从Shiny中渲染的传单地图中删除缩放控件

问题描述

在设置地图时，传单提供了一个选项，用于隐藏缩放控件

Leaflet provides an option, when setting up your map, to hide the zoom controls

leaflet(options = leafletOptions(zoomControl = FALSE)

但是，我想在创建地图后调用此选项，以便用户可以在没有缩放控件的情况下下载地图，而无需从头开始重新创建其他版本的地图.

However, I would like to call this option after having already created a map so that a user can download the map without the zoom controls and without me having to re-create a different version of the map from scratch.

这是我的应用程序的一个简单版本:

Here's a simple version of my app at the moment:

library(shiny)
library(tidyverse)
library(leaflet)
library(mapview)

ui <- fluidPage(
  fluidPage(
    leafletOutput(outputId = "map"),
    downloadButton(outputId = "save")
  )
)

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

  map <- reactive({
    leaflet() %>%
      addTiles()
  })

  output$map <- renderLeaflet({
    map()
  })

  output$save <- downloadHandler(
    filename = "map.jpeg",
    content = function(file){
      latRng <- range(input$map_bounds$north,
                      input$map_bounds$south)
      lngRng <- range(input$map_bounds$east,
                      input$map_bounds$west)
      map() %>%
        setView(lng = (lngRng[1] + lngRng[2])/2,
                lat = (latRng[1] + latRng[1])/2,
                zoom = input$map_zoom) %>%
        ### HERE ###
        mapshot(file = file)
    }
  )

}

shinyApp(ui, server)

我希望能够在注释### HERE ###的位置添加一行代码，以关闭缩放控件.在我的实际代码中，显示的地图确实非常复杂，具有很多选项，并且我不想为了两次删除所有代码而仅仅为了在初次调用leaflet()时删除缩放控件.

I'd like to be able to add a line of code where I've commented ### HERE ### that would turn off zoom controls. In my actual code the displayed map is really complex with lots of options and I wouldn't want to have all that code twice just for the sake of removing zoom controls in the initial call to leaflet().

谢谢

推荐答案

您可以这样做:

library(shiny)
library(tidyverse)
library(leaflet)
library(mapview)

ui <- fluidPage(
  fluidPage(
    leafletOutput(outputId = "map"),
    downloadButton(outputId = "save")
  )
)

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

  map <- reactive({
    leaflet() %>%
      addTiles()
  })

  output$map <- renderLeaflet({
    map()
  })

  output$save <- downloadHandler(
    filename = "map.jpeg",
    content = function(file){
      latRng <- range(input$map_bounds$north,
                      input$map_bounds$south)
      lngRng <- range(input$map_bounds$east,
                      input$map_bounds$west)
      m = map() %>%
        setView(lng = (lngRng[1] + lngRng[2])/2,
                lat = (latRng[1] + latRng[1])/2,
                zoom = input$map_zoom)
      m$x$options = append(m$x$options, list("zoomControl" = FALSE))
      mapshot(m, file = file)
    }
  )

}

shinyApp(ui, server)

，它将在创建地图后更新传单选项.我会将其合并到mapshot函数中，以有选择地删除zoomControl.

which is updating the leaflet options after map creation. I will incorporate this in the mapshot function to optionally remove the zoomControl.

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