在 R Shiny 中对变量进行两次索引

Question

我正在尝试对我的 Shiny 应用程序进行一些集成测试，但我不知道我做错了什么。我怀疑这与我在尝试访问可能性、颜色和 riskMessage 变量时使用了两次“$”有关。 我一直遇到这个错误：

Error in checkEqualsNumeric(output$coloredBox$likelihoodOfHarm, 0.75) : 
  Modes: NULL, numeric
Lengths: 0, 1
target is NULL, current is numeric

这是我的 Shiny 应用程序代码，我尝试在底部测试 Shiny 应用程序。非常感谢任何帮助！

displayColoredBox<- function(color, riskMessage){
  sidebarPanel(style=sprintf("background-color: %s; width: 300px; height: 300px;", color),
               h3(sprintf("%s", riskMessage)) )  }

app <- shinyApp(
  ui = fluidPage(
    
    div(
      id = "form",
      sliderInput("count1", "First Slider Input", value=0, min=0, max=5000),
      sliderInput("count2", "Second Slider Input", value=0, min=0, max=5000),
      uiOutput("coloredBox")
    )),
  
  server <- function(input, output, session) {
    
    output$coloredBox<-renderUI({
      req(input$count1)
      req(input$count2)
      
      count1 <- input$count1;
      count2 <- input$count2;
      
      likelihood <- (count1*count2)/5000000
      
      if (likelihood>1) {
        color="red"
        riskMessage="Extreme risk!"
        
      } else if (likelihood>.65){
        color="orange"
        riskMessage="Very high risk!"
      }
      else if (likelihood>.35){
        color="yellow"
        riskMessage="High risk!"
      }
      else if (likelihood>.10){
        color="blue"
        riskMessage="Moderate risk!"
      } else {
        color="green"
        riskMessage="Low risk!"
      }
      
      coloredBox=displayColoredBox(color, riskMessage)
      
    })
  }
)

testServer(app, {
  session$setInputs(count1 = 1500)
  session$setInputs(count2 = 2500)

  checkEqualsNumeric(output$coloredBox$likelihood, 0.75)
  checkEquals(output$coloredBox$riskMessage, "Very high risk!")
  checkEquals(output$coloredBox$color, "orange")

  
})

Answer 1

output Shiny Apps 中的对象不是您可以尝试访问的列表。相反，它们是 HTML 对象。闪亮的方式如下：将您的值存储为根据输入变化的反应式。检查反应物是否具有所需的值。

displayColoredBox<- function(color, riskMessage){
  sidebarPanel(style=sprintf("background-color: %s; width: 300px; height: 300px;", color),
               h3(sprintf("%s", riskMessage)) )  }

library(RUnit)
app <- shinyApp(
  ui = fluidPage(
    
    div(
      id = "form",
      sliderInput("count1", "First Slider Input", value=0, min=0, max=5000),
      sliderInput("count2", "Second Slider Input", value=0, min=0, max=5000),
      uiOutput("coloredBox")
    )),
  
  server <- function(input, output, session) {
    
    likelihood <- reactive((input$count1*input$count2)/5000000)
    boxValues <- reactiveValues(color="", riskMessage="")
    
    observe({
      req(input$count1)
      req(input$count2)
      if (likelihood()>1) {
        boxValues$color="red"
        boxValues$riskMessage="Extreme risk!"
        
      } else if (likelihood()>.65){
        boxValues$color="orange"
        boxValues$riskMessage="Very high risk!"
      }
      else if (likelihood()>.35){
        boxValues$color="yellow"
        boxValues$riskMessage="High risk!"
      }
      else if (likelihood()>.10){
        boxValues$color="blue"
        boxValues$riskMessage="Moderate risk!"
      } else {
        boxValues$color="green"
        boxValues$riskMessage="Low risk!"
      }
    })
    
    
    output$coloredBox<-renderUI({
      displayColoredBox(boxValues$color, boxValues$riskMessage)
    })
  }
)


testServer(app, {
  session$setInputs(count1 = 1500)
  session$setInputs(count2 = 2500)
  
  checkEquals(likelihood(), 0.75)
  checkEquals(boxValues$riskMessage, "Very high risk!")
  checkEquals(boxValues$color, "orange")
  
  
})