Shiny 模块的附加输入仅更新一次

Additional inputs for Shiny module only get updated once

我试着将其归结为一个最小的示例,但我认为我必须提供或多或少的完整代码来说明问题。

基本上我想要一个闪亮的应用程序通过 processx 包充当 start/stop(多个)系统进程(主要是 BASH 脚本,用于科学工作流程)的用户友好 GUI。所以我制作了一个闪亮的模块,可以 start/stop 并显示进程日志(只是从 stderr+stdout 输出)。 script/command 运行 是在调用模块时决定的,而不是在模块本身。然后重要的是,可以根据脚本 运行 将其他选项传递给不同的进程,例如选择 input/output 文件夹、数据库文件、设置等

问题是每次单击 actionButton 时不会更新任何其他输入的值,因此再次单击开始按钮(触发 eventReactive)只会启动在没有新 options/setting.

的情况下再次处理

我已在此处附上完整代码并在我的 shinyapps.io 帐户上发布了示例应用程序,可在此处获取:https://kasperskytte.shinyapps.io/processxmodule/

library(shiny)

#shiny module to start asynchronous processes using processx package

#shiny must be version 1.4.0.9003 or later to use shiny modules, install from github
installGitHub <- function(...) {
  if(!require("remotes")) {
    install.packages("remotes")
  }
  remotes::install_github(...)
}

if(any(grepl("^shiny$", installed.packages()[,1]))) {
  if(packageVersion("shiny") < "1.4.0.9003") {
    installGitHub("rstudio/shiny")
  }
} else 
  installGitHub("rstudio/shiny")

require("shiny")
require("processx")

processxUI <- function(id) {
  shiny::tagList(
    uiOutput(NS(id, "startStopBtn")),
    p(),
    uiOutput(NS(id, "processStatus")),
    h4("Process log"),
    verbatimTextOutput(NS(id, "processLog")),
    downloadButton(NS(id, "downloadLogfile"), label = "Export log file")
  )
}

processxServer <- function(id, ...) {
  moduleServer(id, function(input, output, session) {
    #reactive to store processx R6 class object
    process <- reactiveVal()
    
    #reactive to store logfile created on start
    logfile <- reactiveVal(tempfile())
    
    #start/stop button
    output$startStopBtn <- renderUI({
      if(isFALSE(processAlive())) {
        actionButton(
          inputId = NS(id, "startStopProcess"),
          label = "Start process"
        )
      } else if(isTRUE(processAlive())) {
        actionButton(
          inputId = NS(id, "startStopProcess"),
          label = "Kill process"
        )
      }
    })
    
    #start a new process and logfile when actionbutton is pressed
    observeEvent(input$startStopProcess, {
      #start process if not already running, otherwise kill
      startProcess <- function(...) {
        #generate new log file for each new process
        logfile(tempfile())
        #start process piping stderr+stdout to logfile
        process(
          processx::process$new(
            ...,
            stderr = "2>&1",
            stdout = logfile(),
            supervise = TRUE
          )
        )
      }
      if(is.null(process()$is_alive))
        startProcess(...)
      else if(!is.null(process()$is_alive))
        if(isTRUE(process()$is_alive()))
          process()$kill_tree()
      else if(isFALSE(process()$is_alive()))
        startProcess(...)
    })
    
    #read process status every 500 ms (alive or not)
    #(only for updating status message below, otherwise use 
    # process()$is_alive() to avoid refresh interval delay)
    processAlive <- reactivePoll(
      intervalMillis = 500,
      session = session,
      checkFunc = function() {
        if(!is.null(process()$is_alive))
          process()$is_alive()
        else
          FALSE
      },
      valueFunc = function() {
        if(!is.null(process()$is_alive))
          process()$is_alive()
        else
          FALSE
      }
    )
    
    #print status message of process and exit status if finished
    output$processStatus <- renderUI({
      if(isTRUE(processAlive())) {
        p("Process is running...")
      } else if(isFALSE(processAlive()) && !is.null(process()$get_exit_status)) {
        if(process()$get_exit_status() == 0)
          p("Process has finished succesfully")
        else if(process()$get_exit_status() == -9)
          p("Process was killed")
        else if(!process()$get_exit_status() %in% c(0, -9))
          p(paste0("Process has errored (exit status: ", process()$get_exit_status(), ")"))
      }
    })
    
    #read logfile every 500 ms
    readLogfile <- reactivePoll(
      intervalMillis = 500,
      session = session,
      checkFunc = function() {
        if(file.exists(logfile()))
          file.info(logfile())[["mtime"]][1]
        else
          return('No process has run yet')
      },
      valueFunc = function() {
        if(file.exists(logfile()))
          readLines(logfile())
        else
          return('No process has run yet')
      }
    )
    
    #print process logfile
    output$processLog <- renderText({
      readLogfile()
    },
    sep = "\n")
    
    #export process logfile
    output$downloadLogfile <- downloadHandler(
      filename = function() {
        #append module id and date to logfile filename
        paste0("logfile_", id, "_", format(Sys.time(), format = "%y%m%d_%H%M%S"), ".txt")
      },
      content = function(file) {
        file.copy(from = logfile(), to = file)
      },
      contentType = "text/plain"
    )
  })
}

ui <- navbarPage(
  title = "test",
  tabPanel(
    title = "Test",
    column(
      width = 4,
      wellPanel(
        sliderInput(
          NS("process1", "delay"),
          "Sleep delay",
          min = 1,
          max = 5, 
          step = 1,
          value = 2)
      )
    ),
    column(
      width = 8,
      fluidRow(
        processxUI("process1")
      )
    )
  )
)

server <- function(input, output, session) {
  processxServer(
    "process1",
    command = "echo",
    args = as.character(reactive({input[[NS("process1", "delay")]]})())
  )
}

shinyApp(ui = ui, server = server)

错误是您没有将反应传递给您的模块。在行

processxServer(
    "process1",
    command = "echo",
    args = as.character(reactive({input[[NS("process1", "delay")]]})())
  )

您在将 reactive 传递给模块之前对其进行评估,因此模块仅在启动时获得默认值。我对其进行了更改,以便将未计算的 reactive 传递给模块,并且仅在您创建 startProcess 函数时对其进行计算。但是,这会使 ... 的灵​​活性降低,因为现在 startProcess 假设已传递参数 args

library(shiny)
library("processx")

#shiny module to start asynchronous processes using processx package

processxUI <- function(id) {
  shiny::tagList(
    uiOutput(NS(id, "startStopBtn")),
    p(),
    uiOutput(NS(id, "processStatus")),
    h4("Process log"),
    verbatimTextOutput(NS(id, "processLog")),
    downloadButton(NS(id, "downloadLogfile"), label = "Export log file")
  )
}

processxServer <- function(id, ...) {
  moduleServer(id, function(input, output, session) {
    #reactive to store processx R6 class object
    process <- reactiveVal()
    
    #reactive to store logfile created on start
    logfile <- reactiveVal(tempfile())
    
    #start/stop button
    output$startStopBtn <- renderUI({
      if(isFALSE(processAlive())) {
        actionButton(
          inputId = NS(id, "startStopProcess"),
          label = "Start process"
        )
      } else if(isTRUE(processAlive())) {
        actionButton(
          inputId = NS(id, "startStopProcess"),
          label = "Kill process"
        )
      }
    })
    
    #start a new process and logfile when actionbutton is pressed
    observeEvent(input$startStopProcess, {
      #start process if not already running, otherwise kill
      startProcess <- function(...) {
        #generate new log file for each new process
        logfile(tempfile())
        #start process piping stderr+stdout to logfile
        
        # make argument list
        dots <- list(...)
        dots$args <- as.character(dots$args())
        arg_list <- c(dots, stderr = "2>&1", stdout = logfile(), supervise = TRUE)
        
        process(
          do.call(processx::process$new, arg_list)
        )
      }
      if(is.null(process()$is_alive))
        startProcess(...)
      else if(!is.null(process()$is_alive))
        if(isTRUE(process()$is_alive()))
          process()$kill_tree()
      else if(isFALSE(process()$is_alive()))
        startProcess(...)
    })
    
    #read process status every 500 ms (alive or not)
    #(only for updating status message below, otherwise use 
    # process()$is_alive() to avoid refresh interval delay)
    processAlive <- reactivePoll(
      intervalMillis = 500,
      session = session,
      checkFunc = function() {
        if(!is.null(process()$is_alive))
          process()$is_alive()
        else
          FALSE
      },
      valueFunc = function() {
        if(!is.null(process()$is_alive))
          process()$is_alive()
        else
          FALSE
      }
    )
    
    #print status message of process and exit status if finished
    output$processStatus <- renderUI({
      if(isTRUE(processAlive())) {
        p("Process is running...")
      } else if(isFALSE(processAlive()) && !is.null(process()$get_exit_status)) {
        if(process()$get_exit_status() == 0)
          p("Process has finished succesfully")
        else if(process()$get_exit_status() == -9)
          p("Process was killed")
        else if(!process()$get_exit_status() %in% c(0, -9))
          p(paste0("Process has errored (exit status: ", process()$get_exit_status(), ")"))
      }
    })
    
    #read logfile every 500 ms
    readLogfile <- reactivePoll(
      intervalMillis = 500,
      session = session,
      checkFunc = function() {
        if(file.exists(logfile()))
          file.info(logfile())[["mtime"]][1]
        else
          return('No process has run yet')
      },
      valueFunc = function() {
        if(file.exists(logfile()))
          readLines(logfile())
        else
          return('No process has run yet')
      }
    )
    
    #print process logfile
    output$processLog <- renderText({
      readLogfile()
    },
    sep = "\n")
    
    #export process logfile
    output$downloadLogfile <- downloadHandler(
      filename = function() {
        #append module id and date to logfile filename
        paste0("logfile_", id, "_", format(Sys.time(), format = "%y%m%d_%H%M%S"), ".txt")
      },
      content = function(file) {
        file.copy(from = logfile(), to = file)
      },
      contentType = "text/plain"
    )
  })
}

ui <- navbarPage(
  title = "test",
  tabPanel(
    title = "Test",
    column(
      width = 4,
      wellPanel(
        sliderInput(
          NS("process1", "delay"),
          "Sleep delay",
          min = 1,
          max = 5, 
          step = 1,
          value = 2)
      )
    ),
    column(
      width = 8,
      fluidRow(
        processxUI("process1")
      )
    )
  )
)

server <- function(input, output, session) {
  processxServer(
    "process1",
    command = "echo",
    args = reactive({input[[NS("process1", "delay")]]})
  )
}

shinyApp(ui = ui, server = server)

此外,您对 delay 滑块的定义有点超出闪亮模块的概念。 NS 被认为是在模块 ui 中调用的,因此明确区分了哪些元素属于哪个名称空间的定义(但它显然也适用于您的方法)。