SharedData objects do not "select" properly when data has one row

[yogat3ch]

Hi @cpsievert & crosstalk devs, I've recently just realized that the selection is not updated properly when the data only has a single row.

A reprex is below:

# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(crosstalk)
library(shiny)


# Define UI for application that draws a histogram
ui <- fluidPage(
  
  # Application title
  titlePanel("Old Faithful Geyser Data"),
  
  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(
      actionButton(
        "send",
        label = "Send"
      )
    ),
    
    # Show a plot of the generated distribution
    mainPanel(
      DT::DTOutput("distPlot")
    )
  )
)

# Define server logic required to draw a histogram
server <- function(input, output) {
  
  isolate({
    s_data <- crosstalk::SharedData$new(data = mtcars |> head(1))
  })
  output$distPlot <- DT::renderDT({
    # generate bins based on input$bins from ui.R
    DT::datatable(s_data)
  }, server = FALSE)
  observeEvent(input$send,{
    o <- s_data$data(withSelection = TRUE)
    #selected_ should be TRUE
    if (isFALSE(o$selected_))
      browser()
    
  })
}

# Run the application
shinyApp(ui = ui, server = server)

If one selects the row, presses the send button, and checks the o object, the selected_ column has FALSE for the only value even though the row is selected. Add two rows to the data and it works fine. (head(2))

sessionInfo

``` R version 4.1.3 (2022-03-10) Platform: aarch64-apple-darwin20 (64-bit) Running under: macOS Monterey 12.3.1

Matrix products: default LAPACK: /Library/Frameworks/R.framework/Versions/4.1-arm64/Resources/lib/libRlapack.dylib

locale: [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

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

other attached packages: [1] crosstalk_1.2.0.9000 shiny_1.7.1

loaded via a namespace (and not attached): [1] fs_1.5.2 reactable_0.2.3.9000 usethis_2.1.5 lubridate_1.8.0 devtools_2.4.3
[6] httr_1.4.3 rprojroot_2.0.3 echarty_1.4.5 BOR_0.0.0.9000 tippy_1.0.0
[11] tools_4.1.3 bslib_0.3.1 utf8_1.2.2 R6_2.5.1 DT_0.22.1
[16] DBI_1.1.2 lazyeval_0.2.2 colorspace_2.0-3 withr_2.5.0 tidyselect_1.1.2
[21] prettyunits_1.1.1 shinyvalidate_0.1.2 processx_3.5.2 compiler_4.1.3 english_1.2-6
[26] cli_3.3.0 xml2_1.3.3 shinyjs_2.1.0 desc_1.4.1 plotly_4.10.0
[31] sass_0.4.0 scales_1.1.1 bs4Dash_2.0.3 callr_3.7.0 crssDB_0.0.0.9200
[36] stringr_1.4.0 digest_0.6.29 rmarkdown_2.13 pkgconfig_2.0.3 htmltools_0.5.2
[41] sessioninfo_1.2.2 attempt_0.3.1 learnr_0.10.1 fastmap_1.1.0 htmlwidgets_1.5.4
[46] rlang_1.0.2 rstudioapi_0.13 jquerylib_0.1.4 generics_0.1.2 jsonlite_1.8.0
[51] dplyr_1.0.9 config_0.3.1 magrittr_2.0.3 patchwork_1.1.1 Rcpp_1.0.8.3
[56] munsell_0.5.0 fansi_1.0.3 lifecycle_1.0.1 stringi_1.7.6 yaml_2.3.5
[61] snakecase_0.11.0 brio_1.1.3 pkgbuild_1.3.1 plyr_1.8.7 grid_4.1.3
[66] promises_1.2.0.1 crayon_1.5.1 knitr_1.37 ps_1.6.0 pillar_1.7.0
[71] markdown_1.1 pkgload_1.2.4 glue_1.6.2 evaluate_0.15 cicerone_1.0.4
[76] golem_0.3.1 data.table_1.14.2 remotes_2.4.2 renv_0.15.4 vctrs_0.4.1
[81] httpuv_1.6.5 testthat_3.1.2 virgaUtils_0.0.0.9001 gtable_0.3.0 purrr_0.3.4
[86] tidyr_1.2.0 assertthat_0.2.1 cachem_1.0.6 ggplot2_3.3.5 xfun_0.29
[91] mime_0.12 xtable_1.8-4 UU_0.0.0.9006 roxygen2_7.1.2 later_1.3.0
[96] viridisLite_0.4.0 dockerfiler_0.1.4 tibble_3.1.7 memoise_2.0.1 shinyWidgets_0.6.4
[101] sortable_0.4.5 ellipsis_0.3.2

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