Question

I am creating a Shiny app that displays data.frame information at the top of the screen and specific variable stats at the bottom. The user can navigate the data.frame columns by interacting with a DT::datatable object.

When a user clicks on a variable, detailed information is presented that can be edited. I would like this information to be updated and reflected in the datatable. My problem is that when I update the table, it is rendered and shown starting at the very beginning. How can I preserve the page and row selection of the datatable after making edits?

Here is a minimal working example that shows the mtcars dataset in a DT::datatable. I have some controls that update fields. Notice that datatable is re-rendered back to the first page.

library(shiny)

runApp(shinyApp(

  ui = fluidPage(
    title = "minimal-working-example",
    fluidRow(
      column(3, inputPanel(
        selectInput("field", "Field", choices = names(mtcars)),
        numericInput("value", "Value", 0),
        actionButton("submit", "Submit")
      )),

      column(9,
        DT::dataTableOutput("table")
      )
    )
  ),

  server = function(input, output) {

    v <- reactiveValues(mtcars=mtcars)

    observeEvent(input$submit, {
      v$mtcars[input$field] <- input$value
    })

    output$table <- DT::renderDataTable({
      DT::datatable(
        v$mtcars,
        selection = "single",
        options = list(pageLength = 5))
    })
  }
))

Session Info:

Session info --------------------------
 setting  value                       
 version  R version 3.3.0 (2016-05-03)
 system   x86_64, mingw32             
 ui       RStudio (0.99.902)          
 language (EN)                        
 collate  English_United States.1252  
 tz       America/Chicago             
 date     2016-07-11                  

Packages -------------------------------
 package     * version     date       source                        
 DT            0.1.45      2016-02-09 Github (rstudio/DT@a63e9ac)   
 shiny       * 0.13.0.9000 2016-02-08 Github (rstudio/shiny@e871934)

Answer 1

这可以从R内部完成，而不通过JS进入datatable的结构或类似的东西。

我们利用从DT包中获取的各种表状态信息来呈现新的更新datatable，就像之前一样。我们使用的所有内容都在this DT documentation中描述。

第一项：选择。您可以通过在数据表的selected = ...参数内添加selection来预先选择行。这可以与变量input$table_rows_selected组合以保存先前选择的行，并在重新渲染时预先选择该确切的行。

第二项：Page。 datatable包有一个选项displayStart，用于指定在呈现表时应首先显示哪一行。 Documentation here.因此，如果每页有5行，displayStart = 9将在第3页开始显示。（JavaScript数组从0开始，因此总是减1）。这可以与{{1}结合使用这是当前可见行号的向量。如果我们存储第一个条目（减1），我们知道从哪里开始显示。

下面的完整代码示例：

input$table_rows_current

Update row(s) of a Shiny DataTable while maintaining position

1 个答案: