R Shiny App：Rhandsontable 中的反应/计算列

Question

我正在使用 Rhansontable 包，我想创建一个表，如果我更改一列中的值，则另一列会自动计算。例如：

DF = data.frame(num = 1:10, price = 1:10,stringsAsFactors = FALSE)

在上面的数据框中，当我更改“num”列中的值时，另一列“Total”（num*price）应该自动计算

可以请帮助示例闪亮代码吗？

Answer 1

我想这就是你想要的

#rm(list = ls())
library(shiny)
library(rhandsontable)

## Create the dataset
DF = data.frame(num = 1:10, price = 1:10,Total = 1:10,stringsAsFactors = FALSE)
numberofrows <- nrow(DF)

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

  # Initiate your table
  previous <- reactive({DF})

  MyChanges <- reactive({
    if(is.null(input$hotable1)){return(previous())}
    else if(!identical(previous(),input$hotable1)){
      # hot.to.df function will convert your updated table into the dataframe
      mytable <- as.data.frame(hot_to_r(input$hotable1))
      # here the second column is a function of the first and it will be multipled by 100 given the values in the first column
      mytable <- mytable[1:numberofrows,]

      # Add some test cases
      mytable[,1][is.na(mytable[,1])] <- 1
      mytable[,2][is.na(mytable[,2])] <- 1
      mytable[,3] <- mytable[,1]*mytable[,2]
      mytable
    }
  })
  output$hotable1 <- renderRHandsontable({rhandsontable(MyChanges())})
})

ui <- basicPage(mainPanel(rHandsontableOutput("hotable1")))
shinyApp(ui, server)