在tabItem()中动态创建box()

Question

我正在用shinydashboard构建一个shiny应用程序。它的目的是在每个tabItem() (即仪表板的每一页)中显示一组“卡片”(从技术上讲是box()元素)。应用程序由一个外部.csv文件(在这个reprex中是object dat)驱动，该文件(1)定义应用程序中的页面，(2)指定每个页面中的box()元素的数量。

我已经成功地使用dat中的类别创建了一组tabItem(即页面)。从这里，我想不出如何为每个tabItem动态添加正确数量的框。如果你检查dat，你会看到有两个类别(页面)：蓝色和绿色。蓝色类别需要我呈现两个框(框A和框B)，而绿色类别需要我呈现框C- E。因此，名为“蓝色”的页面应该呈现两个框，而名为“绿色”的页面应该呈现三个框。

有人能帮助我使用下面的代码，以便为正确的页面呈现正确的框吗？如果box_name和box_desc可以分别作为box()标题和内容出现，我将非常感谢！

library(shiny)
library(shinydashboard)

dat<-tibble::tibble(category = c("blue", "blue", "green", "green", "green"), 
                    box_name = c("Box A", "Box B", "Box C", "Box D", "Box E"),
                    box_desc = c("Foo", "Bar", "Bar", "Foo", "Foo"))

sidebar <- dashboardSidebar(
  sidebarMenu(
    menuItem("Blue", tabName = "blue", icon = icon("dashboard")),
    menuItem("Green", icon = icon("th"), tabName = "green")
  )
)

body <- dashboardBody(
  uiOutput("render_reports")
)
header<-dashboardHeader()

ui <- dashboardPage(header, sidebar, body)

server <- function(input, output) {
  
  output$render_reports <- renderUI({
    
    pages <- lapply(unique(dat$category), function(name){
      
      tabItem(tabName = name, fluidRow(box(
        title = name, paste0("Something here about ", name), width = 12, solidHeader = TRUE, status = "primary"
      )),

      fluidRow(
        
        box(title = "box_title here", "box_desc here")
        
      ))
    })
    
    items <- c(pages)
    do.call(tabItems, items)
    
  })
  
}


shinyApp(ui, server)

Answer 1

是否需要renderUI？

在没有renderUI的情况下，它工作得很好(而且速度更快

library(shiny)
library(shinydashboard)

dat <- tibble::tibble(
  category = c("blue", "blue", "green", "green", "green"),
  box_name = c("Box A", "Box B", "Box C", "Box D", "Box E"),
  box_desc = c("Foo", "Bar", "Bar", "Foo", "Foo")
)

sidebar <- dashboardSidebar(sidebarMenu(
  menuItem("Blue", tabName = "blue", icon = icon("dashboard")),
  menuItem("Green", tabName = "green", icon = icon("th"))
))

body <- dashboardBody({
  items <- lapply(unique(dat$category), function(name) {
    tabItem(tabName = name, fluidRow(
      lapply(which(dat$category %in% name), function(i) {
        box(
          dat$box_desc[i],
          title = dat$box_name[i],
          paste0("Something here about ", name),
          width = 12,
          solidHeader = TRUE,
          status = "primary"
        )
      }))
    )})
  do.call(tabItems, items)
})

header <- dashboardHeader()

ui <- dashboardPage(header, sidebar, body)

server <- function(input, output) {}

shinyApp(ui, server)

使用renderUI时，只有在切换选项卡之后才会呈现项目-因为在第一次呈现dashboardBody时，框并不存在：

library(shiny)
library(shinydashboard)

dat <- tibble::tibble(
  category = c("blue", "blue", "green", "green", "green"),
  box_name = c("Box A", "Box B", "Box C", "Box D", "Box E"),
  box_desc = c("Foo", "Bar", "Bar", "Foo", "Foo")
)

sidebar <- dashboardSidebar(sidebarMenu(
  menuItem("Blue", tabName = "blue", icon = icon("dashboard")),
  menuItem("Green", tabName = "green", icon = icon("th"))
))

body <- dashboardBody(uiOutput("renderReports"))
header <- dashboardHeader()

ui <- dashboardPage(header, sidebar, body)

server <- function(input, output) {
  output$renderReports <- renderUI({
    items <- lapply(unique(dat$category), function(name) {
      tabItem(tabName = name, fluidRow(
        lapply(which(dat$category %in% name), function(i) {
        box(
          dat$box_desc[i],
          title = dat$box_name[i],
          paste0("Something here about ", name),
          width = 12,
          solidHeader = TRUE,
          status = "primary"
        )
      }))
    )})
    do.call(tabItems, items)
  })
}

shinyApp(ui, server)