Question

我正在尝试在R Shiny应用程序中使用书签，并将书签保存在表中。第一步，我想将它们保存在本地，并在每次加载此应用程序时检索它们。然后将它们保存在数据库中。这是添加书签并将其保存在表上的代码。书签从现在开始在从已保存的RDS中读取的地方起作用。

在URL上使用shinyapps.io做书签也可以将书签保存到AWS上的数据库中。

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

ui <- function(request) {
  fluidPage(
    plotOutput("plot"),
    sliderInput("n", "Number of observations", 1, nrow(faithful), 100),
    fluidRow(column(2, textInput(inputId = "description", label = "Bookmark description", placeholder = "Data Summary")), column(2, bookmarkButton(id="bookmarkBtn"))),
    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()
  })
  #
  # 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"))

  output$plot <- renderPlot({
    hist(faithful$eruptions[seq_len(input$n)], breaks = 40)
  })

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

  output$urlTable = DT::renderDataTable({
    #read_rds("bookmarks.rds")
    myBookmarks$urlDF
    write_rds(myBookmarks$urlDF, "bookmark.rds")
  }, escape=FALSE)

}

enableBookmarking(store = "url")
shinyApp(ui, server)
#> PhantomJS not found. You can install it with webshot::install_phantomjs(). If it is installed, please make sure the phantomjs executable can be found via the PATH variable.

静态R Markdown文档中不支持发光的应用程序

^{由reprex package（v0.2.1.9000）于2019-01-29创建}

Answer 1

这是使用saveRDS()代替sqlite代替我以前的answer的另一种方法：

编辑：添加了用户名检查。

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

ui <- function(request) {
  fluidPage(
    plotOutput("plot"),
    sliderInput("n", "Number of observations", 1, nrow(faithful), 100),
    fluidRow(column(2, textInput(inputId = "description", label = "Bookmark description", placeholder = "Data Summary")), column(2, bookmarkButton(id="bookmarkBtn"))),
    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()
  })

  # 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
  # }

  if(file.exists("bookmarks.rds")){
    myBookmarks$urlDF <- readRDS("bookmarks.rds")
  } else {
    myBookmarks$urlDF <- NULL
  }

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

  output$plot <- renderPlot({
    hist(faithful$eruptions[seq_len(input$n)], breaks = 40)
  })

  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)

在R Shiny中添加书签并保存书签

1 个答案: