R Leaflet (CRAN) - 如何注册点击标记 [英] R Leaflet (CRAN) - how to register clicking off a marker

问题描述

在一个闪亮的应用程序中使用 RStudio Leaflet 包，我已经能够实现所有我一直在寻找的功能，除了在单击标记对象后取消选择它.

Using the RStudio Leaflet package in a shiny app I've been able to achieve all the functionality I've looked for except deselecting a marker object once it has been clicked on.

更具体地说，input$map_click_id 值在单击任何标记之前设置为 NULL.单击标记后，将使用该标记的数据(ID、lat、lng、nonce)进行更新.我想设置地图，以便当用户点击地图上不是标记的任何区域时，input$map_click_id 将重置为 NULL，直到单击另一个标记.

More specifically, the input$map_click_id value is set to NULL before any markers are clicked. Upon clicking a marker it is updated with the data (ID, lat, lng, nonce) for that marker. I would like to set the map up so that when a user clicks on any area of the map which is not a marker, input$map_click_id is reset to NULL until another marker is clicked.

我已经尝试了许多解决方案来解决这个问题，例如比较标记点击和地图点击的点击时间，但是标记点击变量一旦设置为非 NULL 值，就会在每次点击地图时更新，不管它是否在标记上，所以这不起作用.

I've tried a number of work around solutions for this such as comparing the click times for marker clicks and map clicks, but the marker click variable, once set to a non-NULL value, is updated everytime the map is clicked, regardless of whether it is on a marker or not, so this doesn't work.

这里的任何帮助将不胜感激！下面是一个非常小的可重现示例.在这种情况下，我希望在单击时将标记信息打印到控制台，并在单击地图的任何非标记区域时将 NULL 返回到控制台.

Any help here would be greatly appreciated! Below is a very minimal reproducable example. In this case I would like for the marker info to print to the console when it is clicked, and for NULL to be returned to the console when any non-marker area of the map is clicked.

library(leaflet)
library(shiny)

# set basic ui
ui <- fluidPage(
  leafletOutput("map")
)

server <- shinyServer(function(input, output) {

  # produce the basic leaflet map with single marker
  output$map <- renderLeaflet(
    leaflet() %>%
      addProviderTiles("CartoDB.Positron") %>%
      addCircleMarkers(lat = 54.406486, lng = -2.925284)

  )

  # observe the marker click info and print to console when it is changed.
  observeEvent(input$map_marker_click,
               print(input$map_marker_click)
               )

})


shinyApp(ui, server)

<小时>

这似乎与 问的问题相同在这里，但由于没有答案，我想我会再试一次.

---

This appears to be the same question as asked here but as there was no answer for this, I thought I'd try again.

推荐答案

您可以使用 reactiveValues 来存储点击的标记，并在用户点击地图背景时重置它:

You could use a reactiveValues to store the clicked marker and reset it whenever the user clicks on the map background:

server <- shinyServer(function(input, output) {
  data <- reactiveValues(clickedMarker=NULL)
  # produce the basic leaflet map with single marker
  output$map <- renderLeaflet(
    leaflet() %>%
      addProviderTiles("CartoDB.Positron") %>%
      addCircleMarkers(lat = 54.406486, lng = -2.925284)    
  )

  # observe the marker click info and print to console when it is changed.
  observeEvent(input$map_marker_click,{
               data$clickedMarker <- input$map_marker_click
               print(data$clickedMarker)}
  )
  observeEvent(input$map_click,{
               data$clickedMarker <- NULL
               print(data$clickedMarker)})
})

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