download edited data table gives warning in shiny app

问题

Here is an example shiny app that allows user to download editable table. User can click on the csv button on the upper left corner to download the table.

However, I found after I edit any cell in the table (by double click on any cell and modify contents), when I click on the csv button, enter file name and save, I got warning message like below:

dataTables warning: table id=DataTables_Table_3 - invalid json response. 
For more information about this error, please see http://datatables.net/tn/1

Although I was still able to save the table as csv file, the warning message is very annoying.

This only happens after I add the argument server=FALSE in the renderDT function. The reason I need server=FALSE is without this, the app only download the first page of the folder (missing all the rest of data after saving).

Another problem is after I edit a cell, if I check/uncheck some columns, the editted cell goes back to its original value.

Does anyone know how to fix these issues?

Thanks a lot.

The example shiny app is below:

library(shiny)
library(DT)
library(dplyr)

shinyApp(
    # UI
    ui = fluidPage(DT::dataTableOutput('tbl'),
                   checkboxGroupInput('datacols', 
                                      label='Select Columns:',
                                      choices= c('Sepal.Length', 'Sepal.Width', 'Petal.Length', 'Petal.Width', 'Specie'),
                                      selected = c('Sepal.Length', 'Sepal.Width', 'Petal.Length', 'Petal.Width', 'Specie'),
                                      inline=TRUE )

                   ),

    # SERVER
    server = function(input, output) {



        df = reactiveValues()

        observe ({

            df$dat = iris %>% select(one_of(input$datacols))
        })
        # render DT
        output$tbl = renderDT(server=FALSE, {
                datatable(df$dat,
                editable = "cell",
                extensions = "Buttons",
                options = list(
                    dom = "Bfrtip", buttons = list("csv")))

        })


        observeEvent(input[["tbl_cell_edit"]], {
            cellinfo <- input[["tbl_cell_edit"]]
            df$dat  <- editData(df$dat,  input[["tbl_cell_edit"]], "tbl")
        })

    }
)

回答1:

That's because you're using the proxy with server = FALSE. You should not. Do

observeEvent(input[["tbl_cell_edit"]], {
  cellinfo <- input[["tbl_cell_edit"]]
  df$dat <- editData(df$dat,  input[["tbl_cell_edit"]])
})

and not

observeEvent(input[["tbl_cell_edit"]], {
  cellinfo <- input[["tbl_cell_edit"]]
  df$dat <- editData(df$dat,  input[["tbl_cell_edit"]], "tbl")
})

If you want to download the whole table with server = TRUE, see this discussion.

来源：https://stackoverflow.com/questions/58176637/download-edited-data-table-gives-warning-in-shiny-app

标签

Shiny