从R Shiny Datatable中提取过滤器 [英] Extract filters from R Shiny Datatable

问题描述

我在R Shiny中有一个 DT数据表，并且通过设置< renderDT（）中的code> filter = top 。现在，我想提取用户应用的过滤器，以便将它们保存在服务器端变量中，并在（例如）数据库更新，需要更新表时重新应用它们。

I have a DT data table in R Shiny and I have enabled column filtering by setting filter="top" within renderDT(). I now want to extract the user-applied filters so I can save them in variables server-side and reapply them when -- for instance -- a database is updated, requiring an update of the table.

这里是使用Shiny Dashboard的MWE：

Here's a MWE using Shiny Dashboard:

library(shiny)           #  Shiny web app
library(shinydashboard)  #  Dashboard framework for Shiny
library(plotly)          #  Plotly interactive plots
library(DT)

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(
    fluidRow(column(12, DTOutput("table")))
  )
)

server <- function(input, output, session) {
  fileData <- reactiveFileReader(1000, session, 'test.csv', read.csv)
  output$table <- renderDT(fileData(), filter = "top")
}

shinyApp(ui, server)

重申一下，我想保存过滤器（例如，用户可以选择一个数值范围s或来自其中一个过滤器框的特定因子）作为 input $ 变量，以便可以在服务器端使用它们。

To reiterate, I'd like to save the filters (for instance, a user might select a range of numeric values or a specific factor from one of the filter boxes) as input$ variables so I can use them on the server side.

推荐答案

我认为最简单的方法是添加

I think the simplest way to do this is to just add

options = list(stateSave = TRUE)

在 renderDT（）内部函数。然后，在服务器内，可以随时通过 input $< tableID> _state （我的表仅被称为表，因此它变为 input $ table_state ：

inside the renderDT() function. Then, within the server, the state of the table can be accessed at any time with input$<tableID>_state (my table is just called "table" so this becomes input$table_state:

observeEvent(input$table_state, {
  str(input$table_state)
})

然后整个解决方案是：

The whole solution is then:

library(shiny)
library(shinydashboard)
library(plotly)
library(DT)

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(
    box(DTOutput("table"))
  )
)

server <- function(input, output, session) {
  fileData <- reactiveFileReader(1000, session, 'www/test.csv', read.csv)
  output$table <- renderDT(fileData(), filter = "top",
    options = list(stateSave = TRUE))

  observeEvent(input$table_state, {
    str(input$table_state)
  })

}

shinyApp(ui, server)

RStudio控制台中的示例输出：

Sample output within the RStudio console:

List of 6
 $ time   : num 1.54e+12
 $ start  : int 0
 $ length : int 10
 $ order  : list()
 $ search :List of 4
  ..$ search         : chr ""
  ..$ smart          : logi TRUE
  ..$ regex          : logi FALSE
  ..$ caseInsensitive: logi TRUE
 $ columns:List of 5
  ..$ :List of 2
  .. ..$ visible: logi TRUE
  .. ..$ search :List of 4
  .. .. ..$ search         : chr ""
  .. .. ..$ smart          : logi TRUE
  .. .. ..$ regex          : logi FALSE
  .. .. ..$ caseInsensitive: logi TRUE
  ..$ :List of 2
  .. ..$ visible: logi TRUE
  .. ..$ search :List of 4
  .. .. ..$ search         : chr "[\"0\"]"
  .. .. ..$ smart          : logi TRUE
  .. .. ..$ regex          : logi FALSE
  .. .. ..$ caseInsensitive: logi TRUE
  ..$ :List of 2
  .. ..$ visible: logi TRUE
  .. ..$ search :List of 4
  .. .. ..$ search         : chr "[\"8\"]"
  .. .. ..$ smart          : logi TRUE
  .. .. ..$ regex          : logi FALSE
  .. .. ..$ caseInsensitive: logi TRUE
  ..$ :List of 2
  .. ..$ visible: logi TRUE
  .. ..$ search :List of 4
  .. .. ..$ search         : chr ""
  .. .. ..$ smart          : logi TRUE
  .. .. ..$ regex          : logi FALSE
  .. .. ..$ caseInsensitive: logi TRUE
  ..$ :List of 2
  .. ..$ visible: logi TRUE
  .. ..$ search :List of 4
  .. .. ..$ search         : chr ""
  .. .. ..$ smart          : logi TRUE
  .. .. ..$ regex          : logi FALSE
  .. .. ..$ caseInsensitive: logi TRUE

请注意搜索列表，其中显示了应用于各列的过滤器。

Note the search lists which show the filters applied to each column.

对于超级简单的过滤器提取，请使用 input $ table_search_columns 。产生与使用 sapply 相同的结果：

For super-easy filter extraction, use input$table_search_columns. This gives the same result as using sapply:

sapply(input$table_state$columns, function(x) x$search$search)

这将给出类似的内容

[1] ""        "[\"0\"]" "[\"8\"]" ""        ""      

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