使用Shiny URL书签还原输入值并重新运行计算

Question

因此，我有一个闪亮的应用程序用例，用户可以在其中输入一些值，当单击运行时，它将运行模型并在表中显示值。现在，当我单击书签时，它将捕获输入值。当我单击还原书签时，它确实会填充输入值。我想做的是，在还原输入值之后，它还应该再次运行模型并填充表中的值。简而言之，还原书签应填充值，然后单击运行按钮以运行模型。如何实现？

下面是书签的代码：

library(shiny)
library(RSQLite)
library(data.table)

ui <- function(request) {
  fluidPage(
    DT::dataTableOutput("x1"),
    column(
      12,
      column(3,tags$div(title="forecast", numericInput("budget_input", label = ("Total Forecast"), value = 2))),
      column(2, textInput(inputId = "description", label = "Bookmark description", placeholder = "Data Summary")),
      column(2, bookmarkButton(id="bookmarkBtn"))),
    column(2, actionButton("opt_run", "Run")),
    DT::dataTableOutput("urlTable", width = "100%"),
    tags$style(type='text/css', "#bookmarkBtn { width:100%; margin-top: 25px;}")
  )
}

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

   con <- dbConnect(RSQLite::SQLite(), "bookmarks.db", overwrite = FALSE)
  myBookmarks <- reactiveValues(urlDF = NULL)

  observeEvent(input$bookmarkBtn, {
    session$doBookmark()
  })

  observeEvent(input$opt_run, {
    output$x1 = renderDT(df %>% mutate(Current  = as.numeric(Current)*(input$budget_input)), selection = 'none', editable = TRUE)
  })

  if(dbExistsTable(con, "Bookmarks")){
    tmpUrlDF <- data.table(dbReadTable(con, "Bookmarks"))
    myBookmarks$urlDF <- tmpUrlDF[, Timestamp := as.POSIXct(Timestamp, origin="1970-01-01 00:00")]
  } else {
    myBookmarks$urlDF <- NULL
  }

  session$onSessionEnded(function() {
    tmpUrlDF <- isolate({myBookmarks$urlDF})
    if(!is.null(tmpUrlDF)){
       dbWriteTable(con, "Bookmarks", tmpUrlDF, overwrite = TRUE)
    }
     dbDisconnect(con)
  })

  setBookmarkExclude(c("bookmarkBtn", "description", "urlTable_cell_clicked", "urlTable_rows_all", "urlTable_rows_current", "urlTable_rows_selected", "urlTable_search", "urlTable_state", "urlTable_row_last_clicked"))

  df <- data.table(Channel = c("A", "B","C"),
                   Current = c("2000", "3000","4000"),
                   Modified = c("2500", "3500","3000"),
                   New_Membership = c("450", "650","700"))

  output$x1 = renderDT(df, selection = 'none', editable = TRUE)

  onBookmarked(fun=function(url){
    if(!url %in% myBookmarks$urlDF$URL){
      if(is.null(myBookmarks$urlDF)){
        myBookmarks$urlDF <- unique(data.table(Description = input$description, URL = paste0("<a href='", url, "'>", url,"</a>"), Timestamp = Sys.time(), Session = session$token, User = Sys.getenv("USERNAME")), by="URL")
      } else {
        myBookmarks$urlDF <- unique(rbindlist(list(myBookmarks$urlDF, data.table(Description = input$description, URL = paste0("<a href='", url, "'>", url,"</a>"), Timestamp = Sys.time(), Session = session$token, User = Sys.getenv("USERNAME")))), by="URL")
      }
    }
  })

  output$urlTable = DT::renderDataTable({
    req(myBookmarks$urlDF)
    myBookmarks$urlDF[User %in% Sys.getenv("USERNAME")]
  }, escape=FALSE)

}
enableBookmarking(store = "url")
shinyApp(ui, server)

Answer 1

我的第一个直觉是您可能需要使用@AndrewTaylor建议的onRestore()。但是，在尝试运行代码后，很明显，只需修复代码中的反应性，即可解决此处的问题。

这是您的代码，进行了两个小修改：首先，对output $ x1进行了两次定义，因此我删除了第二个未使用任何反应性值的代码。其次，我将第一个输出$ x1移到了一个watchEvent之外，并使其仅在按下按钮时才触发。通常，您不应该在观察者内部定义输出，除非这是强制性的特殊情况，但是在此完成的方式会导致不正确的反应性。解决这个就是您所需要的。

此外，还需要加载DT和dplyr软件包以使代码完全可重现。

library(shiny)
library(RSQLite)
library(data.table)
library(DT)
library(dplyr)

ui <- function(request) {
  fluidPage(
    DT::dataTableOutput("x1"),
    column(
      12,
      column(3,tags$div(title="forecast", numericInput("budget_input", label = ("Total Forecast"), value = 2))),
      column(2, textInput(inputId = "description", label = "Bookmark description", placeholder = "Data Summary")),
      column(2, bookmarkButton(id="bookmarkBtn"))),
    column(2, actionButton("opt_run", "Run")),
    DT::dataTableOutput("urlTable", width = "100%"),
    tags$style(type='text/css', "#bookmarkBtn { width:100%; margin-top: 25px;}")
  )
}

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

  con <- dbConnect(RSQLite::SQLite(), "bookmarks.db", overwrite = FALSE)
  myBookmarks <- reactiveValues(urlDF = NULL)

  observeEvent(input$bookmarkBtn, {
    session$doBookmark()
  })

  observeEvent(input$opt_run, {
    cat('HJE')
  })

  output$x1 <- DT::renderDataTable({
    input$opt_run
    isolate({
      datatable(
        df %>% mutate(Current  = as.numeric(Current)*(input$budget_input)), selection = 'none', editable = TRUE
      )
    })
  })

  if(dbExistsTable(con, "Bookmarks")){
    tmpUrlDF <- data.table(dbReadTable(con, "Bookmarks"))
    myBookmarks$urlDF <- tmpUrlDF[, Timestamp := as.POSIXct(Timestamp, origin="1970-01-01 00:00")]
  } else {
    myBookmarks$urlDF <- NULL
  }

  session$onSessionEnded(function() {
    tmpUrlDF <- isolate({myBookmarks$urlDF})
    if(!is.null(tmpUrlDF)){
      dbWriteTable(con, "Bookmarks", tmpUrlDF, overwrite = TRUE)
    }
    dbDisconnect(con)
  })

  setBookmarkExclude(c("bookmarkBtn", "description", "urlTable_cell_clicked", "urlTable_rows_all", "urlTable_rows_current", "urlTable_rows_selected", "urlTable_search", "urlTable_state", "urlTable_row_last_clicked"))

  df <- data.table(Channel = c("A", "B","C"),
                   Current = c("2000", "3000","4000"),
                   Modified = c("2500", "3500","3000"),
                   New_Membership = c("450", "650","700"))

  onBookmarked(fun=function(url){
    if(!url %in% myBookmarks$urlDF$URL){
      if(is.null(myBookmarks$urlDF)){
        myBookmarks$urlDF <- unique(data.table(Description = input$description, URL = paste0("<a href='", url, "'>", url,"</a>"), Timestamp = Sys.time(), Session = session$token, User = Sys.getenv("USERNAME")), by="URL")
      } else {
        myBookmarks$urlDF <- unique(rbindlist(list(myBookmarks$urlDF, data.table(Description = input$description, URL = paste0("<a href='", url, "'>", url,"</a>"), Timestamp = Sys.time(), Session = session$token, User = Sys.getenv("USERNAME")))), by="URL")
      }
    }
  })

  output$urlTable = DT::renderDataTable({
    req(myBookmarks$urlDF)
    myBookmarks$urlDF[User %in% Sys.getenv("USERNAME")]
  }, escape=FALSE)

}
enableBookmarking(store = "url")
shinyApp(ui, server)