Question

ui.R：

library(shiny) 
shinyUI( fluidPage(fluidRow(
    column(input$PYR, 
     style = 'padding:25px', 
     textInput("N_PYR", NULL, width = '192px'), 
     textInput("RATE_PYR", NULL, width = '192px'), 
     width = 3), 
    column(input$CYR, 
      style = 'padding:25px', 
      textInput("N_CYR", NULL, width = '192px'), 
      textInput("RATE_CYR", NULL, width = '192px'), 
      width = 3) 

))) 

server.R：

library(shiny) 
shinyServer(function(input, output, session) { 
    # current year ("2015-16" for example) 
    input$CYR <- reactive({"2015-16"}) 

    input$PYR <- reactive({paste0(
    as.numeric(substr(input$CYR, start = 1, stop = 4)-1), 
    "-", 
    as.numeric(substr(input$CYR, start = 6, stop = 7)-1)) 
    }) 

    # terminate when window is closed 
    session$onSessionEnded(function() { stopApp() }) 

}) 

如果ui.R改爲

library(shiny) 
shinyUI( fluidPage(fluidRow(
    column("2014-15", 
     style = 'padding:25px', 
     textInput("N_PYR", NULL, width = '192px'), 
     textInput("RATE_PYR", NULL, width = '192px'), 
     width = 3), 
    column("2015-16", 
      style = 'padding:25px', 
      textInput("N_CYR", NULL, width = '192px'), 
      textInput("RATE_CYR", NULL, width = '192px'), 
      width = 3) 

))) 

這是所需產品：

目標：聲明一個字符串變量，其值將NOT從用戶端給出（這將在R代碼進行手動更改），以便每當CYR值被改變的UI被更新。這個變量是否在ui.R或server.R中聲明並不重要。

Answer 1

看起來像renderUI是你所需要的。另外請注意，您的substr是不正確的我固定它

#rm(list = ls()) 
library(shiny) 
ui <- fluidPage(uiOutput("ui1")) 

server <- function(input, output, session) { 
    # current year ("2015-16" for example) 
    CYR <- reactive({"2015-16"}) 
    PYR <- reactive({ 
    paste0(
     as.numeric(substr(CYR(), start = 1, stop = 4))-1, 
     "-", 
     as.numeric(substr(CYR(), start = 6, stop = 7))-1) 
    }) 

    output$ui1 <- renderUI({ 
    fluidRow(
    column(PYR(), 
      style = 'padding:25px', 
      textInput("N_PYR", NULL, width = '192px'), 
      textInput("RATE_PYR", NULL, width = '192px'), 
      width = 3), 
    column(CYR(), 
      style = 'padding:25px', 
      textInput("N_CYR", NULL, width = '192px'), 
      textInput("RATE_CYR", NULL, width = '192px'), 
      width = 3)) 
    }) 
    # terminate when window is closed 
    session$onSessionEnded(function() { stopApp() }) 
} 

shinyApp(ui, server)