在 R 闪亮数据表中添加和删除行时出现问题

Question

我正在尝试在 r shiny 中添加一个可编辑的数据表。我有两个组件。首先是允许用户添加新行并删除选定行。其次，当用户更改单元格中的任何值时，它应该更新相应的单元格。我首先面临的问题是无法删除选定的行。我可以添加这些但不能删除。下面是我正在使用的代码。另外我正在尝试重置为默认表，但它不会重置为默认表。我怎样才能解决这个问题。谢谢。

### Libraries
library(shiny)
library(dplyr)
library(DT)

### Data
input_data <- data.frame(aa = c("Brand1", "Brand2","Brand3"),
                         bb = c(2000, 3000, 4000),
                         cc = c (.5, .5, .5),
                         dd = c(2000, 3000, 4000),
                         ee = c (.5, .5, .5),
                         ff = c (.5, .5, .5),
                         gg = c (.5, .5, .5),
                         stringsAsFactors = FALSE)

### Shiny App
shinyApp(
  ui = basicPage(
    mainPanel(

      actionButton("reset", "Reset"),
      actionButton("add_btn", "Add"),
      actionButton("delete_btn", "Delete"),
      tags$hr(),
      DT::dataTableOutput("mod_table")    )
  ),
  server = function(input, output) {

    #demodata<-input_data

    this_table <- reactiveVal(input_data)

    observeEvent(input$add_btn, {
      t = rbind(data.frame(aa = "default",
                           bb = 1000000,cc = 2.0,dd = 20000, ee = 40,ff = 00 , gg = 00), this_table())
      this_table(t)
    })

    observeEvent(input$delete_btn, {
      t = this_table()
      print(nrow(t))
      if (!is.null(input$shiny_table_rows_selected)) {
        t <- t[-as.numeric(input$shiny_table_rows_selected),]
      }
      this_table(t)
    })
observeEvent(input$reset, {
       this_table <- input_data # your default data
     })

    output$mod_table <- DT::renderDataTable({
      datatable(this_table(), selection = 'single',editable = TRUE, options = list(dom = 't'))

    })
    }
)

Answer 1

删除行：

您使用input$tableId_rows_selected 获得选定的行。您的tableId 是mod_table。

因此，如果您将 input$shiny_table_rows_selected 更改为 input$mod_table_rows_selected，它将起作用。

重置表格：

如果您从分配给this_table 切换到使用this_table() 作为“设置函数”，它将起作用。我认为这只是一个小错字，因为您已经正确地将这种语法用于“删除部分”：

observeEvent(input$reset, {
  this_table(input_data)
})

可重现的代码：

library(shiny)
library(dplyr)
library(DT)

### Data
input_data <- data.frame(aa = c("Brand1", "Brand2","Brand3"),
                         bb = c(2000, 3000, 4000),
                         cc = c (.5, .5, .5),
                         dd = c(2000, 3000, 4000),
                         ee = c (.5, .5, .5),
                         ff = c (.5, .5, .5),
                         gg = c (.5, .5, .5),
                         stringsAsFactors = FALSE)

### Shiny App
shinyApp(
  ui = basicPage(
    mainPanel(

      actionButton("reset", "Reset"),
      actionButton("add_btn", "Add"),
      actionButton("delete_btn", "Delete"),
      tags$hr(),
      DT::dataTableOutput("mod_table")    )
  ),
  server = function(input, output) {

    #demodata<-input_data

    this_table <- reactiveVal(input_data)

    observeEvent(input$add_btn, {
      t = rbind(data.frame(aa = "default", bb = 1000000,cc = 2.0, dd = 20000, 
                           ee = 40,ff = 00 , gg = 00), this_table())
      this_table(t)
    })

    observeEvent(input$delete_btn, {
      t = this_table()
      print(input$mod_table_rows_selected)
      if (!is.null(input$mod_table_rows_selected)) {
        t <- t[-input$mod_table_rows_selected,]
      }
      this_table(t)
    })

    observeEvent(input$reset, {
      this_table(input_data)
    })

    output$mod_table <- DT::renderDataTable({
      datatable(this_table(), selection = 'single',editable = TRUE, 
                options = list(dom = 't'))
    })
  }
)

Answer 2

JavaScript 解决方案：

library(shiny)
library(DT)

### Data
input_data <- data.frame(aa = c("Brand1", "Brand2","Brand3"),
                         bb = c(2000, 3000, 4000),
                         cc = c (.5, .5, .5),
                         dd = c(2000, 3000, 4000),
                         ee = c (.5, .5, .5),
                         ff = c (.5, .5, .5),
                         gg = c (.5, .5, .5),
                         stringsAsFactors = FALSE)

### Callback
callback <- c(
  '$("#add_btn").on("click", function(){',
  '  var newrow = ["default", 1000000, 2, 20000, 40, 0, 0];',
  '  table.row.add(newrow).draw();',
  '});',
  '$("#delete_btn").on("click", function(){',
  '  var rows = table.rows(".selected");',
  '  rows.remove().draw();',
  '});'
)

### Shiny App
shinyApp(
  ui = basicPage(
    mainPanel(
      br(),
      actionButton("reset", "Reset"),
      actionButton("add_btn", "Add"),
      actionButton("delete_btn", "Delete"),
      tags$hr(),
      DTOutput("mod_table")
    )
  ),

  server = function(input, output) {

    output$mod_table <- renderDT({
      input$reset
      datatable(input_data, selection = 'single', editable = TRUE, 
                rownames = FALSE, 
                options = list(dom = 't'), callback = JS(callback))
    }, server = FALSE)

  }
)