_sf(df1, coords = c("x", "y"), crs = 4326)

map <- leaflet() %>%
  addProviderTiles(provider = providers$CartoDB.DarkMatter) %>%
  addCircles(data = pts, group = "pts") %>%
  setView(lng = 10.5, lat = 49.5, zoom = 6)

ui <- dashboardPage(
  dashboardHeader(),
  
  dashboardSidebar(
    selectInput(inputId = 'click', 'Choose one:', c('A', 'B', 'C'))
  ),
  
  dashboardBody(
    fluidRow(
      div(
        id = "map",
        column(
          width = 12,
          leafletOutput('map', height = '800px')),
      )
    )
  )
)


server <- function(input, output) {
  output$map <- renderLeaflet({map})
  
  observeEvent(input$click, {
    col <- switch(input$click, 
                  'A' = 'green', 
                  'B' = 'yellow', 
                  'C' = 'white')
    
    m <- leafletProxy("map") %>%
      clearShapes() %>%
      addCircles(data = pts,
                 color = col)
    
    m
  })
  
}

shinyApp(ui, server)
shinydashboard r-leaflet shiny r
1 Answers

There are a two issues regarding your code:

  1. leafletProxy needs a session argument (added it to your server function)

  2. You placed your leaflet map in a div with the same id as your map. - Id's need to be unique.

library(shiny)
library(shinydashboard)
library(leaflet)
library(sf)

n = 100

df1 = data.frame(id = 1:n,
                 x = rnorm(n, 10, 3),
                 y = rnorm(n, 49, 1.8))

pts = st_as_sf(df1, coords = c("x", "y"), crs = 4326)

map <- leaflet() %>%
  addProviderTiles(provider = providers$CartoDB.DarkMatter) %>%
  addCircles(data = pts, group = "pts") %>%
  setView(lng = 10.5, lat = 49.5, zoom = 6)

ui <- dashboardPage(dashboardHeader(),
                    dashboardSidebar(selectInput(
                      inputId = 'color', 'Choose one:', list(A = 'green',
                                                             B = 'yellow',
                                                             C = 'white')
                    )),
                    dashboardBody(fluidRow(column(
                      width = 12,
                      leafletOutput('map', height = '800px')
                    ))))


server <- function(input, output, session) {
  output$map <- renderLeaflet({
    map
  })
  
  m <- leafletProxy("map", session)
  
  observeEvent(input$color, {
    m %>% clearShapes() %>%
      addCircles(data = pts,
                 color = input$color)
  }, ignoreInit = TRUE)
}

shinyApp(ui, server)
user_98413890
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