Question

server.R

reference <- input$a * input$b (More complex formula)

output$text <- rendertext({
if(reference > 20)
# Some text in red
else
# Some text in green
)}

我尝试使用conditionalPanel，但它不允许我更改面板反应性输出。

提前致谢

Answer 1

你可以做这样的事情

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      # Input to react to
      sliderInput('slider1','Render text format condition',-1000,1000,value=0,step=1)
    ),
    mainPanel(
      # Text input
      textInput('txtIn','Text input'),
      # Text output
      htmlOutput('txtOut')
    )
  )
)

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

  output$txtOut <- renderText({ 
    # Split into words
    words <- strsplit(input$txtIn,' ')[[1]]
    outTxt <- ' '

    # Parse input based on logic
    if(length(words) == 0) return('')

    # Loop trough words
    for (i in 1:length(words)){
      curr.word <- words[i]

      # If string can be converted to a number
      if(!is.na(as.numeric(curr.word))){
        curr.word.num <- as.numeric(curr.word) # Just in case

        # Determine formating
        if (curr.word.num >= input$slider1 ){
          font <- 'green'
        } else if (curr.word.num < input$slider1){
          font <- 'red'
        } else {
          font <- 'gray'
        }

        # Create html
        formatedFont <- sprintf('<font color="%s">%s</font>',font,curr.word) 

        # Append to text to show
        outTxt <- paste(outTxt, formatedFont,collapse=' ')

      } else{
        outTxt <- paste(outTxt, curr.word,collapse=' ')
      }
    }
    outTxt
  })

}

runApp(shinyApp(ui,server))

此处将文本输入解析为小于滑块输入红色且大于滑块输入绿色的颜色编号。普通文本未格式化。

诀窍是在输出文本中使用一些html格式

根据条件更改renderText的颜色

1 个答案: