scroll bars do not appear when renderDataTable is used in flexdashboard

[nitingupta2]

Quite possibly a bug - not sure whether in DT or flexdashboard.

Here's the problem: I'm rendering a datatable in a shiny flexdashboard app in a reactive context, so that it updates when an input in changed. My dataset isn't large enough to use pagination, so the user should be able to scroll in Y direction to see all records. However, scroll bars do not appear when the table is updated in renderDataTable.

This issue has been asked on StackOverflow here without a satisfactory resolution.

Here's how the problem can be reproduced within a simple shiny flexdashboard Rmd file. In comparison, the scroll bars appear in renderTable as expected. Similarly, datatable also works as expected when used in a non-reactive context with a fixed input.

To be sure, I have tried both the current CRAN and development versions of DT and flexdashboard without success.

---
title: "Test Flexboard Shiny App"
runtime: shiny
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
---

```{r setup, include=FALSE}
library(flexdashboard)
library(shiny)
library(shinythemes)
library(DT)
library(tidyverse)

Sidebar {.sidebar}

selectInput("data_set", "Pick a dataset", choices = c("mtcars","airquality"), selected = "mtcars")

# Input dataset
mydataset <- reactive({

  name <- input$data_set
  df <- switch(name,
               "mtcars" = mtcars,
               "airquality" = airquality)

  return(df)
})

Column {data-width=500}

renderTable (reactive)

renderTable(mydataset(), rownames = TRUE)

Column {data-width=500}

renderDataTable (reactive)

DT::renderDataTable(datatable(mydataset(), rownames = TRUE,
                              options = list(bPaginate = FALSE, searching = FALSE, info = FALSE)))

datatable (fixed input)

datatable(mtcars, rownames = TRUE, 
          options = list(bPaginate = FALSE, searching = FALSE, info = FALSE))

``` r
xfun::session_info()
#> R version 3.6.3 (2020-02-29)
#> Platform: x86_64-w64-mingw32/x64 (64-bit)
#> Running under: Windows 10 x64 (build 18362)
#> 
#> Locale:
#>   LC_COLLATE=English_United States.1252 
#>   LC_CTYPE=English_United States.1252   
#>   LC_MONETARY=English_United States.1252
#>   LC_NUMERIC=C                          
#>   LC_TIME=English_United States.1252    
#> 
#> Package version:
#>   askpass_1.1              assertthat_0.2.1         backports_1.1.7         
#>   base64enc_0.1.3          BH_1.72.0.3              blob_1.2.1              
#>   broom_0.5.6              callr_3.4.3              cellranger_1.1.0        
#>   cli_2.0.2                clipr_0.7.0              colorspace_1.4-1        
#>   compiler_3.6.3           crayon_1.3.4             crosstalk_1.1.0.1       
#>   curl_4.3                 DBI_1.1.0                dbplyr_1.4.4            
#>   desc_1.2.0               digest_0.6.25            dplyr_1.0.0             
#>   DT_0.13.4                ellipsis_0.3.1           evaluate_0.14           
#>   fansi_0.4.1              farver_2.0.3             fastmap_1.0.1           
#>   flexdashboard_0.5.1.9000 forcats_0.5.0            fs_1.4.1                
#>   generics_0.0.2           ggplot2_3.3.1            glue_1.4.1              
#>   graphics_3.6.3           grDevices_3.6.3          grid_3.6.3              
#>   gtable_0.3.0             haven_2.3.1              highr_0.8               
#>   hms_0.5.3                htmltools_0.4.0          htmlwidgets_1.5.1.9001  
#>   httpuv_1.5.4             httr_1.4.1               isoband_0.2.1           
#>   jsonlite_1.6.1           knitr_1.28               labeling_0.3            
#>   later_1.1.0.1            lattice_0.20-41          lazyeval_0.2.2          
#>   lifecycle_0.2.0          lubridate_1.7.9          magrittr_1.5            
#>   markdown_1.1             MASS_7.3.51.6            Matrix_1.2.18           
#>   methods_3.6.3            mgcv_1.8.31              mime_0.9                
#>   modelr_0.1.8             munsell_0.5.0            nlme_3.1-148            
#>   openssl_1.4.1            pillar_1.4.4             pkgbuild_1.0.8          
#>   pkgconfig_2.0.3          pkgload_1.1.0            plyr_1.8.6              
#>   praise_1.0.0             prettyunits_1.1.1        processx_3.4.2          
#>   progress_1.2.2           promises_1.1.0           ps_1.3.3                
#>   purrr_0.3.4              R6_2.4.1                 RColorBrewer_1.1.2      
#>   Rcpp_1.0.4.6             readr_1.3.1              readxl_1.3.1            
#>   rematch_1.0.1            reprex_0.3.0             reshape2_1.4.4          
#>   rlang_0.4.6              rmarkdown_2.2            rprojroot_1.3.2         
#>   rstudioapi_0.11          rvest_0.3.5              scales_1.1.1            
#>   selectr_0.4.2            shiny_1.4.0.2            shinythemes_1.1.2       
#>   sourcetools_0.1.7        splines_3.6.3            stats_3.6.3             
#>   stringi_1.4.6            stringr_1.4.0            sys_3.3                 
#>   testthat_2.3.2           tibble_3.0.1             tidyr_1.1.0             
#>   tidyselect_1.1.0         tidyverse_1.3.0          tinytex_0.23            
#>   tools_3.6.3              utf8_1.1.4               utils_3.6.3             
#>   vctrs_0.3.1              viridisLite_0.3.0        whisker_0.4             
#>   withr_2.2.0              xfun_0.14                xml2_1.3.2              
#>   xtable_1.8-4             yaml_2.2.1

^{Created on 2020-06-08 by the reprex package (v0.3.0)}

---

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[AnachronicNomad]

I can confirm that this is an ongoing issue; including after the most recent release 17 days ago.

> xfun::session_info('DT')
R version 4.0.2 (2020-06-22)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.5 LTS, RStudio 1.3.959

Locale:
  LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
  LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=en_US.UTF-8       LC_NAME=C                 
  LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

Package version:
  base64enc_0.1.3   BH_1.72.0.3       crosstalk_1.1.0.1 digest_0.6.25     DT_0.15.4         graphics_4.0.2   
  grDevices_4.0.2   htmltools_0.5.0   htmlwidgets_1.5.1 jsonlite_1.7.0    later_1.1.0.1     lazyeval_0.2.2   
  magrittr_1.5      methods_4.0.2     promises_1.1.1    R6_2.4.1          Rcpp_1.0.5        rlang_0.4.7      
  stats_4.0.2       utils_4.0.2       yaml_2.2.1       
> 

[nitingupta2]

Would appreciate if a package maintainer could comment whether this issue is under review.

Thank you.

[shrektan]

Thanks for reporting this issue. I can confirm it. I'm investigating this now...

[shrektan]

OK, adding fillContainer = TRUE to datatable() will resolve this. (Ref to #243)

Here're some facts:

• The datatables javascript library lacks the ability to become scrollable on Y axis automatically (it has scrollY option, but it needs to be specified in advance). This should be the reason of PR #243.

• The reason of using datatable() directly in flexdashboard works while renderDT() not is the fillContainer param is enabled by default in the former cases.

So we'd better enable fillContainer for renderDT() in Flexdashboard automatically.

---

@nitingupta2 As of your problem, I mean changing the chunk as below will be enough :

### renderDataTable (reactive)

```{r}

DT::renderDataTable(datatable(mydataset(), rownames = TRUE,
                              options = list(bPaginate = FALSE, searching = FALSE, info = FALSE),
                              fillContainer = TRUE))

[shrektan]

Well, now it looks like an issue of FlexDashboard to me, as the fillContainer option should be enable there:

https://github.com/rstudio/flexdashboard/blob/6ad5aceb16b07850535786c45a0e55f114f4d2d7/R/flex_dashboard.R#L189-L194

However, under Shiny mode, these lines will fail to work, apparently.

So I will file an issue on FlexDashboard.