numericInput() returns 0 instead of NA

[hcstubbe]

When using the latest version of R (4.2.0 or 4.2.1, both on Windows 11 or Ubuntu 20.04.4 LTS), the numericInput() returns 0 instead of NA, when no value or a string are entered, if DT::renderDT() is used to render a table.

I also referenced this problem here.

System details

Output of sessionInfo() (Windows 11 and Ubuntu 20.04.4 LTS):

Ubuntu 20.04.4 LTS:

R version 4.2.0 (2022-04-22)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 20.04.4 LTS

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/liblapack.so.3

locale:
 [1] 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   
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] shiny_1.7.1 lcarsc_0.2 

loaded via a namespace (and not attached):
 [1] whoami_1.3.0         fs_1.5.2             xopen_1.0.0          usethis_2.1.6        lubridate_1.8.0      fontawesome_0.2.2    devtools_2.4.3       bit64_4.0.5         
 [9] httr_1.4.3           rprojroot_2.0.3      tools_4.2.0          bslib_0.3.1          utf8_1.2.2           R6_2.5.1             DT_0.23              DBI_1.1.3           
[17] withr_2.5.0          tidyselect_1.1.2     prettyunits_1.1.1    shinyvalidate_0.1.2  processx_3.7.0       rematch_1.0.1        bit_4.0.4            curl_4.3.2          
[25] compiler_4.2.0       cli_3.3.0            xml2_1.3.3           shinyjs_2.1.0        desc_1.4.1           sass_0.4.1           readr_2.1.2          callr_3.7.1         
[33] rappdirs_0.3.3       stringr_1.4.0        digest_0.6.29        pkgconfig_2.0.3      htmltools_0.5.2      sessioninfo_1.2.2    attempt_0.3.1        fastmap_1.1.0       
[41] htmlwidgets_1.5.4    rlang_1.0.4          RMariaDB_1.2.2       rstudioapi_0.13      RSQLite_2.2.14       jquerylib_0.1.4      generics_0.1.3       jsonlite_1.8.0      
[49] crosstalk_1.2.0      dplyr_1.0.9          config_0.3.1         magrittr_2.0.3       Rcpp_1.0.9           fansi_1.0.3          lifecycle_1.0.1      stringi_1.7.8       
[57] yaml_2.3.5           brio_1.1.3           pkgbuild_1.3.1       blob_1.2.3           promises_1.2.0.1     shinydashboard_0.7.2 crayon_1.5.1         rhub_1.1.1          
[65] hms_1.1.1            knitr_1.39           parsedate_1.3.0      ps_1.7.1             pillar_1.7.0         uuid_1.1-0           pkgload_1.3.0        glue_1.6.2          
[73] golem_0.3.3          pool_0.1.6           remotes_2.4.2        fmsb_0.7.3           vctrs_0.4.1          tzdb_0.3.0           httpuv_1.6.5         testthat_3.1.4      
[81] purrr_0.3.4          rcmdcheck_1.4.0      assertthat_0.2.1     cachem_1.0.6         xfun_0.31            mime_0.12            xtable_1.8-4         roxygen2_7.2.0      
[89] later_1.3.0          tibble_3.1.7         memoise_2.0.1        shinyWidgets_0.7.1   ellipsis_0.3.2    

Windows 11:

R version 4.2.1 (2022-06-23 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 22000)

Matrix products: default

locale:
[1] LC_COLLATE=German_Germany.utf8  LC_CTYPE=German_Germany.utf8    LC_MONETARY=German_Germany.utf8 LC_NUMERIC=C                    LC_TIME=German_Germany.utf8    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] DT_0.23     shiny_1.7.1

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.9        digest_0.6.29     later_1.3.0       mime_0.12         R6_2.5.1          jsonlite_1.8.0    lifecycle_1.0.1   xtable_1.8-4     
 [9] magrittr_2.0.3    cachem_1.0.6      rlang_1.0.3       promises_1.2.0.1  jquerylib_0.1.4   bslib_0.4.0       ellipsis_0.3.2    tools_4.2.1      
[17] htmlwidgets_1.5.4 crosstalk_1.2.0   yaml_2.3.5        httpuv_1.6.5      fastmap_1.1.0     compiler_4.2.1    memoise_2.0.1     htmltools_0.5.2  
[25] sass_0.4.1   

Example application

After launching the application delete the input or enter a character.

if (interactive()) {
library(shiny)
library(DT)
ui <- fluidPage(
    numericInput("obs", "Observations:", 10, min = 1, max = 100),
    verbatimTextOutput("value"),
    DT::dataTableOutput("responses_table")
)
server <- function(input, output) {
    output$value <- renderText({ input$obs })
    
    output$responses_table <- DT::renderDT({
        isolate(DT::datatable(iris)
        )
    })
    
}
shinyApp(ui, server)
}

Describe the problem in detail

When using the latest version of R (4.2.0 or 4.2.1, both on Windows 11 or Ubuntu 20.04.4 LTS), the numericInput() returns 0 instead of NA, when no value or a string are entered, if DT::renderDT() is used to render a table. I tested this for the latest R version (4.2.0 and 4.2.1) and on Ubuntu and Windows (see above). This problem is absent in older R versions (e.g. R version 4.1.2). In a data app, where empty values need to be represented as NA, this is a huge problem.

[jcheng5]

Thanks for the report. Some clarifying questions:

1. When you say it's 0 instead of NA, do you mean that 0 is shown in verbatimTextOutput("value")?
2. If you remove the DT from the app, does it change the behavior of the text output?

[hcstubbe]

Hi, thank you for getting back to me!

1. input$obs returns 0 instead of NA. Therefore, 0 is shown instead of NA in verbatimTextOutput("value").
2. If I remove DT from the app, the problem disappears: input$obs can return NA again.

EDIT:
simply adding DT::datatable(iris) to the ui changes the behavior of the numericInput() (the code is the example from ?numericInput ):

## Only run examples in interactive R sessions
if (interactive()) {
    
    ui <- fluidPage(
        numericInput("obs", "Observations:", 10, min = 1, max = 100),
        verbatimTextOutput("value"),
        DT::datatable(iris)  # This line changes the behavior of numericInput()
    )
    server <- function(input, output) {
        output$value <- renderText({ input$obs })
    }
    shinyApp(ui, server)
}

[jcheng5]

Wow, confirmed on Windows 10, R 4.2.0. Exactly as you said--without the DT, no issue. And it doesn't happen on macOS R 4.1.2. What in the world??

[jcheng5]

OK, mystery solved. It's an issue in DT that has since been fixed, but not yet released on CRAN. If you remotes::install_github("rstudio/DT"), you should be good.