r - 使用 purrr::pwalk 从 tibble 创建多个 Shiny 的 observeEvents

Question

我想做什么
我想遍历一个tibble并创建多个observeEvents。我在下面有一个可重现的例子。注释掉的代码有效，但我想用 pwalk 以编程方式创建observeEvents。
基本上我试图完成与这篇文章类似的事情:using purrr::walk to instate multiple event observers .
(虽然目标不同。我的目标是在更改一个 selectInput 时跨选项卡更新 selectInputs。)
代表

library(shiny)
library(purrr)
library(tibble)

choices1 <- c('A', 'B', 'C', 'D')
choices2 <- c('E', 'F', 'G', 'H')

dat_inputs <- tribble(
  ~ observe_input, ~ input_id,
  'tab11',         'tab21',
  'tab11',         'tab31',
  'tab21',         'tab11',
  'tab21',         'tab31',
  'tab31',         'tab11',
  'tab31',         'tab21'
  
)

ui <- navbarPage(
  title = 'Test Navbar Page',
  tabPanel(
    title = 'Tab 1',
    selectInput('tab11', 'Tab 11', choices = choices1
    ),
    selectInput('tab12', 'Tab 12', choices = choices2
    )
    ),
  tabPanel(
    title = 'Tab 2',
    selectInput('tab21', 'Tab 22', choices = choices1
    ),
    selectInput('tab12', 'Tab 12', choices = choices2
    )
    ),
  tabPanel(
    title = 'Tab 3',
    selectInput('tab31', 'Tab 31', choices = choices1
    ),
    selectInput('tab32', 'Tab 32', choices = choices2
    )
    )
)

server <- function(input, output, session) {
  
  # observeEvent(input$tab11, {
  #   updateSelectInput(inputId = 'tab21', selected = input$tab11)
  #   updateSelectInput(inputId = 'tab31', selected = input$tab11)
  # })
  # 
  # observeEvent(input$tab21, {
  #   updateSelectInput(inputId = 'tab11', selected = input$tab21)
  #   updateSelectInput(inputId = 'tab31', selected = input$tab21)
  # })
  # 
  # observeEvent(input$tab31, {
  #   updateSelectInput(inputId = 'tab11', selected = input$tab31)
  #   updateSelectInput(inputId = 'tab21', selected = input$tab31)
  # })
  
# edit - commenting out the old code so that the solution takes its place
  
  # this code does not work
  # if you delete handler.quoted = TRUE the shiny app runs but the
  # observeEvents don't work
  
  # pwalk(
#   dat_inputs,
#   ~ observeEvent(
#     input[[.x]],
#     updateSelectInput(inputId = input[[.y]], selected = input[[.x]]),
#     handler.quoted = TRUE
#   )
# )

################################
# solution from accepted answer:
################################
pwalk(
    dat_inputs,
    ~ observeEvent(
        input[[.x]],
        updateSelectInput(inputId = .y, selected = input[[.x]],
                          session = session)
        )
  ) 
  
}

shinyApp(ui, server)

Answer 1

嗯，三件事，你正在使用 input=input[[.y]]而不仅仅是 input=.y ;当你使用这样的表达式时，它实际上没有被引用；你需要传递session= .尝试

pwalk(
    dat_inputs,
    ~ observeEvent(
      input[[.x]],
      updateSelectInput(inputId = .y, selected = input[[.x]], session=session)
    )
  )