創建 shiny 模塊，該模塊在 Z531704A02607A1646EFCF4C1FAE1EEC 中創建 leaflet map

Question

我在下面有一個簡單的 shiny 應用程序，我在其中創建了一個 leaflet map。 我想創建一個 shiny 模塊，盡管它會專門創建 leaflet map。

    ## app.R ##
library(shiny)
library(shinydashboard)
library(shinyWidgets)
library(leaflet)
library(dplyr)

# Some data
data<-structure(list(scientificName = c("Turdus merula Linnaeus, 1758", 
                                        "Passer domesticus (Linnaeus, 1758)", "Cantharellus cinereus (Pers.) Fr.", 
                                        "Flammulina fennae Bas", "Mycena crocata (Schrad.) P.Kumm.", 
                                        "Lepista luscina (Fr.) Singer", "Mycena permixta (Britzelm.) Sacc.", 
                                        "Rhodophyllus byssisedus (Pers.) Quel.", "Rhodophyllus porphyrophaeus (Fr.) J.E.Lange", 
                                        "Panaeolus rickenii Hora"), decimalLatitude = c(52.204429, 51.387818, 
                                                                                        52.176667, 50.066111, 49.179167, 49.419444, 52.3, 52.3, 49.419444, 
                                                                                        49.179167), decimalLongitude = c(21.189275, 19.62673, 19.088056, 
                                                                                                                         19.502778, 22.434722, 20.380556, 20.566667, 20.566667, 20.380556, 
                                                                                                                         22.434722)), row.names = c(1L, 2L, 32L, 35L, 37L, 38L, 39L, 40L, 
                                                                                                                                                    41L, 42L), class = c("spec_tbl_df", "tbl_df", "tbl", "data.frame"
                                                                                                                                                    ))
# Define the side panel UI and server
sideUI <- function(id) {
  ns <- NS(id)
  pickerInput(
    inputId = ns("sci"),
    label = "Scientific name", 
    choices = unique(data$scientificName),
    selected = unique(data$scientificName)[1] 
    
  )
  actionButton("action","Submit")
  
}

sideServer <- function(id) {
  moduleServer(
    id,
    function(input, output, session) {
      
      # define a reactive and return it
      react<-eventReactive(input$action,{
        
        omited <-subset(data, data$scientificName %in% isolate(input$sci))
      })
      return(react)
      
    })
}
# In this case this server not needed but using uiOuput/renderUI in real case
# sideServer <- function(id) { moduleServer(id,function(input, output, session) { })}

# Define the UI and server functions for the map
mapUI <- function(id) {
  ns <- NS(id)
  leafletOutput(ns("map"))
}

mapServer <- function(id, city) {
  moduleServer(
    id,
    function(input, output, session) {
      output$map<-renderLeaflet({
        
        leaflet(data = react()) %>% addTiles() %>%
          addMarkers(~decimalLatitude, ~decimalLongitude, popup = ~as.character(scientificName), label = ~as.character(scientificName))
      })
    })
}

# Build ui & server and then run
ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(sideUI("side")),
  dashboardBody(mapUI("mapUK"))
)
server <- function(input, output, session) {
  
  # use the reactive in another module
  city_input <- sideServer("side")
  mapServer("mapUK", city_input)
  
}
shinyApp(ui, server)

Answer 1

你犯了一些錯誤。

下面是沒有這些錯誤的代碼：

library(shiny)
library(shinydashboard)
library(shinyWidgets)
library(leaflet)
library(dplyr)

# Some data
data<-structure(list(scientificName = c("Turdus merula Linnaeus, 1758", 
                                        "Passer domesticus (Linnaeus, 1758)", "Cantharellus cinereus (Pers.) Fr.", 
                                        "Flammulina fennae Bas", "Mycena crocata (Schrad.) P.Kumm.", 
                                        "Lepista luscina (Fr.) Singer", "Mycena permixta (Britzelm.) Sacc.", 
                                        "Rhodophyllus byssisedus (Pers.) Quel.", "Rhodophyllus porphyrophaeus (Fr.) J.E.Lange", 
                                        "Panaeolus rickenii Hora"), decimalLatitude = c(52.204429, 51.387818, 
                                                                                        52.176667, 50.066111, 49.179167, 49.419444, 52.3, 52.3, 49.419444, 
                                                                                        49.179167), decimalLongitude = c(21.189275, 19.62673, 19.088056, 
                                                                                                                         19.502778, 22.434722, 20.380556, 20.566667, 20.566667, 20.380556, 
                                                                                                                         22.434722)), row.names = c(1L, 2L, 32L, 35L, 37L, 38L, 39L, 40L, 
                                                                                                                                                    41L, 42L), class = c("spec_tbl_df", "tbl_df", "tbl", "data.frame"
                                                                                                                                                    ))
# Define the side panel UI and server
sideUI <- function(id) {
  ns <- NS(id)
  tagList(
    pickerInput(
      inputId = ns("sci"),
      label = "Scientific name", 
      choices = unique(data$scientificName),
      selected = unique(data$scientificName)[1] 
      
    ),
    actionButton(ns("action"),"Submit")
  )
  
}

sideServer <- function(id) {
  moduleServer(
    id,
    function(input, output, session) {
      
      # define a reactive and return it
      react<-eventReactive(input$action,{
        
        omited <-subset(data, data$scientificName %in% isolate(input$sci))
      })
      
      return(react)
      
    })
}
# In this case this server not needed but using uiOuput/renderUI in real case
# sideServer <- function(id) { moduleServer(id,function(input, output, session) { })}

# Define the UI and server functions for the map
mapUI <- function(id) {
  ns <- NS(id)
  tagList(
    leafletOutput(ns("map"))
  )
}

mapServer <- function(id, city) {
  moduleServer(
    id,
    function(input, output, session) {
      output$map<-renderLeaflet({
        
        leaflet(data = city()) %>% addTiles() %>%
          addMarkers(~decimalLatitude, ~decimalLongitude, popup = ~as.character(scientificName), label = ~as.character(scientificName))
      })
    })
}

# Build ui & server and then run
ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(sideUI("side")),
  dashboardBody(mapUI("mapUK"))
)
server <- function(input, output, session) {
  
  # use the reactive in another module
  city_input <- sideServer("side")
  mapServer("mapUK", city_input)
  
}
shinyApp(ui, server)

1. 始終在模塊的 UI 中使用tagList() 。 有時它可以在沒有它的情況下工作，但通常不會。
2. 在這一行： actionButton(ns("action"),"Submit")你錯過了ns() 。
3. 在這一行中： leaflet(data = city()) %>% addTiles() %>%您使用了react()而不是city() 。 這是錯誤的，因為你的 function 中沒有參數react ，但是city ，所以你必須參考city 。 This is the same as in normal function, ie you need to refer to the parameter in function to use arguments passed to this function.