如何在单击 actionButton 时更新数据表？

Question

所以我在 Shiny 中有一个数据表，我只想在用户更改输入参数并单击按钮时更新它。以下是它的最小可重现示例：

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

ui <- fluidPage(
  fluidRow(
    column(3, numericInput("num1", "Limiter1", value = 0)),
    column(3, numericInput("num2", "Limiter2", value = 0))
  ),
  fluidRow(
    column(3,actionButton("button1", "Apply filters1")),
    column(3,actionButton("button2", "Apply filters2"))
  ),
  fluidRow(
    column(6,dataTableOutput("testtable1")),
    column(6,dataTableOutput("testtable2"))
  )
)

server <- function(input, output, session) {
  filteredData1 <- reactive({
    req(input$num1)
    iris %>%
      filter(Petal.Length >= input$num1)
  })

  observeEvent(input$button1, {
    updateNumericInput(session, "num2", value = input$num1)

    output$testtable1 <- renderDataTable(datatable(filteredData1()))
  })

  filteredData2 <- reactive({
    req(input$num2)
    iris %>%
      filter(Petal.Length >= input$num2)
  })

  observeEvent(input$button2, {
    output$testtable2 <- renderDataTable(datatable(filteredData2()))
  })
}

shinyApp(ui, server)

不幸的是，在这种情况下，数据表会在用户单击按钮时首先加载，但之后会在每次 input$num1 更改时自动更新，无论是否单击 button1。有没有办法只在点击button1 时才用新参数更新表格？

Answer 1

如果应用程序如此简单，您只需将actionButton 更改为submitButton

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

ui <- fluidPage(
  fluidRow(
    numericInput("num1", "Limiter", value = 0)
    ),
  fluidRow(
    submitButton("button1", "Apply filters")
    ),
  fluidRow(
    dataTableOutput("testtable")
    )
)

server <- function(input, output, session) {
  filteredData <- reactive({
    req(input$num1)
    iris %>%
      filter(Petal.Length >= input$num1)
  })

  output$testtable <- renderDataTable(datatable(filteredData()))
}

shinyApp(ui, server)

Answer 2

带有反应值：

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

ui <- fluidPage(
  fluidRow(
    numericInput("num1", "Limiter", value = 0)
  ),
  fluidRow(
    actionButton("button1", "Apply filters")
  ),
  fluidRow(
    dataTableOutput("testtable")
  )
)

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

  filteredData <- reactiveVal(iris)
  observeEvent(input$button1, {
    filteredData(iris %>% filter(Petal.Length >= input$num1))
  })

  output$testtable <- renderDataTable(datatable(filteredData()))
}

shinyApp(ui, server)