Question

我有一个复杂的闪亮应用程序，在其中我使用'<-'在非反应数据上创建新列。

# Without reactive expression
ui <- fluidPage(tableOutput("contents"))
server1 <- function(input, output) {

  myData <- mtcars
  myData$New1 <- rep("NV1", nrow(myData))
  myData$New2 <- rep("NV2", nrow(myData))
  myData$New3 <- rep("NV3", nrow(myData))
  myData$New4 <- rep("NV4", nrow(myData))

  output$contents <- renderTable(myData)
}

shinyApp(ui, server1)

现在，我想将非反应性数据替换为反应性。如何以最小的变化做到这一点？我已经尝试过类似的东西：

# With reactive expression
ui <- fluidPage(tableOutput("contents"))

server2 <- function(input, output) {

  all <- reactiveValues()
  all$d <- mtcars

  all$d$New1 <- rep("NV1", nrow(all$d))
  all$d$New2 <- rep("NV2", nrow(all$d))
  all$d$New3 <- rep("NV3", nrow(all$d))
  all$d$New4 <- rep("NV4", nrow(all$d))

  output$contents <- renderTable(all$d)
}

shinyApp(ui, server2)

Answer 1

您可以执行以下操作：

ui <- fluidPage(tableOutput("contents"))

server2 <- function(input, output) {

  # you can assign variables in reactiveValues(), no need to make a new line
  all <- reactiveValues(d = mtcars) 

  observeEvent(all$d, { # update all$d, after it is created
  req(!is.null(all$d))

  all$d$New1 <- rep("NV1", nrow(all$d))
  all$d$New2 <- rep("NV2", nrow(all$d))
  all$d$New3 <- rep("NV3", nrow(all$d))
  all$d$New4 <- rep("NV4", nrow(all$d))
})
  output$contents <- renderTable(all$d)
}

用反应性数据替换非反应性数据

1 个答案: