为Shiny中的Leaflet选择输入

Question

我正在尝试使用shiny构建一个带有leaflet的地图，但是我的代码不会根据选择的输入更改leaflet地图。有人知道如何让下面的代码react来做select输入吗？我试图用get函数来做这件事，但是不能成功。任何帮助都将不胜感激！

以下是我的数据：

> datamap
         Country.code EVENTONE EVENTTWO EVENTTHREE
1  Bosnia and Herzegovina       11        1          5
2             South Korea        1        4          4
3             Philippines        1        5          6
4               Indonesia        1        6          8
5                Thailand        1        0          9
6                Mongolia        1        0          3
7      Russian Federation        1        0          4
8                 Ukraine        1        0          8
9                Slovenia        1        0          5
10               Mongolia        1        0          0
11               Pakistan        1        0          0
12             Bangladesh        1        0          0

下面是我的代码：

library(shiny)
library(rworldmap) 
library(ggplot2)



shinyUI(fluidPage( 
  fluidRow(h1("Events in the World", align = "center")),
  fluidRow(
    column(2,

       selectInput("var", "Choose the Type Event:",
                   choices=c("Event One" = "EVENTONE", 
                             "Event Two" = "EVETNTWO", 
                             "Event Three" = "EVENTTHREE"))

),

column(10,

       tabsetPanel(
         tabPanel("Map View", leafletOutput("TheMap", width = "100%")
         )

       ) #end tabset panel
    )
  ) 
))

shinyServer(function(input, output) {

  datamap <- read.csv(".../Documents/R Directory/App-4/mapexcel4CSV.csv",             
                  stringsAsFactors=FALSE, header=TRUE)
  sPDF <- joinCountryData2Map(datamap, joinCode='NAME',       
                          nameJoinColumn='Country.code')
  sPDF <- sPDF[sPDF$ADMIN!='Antarctica',]

  output$TheMap <- renderLeaflet({
  mapselect <- get(input$var)
  pal <- colorBin("YlOrRd", domain = mapselect) 
  labels <- sprintf(
    "<strong>%s</strong><br/>Number of events: %g</sup>",
    sPDF$NAME, sPDF$mapselect
  ) %>% lapply(htmltools::HTML)

  TheMap<- leaflet(data = sPDF) %>% addTiles() %>% addPolygons(stroke = FALSE) %>% addPolygons(
  fillColor = ~pal(mapselect),
  weight = 2,
  opacity = 1,
  color = "white",
  dashArray = "3",
  fillOpacity = 0.7,
  highlight = highlightOptions(
    weight = 5,
    color = "#666",
    dashArray = "",
    fillOpacity = 0.7,
    bringToFront = TRUE),
  label = labels,
  labelOptions = labelOptions(
    style = list("font-weight" = "normal", padding = "3px 8px"),
    textsize = "15px",
    direction = "auto"))
  }
  )  
})
shinyApp(ui = ui, server = server)

任何帮助都是非常感谢的！

Answer 1

我猜这就是你的目标：

library(shiny)
  library(rworldmap) 
  library(ggplot2)
  library(leaflet)



 ui <-  shinyUI(fluidPage( 
    fluidRow(h1("Events in the World", align = "center")),
    fluidRow(
      column(2,

             selectInput("var", "Choose the Type Event:",
                         choices=c("Event One" = "EVENTONE", 
                                   "Event Two" = "EVENTTWO", 
                                   "Event Three" = "EVENTTHREE"))

      ),

      column(10,

             tabsetPanel(
               tabPanel("Map View", leafletOutput("TheMap", width = "100%")
               )

             ) #end tabset panel
      )
    ) 
  ))

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

    datamap <- read.csv("E:/test.csv",             
                        stringsAsFactors=FALSE, header=TRUE)
    sPDF <- joinCountryData2Map(datamap, joinCode='NAME',       
                                nameJoinColumn='Country.code')
    sPDF <- sPDF[sPDF$ADMIN!='Antarctica',]
    legVal <-  c(min(datamap[,-1]), max(datamap[,-1]) )
    output$TheMap <- renderLeaflet({
      mapselect <- input$var
      pal <- colorBin("YlOrRd", domain = as.numeric(sPDF[[mapselect]]))
      labels <- sprintf(
        "<strong>%s</strong><br/>Number of events: %g</sup>",
        sPDF$NAME, sPDF[[mapselect]]
      ) %>% lapply(htmltools::HTML)

      TheMap<- leaflet(data = sPDF) %>% addTiles() %>% addPolygons(stroke = FALSE) %>% addPolygons(
        fillColor = ~pal(as.numeric(sPDF[[mapselect]])),
        weight = 2,
        opacity = 1,
        color = "white",
        dashArray = "3",
        fillOpacity = 0.7,
        highlight = highlightOptions(
          weight = 5,
          color = "#666",
          dashArray = "",
          fillOpacity = 0.7,
          bringToFront = TRUE),
        label = labels,
        labelOptions = labelOptions(
          style = list("font-weight" = "normal", padding = "3px 8px"),
          textsize = "15px",
          direction = "auto"))%>% addLegend("bottomleft", pal = pal, value = legVal)
    }
    )  
  })
  shinyApp(ui = ui, server = server)

希望它能帮上忙！