Note that this question has been posted at the R Shiny Google Group:
Following the Leaflet for R/ Shiny Integration documentation, I'm getting unwanted/ unexpected behavior with the leafletProxy function.
In the app below, I'd expect the circle markers to appear/ disappear as the input$choices changes.
The reactive df 'filteredData' seems to be working correctly.
Am I incorrectly using leafletProxy() or clearShapes()?
library(shiny)
library(dplyr)
library(leaflet)
my_df <- data.frame(lat = 34.72 + rnorm(1000, sd = .18),
lng = -92.5 + rnorm(1000, sd = .33),
category = c(rep("A", 300), rep("B", 300), rep("C", 400)))
ui <- bootstrapPage(
tags$style(type = "text/css", "html, body {width:100%;height:100%}"),
leafletOutput("map", height = '100%', width = '100%'),
absolutePanel(top = 10, right = 10,
checkboxGroupInput("choices", "Choices", choices = list("A","B","C"), selected = c("A","B","C")),
verbatimTextOutput("my_rows")
)
)
server <- function(input, output) {
filteredData <- reactive( my_df %>% filter(category %in% input$choices) )
output$map <- renderLeaflet({ leaflet() %>% addTiles() %>% setView(lat = 34.72, lng = -92.5, zoom = 9) })
observe({
leafletProxy("map", data = filteredData()) %>% clearShapes() %>% addCircleMarkers(radius = 6, weight = 1, fillColor = "red", fillOpacity = 0.3)
})
output$my_rows <- renderPrint({ filteredData() %>% nrow() })
}
shinyApp(ui = ui, server = server)
Your first issue is solved by using clearMarkers()
rather than clearShapes()
.
As to the other issue you pointed out, leaflet
struggles with empty (and NA) data. When you deselect all the values, your data.frame
obviously becomes empty. A simple check for this to stop leaflet
trying to plot it will solve this issue.
Here I'm using an if - else
do do the check.
library(shiny)
library(dplyr)
library(leaflet)
my_df <- data.frame(lat = 34.72 + rnorm(1000, sd = .18),
lng = -92.5 + rnorm(1000, sd = .33),
category = c(rep("A", 300), rep("B", 300), rep("C", 400)))
ui <- bootstrapPage(
tags$style(type = "text/css", "html, body {width:100%;height:100%}"),
leafletOutput("map", height = '100%', width = '100%'),
absolutePanel(top = 10, right = 10,
checkboxGroupInput("choices", "Choices"
, choices = list("A","B","C")
, selected = c("A","B","C")),
verbatimTextOutput("my_rows")
)
)
server <- function(input, output) {
filteredData <- reactive({
my_df %>% filter(category %in% input$choices)
})
output$map <- renderLeaflet({
leaflet() %>%
addTiles() %>%
setView(lat = 34.72, lng = -92.5, zoom = 9)
})
observe({
df <- filteredData()
## check for empty dataframe
if(nrow(df) == 0){
leafletProxy("map", data = df) %>%
clearMarkers()
}else{
leafletProxy("map", data = df) %>%
clearMarkers() %>%
addCircleMarkers(radius = 6, weight = 1
, fillColor = "red", fillOpacity = 0.3)
}
})
output$my_rows <- renderPrint({
filteredData() %>%
nrow()
})
}
shinyApp(ui = ui, server = server)