在 R 中使用 renderText() 输出多行文本

发布于04月27日

我想用一个renderText()命令输出多行文本.然而，这似乎是不可能的.例如，从shiny tutorial开始，我们在server.R中截断了代码:

shinyServer(
  function(input, output) {
    output$text1 <- renderText({paste("You have selected", input$var)
    output$text2 <- renderText({paste("You have chosen a range that goes from",
      input$range[1], "to", input$range[2])})
  }
)

代码为ui.R:

shinyUI(pageWithSidebar(

  mainPanel(textOutput("text1"),
            textOutput("text2"))
))

它基本上打印了两行:

You have selected example
You have chosen a range that goes from example range.

是否可以将第output$text1行和第output$text2行合并为一个代码块？到目前为止，我的努力都失败了.

output$text = renderText({paste("You have selected ", input$var, "\n", "You have chosen a range that goes from", input$range[1], "to", input$range[2])})

有人有什么 idea 吗？

推荐答案

你可以用renderUI和htmlOutput代替renderText和textOutput.

require(shiny)
runApp(list(ui = pageWithSidebar(
  headerPanel("censusVis"),
  sidebarPanel(
    helpText("Create demographic maps with 
      information from the 2010 US Census."),
    selectInput("var", 
                label = "Choose a variable to display",
                choices = c("Percent White", "Percent Black",
                            "Percent Hispanic", "Percent Asian"),
                selected = "Percent White"),
    sliderInput("range", 
                label = "Range of interest:",
                min = 0, max = 100, value = c(0, 100))
  ),
  mainPanel(textOutput("text1"),
            textOutput("text2"),
            htmlOutput("text")
  )
),
server = function(input, output) {
  output$text1 <- renderText({paste("You have selected", input$var)})
  output$text2 <- renderText({paste("You have chosen a range that goes from",
                                    input$range[1], "to", input$range[2])})
  output$text <- renderUI({
    str1 <- paste("You have selected", input$var)
    str2 <- paste("You have chosen a range that goes from",
                  input$range[1], "to", input$range[2])
    HTML(paste(str1, str2, sep = '<br/>'))

  })
}
)
)

注意你需要用<br/>作为换行符.此外，您希望显示的文本需要进行HTML转义，因此请使用HTML函数.