Fails to render dynamic contents of popover if it does not have a title.

[averissimo]

Describe the problem

Fails to render contents of popover if it does not have a title.

This only happens since shiny@1.4.0.

library(shiny)
ui <- bslib::page_fixed(
  theme = bslib::bs_theme("5"),
  bslib::card(class = "mt-5",
    bslib::card_header(
      bslib::tooltip(
        trigger = bslib::popover(
          trigger = shiny::icon("maximize"),
          id = "expbut",
          uiOutput("card_title"),
          uiOutput("card_yada")
        ),
        options = list(trigger = "hover"),
        class = "resize-button",
        "A tooltip"
      )
    ),
    "The card body..."
  )
)

server <- function(input, output) {
  default_slider_width <- reactiveVal(500)
  output$card_title <- renderUI({
    req(default_slider_width())
    shiny::tags$span("This is a new content")
  })
}

shiny::shinyApp(ui, server)

Session Info

Details

─ Session info ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
 setting  value
 version  R version 4.5.2 (2025-10-31)
 os       Ubuntu 26.04 LTS
 system   x86_64, linux-gnu
 ui       Positron
 language (EN)
 collate  en_US.UTF-8
 ctype    en_US.UTF-8
 tz       Europe/Lisbon
 date     2026-06-29
 pandoc   3.7.0.2 @ /usr/bin/pandoc
 quarto   1.6.42 @ /opt/quarto/bin/quarto
─ Packages ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

! package     * version     date (UTC) lib source

bslib         0.11.0.9000 2026-06-29 [1] Github (rstudio/bslib@c87abc5)

P cachem        1.1.0       2024-05-16 [?] CRAN (R 4.5.0)

cli           3.6.6       2026-04-09 [1] CRAN (R 4.5.2)

devtools      2.5.2       2026-04-30 [1] CRAN (R 4.5.2)

P digest        0.6.39      2025-11-19 [?] CRAN (R 4.5.2)

ellipsis      0.3.3       2026-04-04 [1] CRAN (R 4.5.2)

P fastmap       1.2.0       2024-05-15 [?] CRAN (R 4.5.0)

P fontawesome   0.5.3       2024-11-16 [?] CRAN (R 4.5.0)

fs            2.1.0       2026-04-18 [1] CRAN (R 4.5.2)

glue          1.8.1       2026-04-17 [1] CRAN (R 4.5.2)

P htmltools     0.5.9       2025-12-04 [?] CRAN (R 4.5.2)

P httpuv        1.6.17      2026-03-18 [?] CRAN (R 4.5.2)

P jquerylib     0.1.4       2021-04-26 [?] CRAN (R 4.5.0)

P jsonlite      2.0.0       2025-03-27 [?] CRAN (R 4.5.0)

P later         1.4.8       2026-03-05 [?] CRAN (R 4.5.2)

P lifecycle     1.0.5       2026-01-08 [?] CRAN (R 4.5.2)

P magrittr      2.0.5       2026-04-04 [?] CRAN (R 4.5.2)

P memoise       2.0.1       2021-11-26 [?] CRAN (R 4.5.0)

P mime          0.13        2025-03-17 [?] CRAN (R 4.5.0)

P otel          0.2.0       2025-08-29 [?] CRAN (R 4.5.2)

P pillar        1.11.1      2025-09-17 [?] CRAN (R 4.5.1)

P pkgbuild      1.4.8       2025-05-26 [?] CRAN (R 4.5.0)

P pkgconfig     2.0.3       2019-09-22 [?] CRAN (R 4.5.0)

pkgload       1.5.3       2026-06-15 [1] CRAN (R 4.5.2)

P promises      1.5.0       2025-11-01 [?] CRAN (R 4.5.2)

purrr         1.2.2       2026-04-10 [1] CRAN (R 4.5.2)

P R6            2.6.1       2025-02-15 [?] CRAN (R 4.5.0)

Rcpp          1.1.1-1.1   2026-04-24 [1] CRAN (R 4.5.2)

renv          1.2.3       2026-05-16 [1] CRAN (R 4.5.2)

P rlang         1.2.0       2026-04-06 [?] CRAN (R 4.5.2)

P sass          0.4.10      2025-04-11 [?] CRAN (R 4.5.0)

sessioninfo   1.2.4       2026-06-04 [1] CRAN (R 4.5.2)

shiny       * 1.14.0      2026-06-21 [1] CRAN (R 4.5.2)

P tibble        3.3.1       2026-01-11 [?] CRAN (R 4.5.2)

usethis       3.2.1       2025-09-06 [1] CRAN (R 4.5.2)

vctrs         0.7.3       2026-04-11 [1] CRAN (R 4.5.2)

withr         3.0.3       2026-06-19 [1] CRAN (R 4.5.2)

P xtable        1.8-8       2026-02-22 [?] CRAN (R 4.5.2)
[1] /home/averissimo/.cache/R/renv/library/teal.widgets-ccbacd7b/linux-ubuntu-resolute/R-4.5/x86_64-pc-linux-gnu

[2] /home/averissimo/.cache/R/renv/sandbox/linux-ubuntu-resolute/R-4.5/x86_64-pc-linux-gnu/9a444a72

── Packages attached to the search path.

P ── Loaded and on-disk path mismatch.

──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

[gadenbuie]

Thanks @averissimo, I can reproduce the issue and confirm that the change the happened somewhere in the shiny v1.14.0 release.

Here's a more targeted reprex that also removes the tooltip():

Details

library(shiny)
library(bslib)

POPOVER_TITLE <- TRUE

tooltip_popover <- function(id) {
  ns <- NS(id)
  popover(
    id = ns("foo"),
    title = if (POPOVER_TITLE) "Popover Title" else NULL,
    icon("maximize"),
    uiOutput(ns("ui"))
  )
}

tooltip_popover_server <- function(id) {
  moduleServer(id, function(input, output, session) {
    output$ui <- renderUI({
      span("Hello from the popover!")
    })
  })
}

ui <- page_fillable(
  class = "p-5",
  div(
    tooltip_popover("bare"),
  ),
  card(
    card_header(
      tooltip_popover("card")
    ),
    p(
      "Popover title is",
      sprintf("%s.", if (POPOVER_TITLE) "enabled" else "disabled")
    ),
    verbatimTextOutput("debug"),
  )
)

server <- function(input, output) {
  tooltip_popover_server("bare")
  tooltip_popover_server("card")

  output$debug <- renderPrint({
    list(
      shiny = paste(packageVersion("shiny")),
      bslib = paste(packageVersion("bslib"))
    )
  })
}

shiny::shinyApp(ui, server)

Shiny	With Title	No Title
0.13.0
0.14.0

[gadenbuie]

git bisect narrows down the source of the problem to rstudio/shiny#4388

[gadenbuie]

Thanks again for the clear reprex, @averissimo — this was very helpful for tracking it down.

We've confirmed the root cause: it's a regression in shiny (introduced by rstudio/shiny#4388, which is why it appears in shiny 1.14.0). When an output is rendered inside a display:contents wrapper — which is how popover()/tooltip() wrap their contents — shiny's IntersectionObserver ends up observing a boxless element and never detects when the output becomes visible, so the server keeps it suspended and it renders nothing. The reason a title "fixes" it is incidental: a titled popover has enough width that a different observer (a ResizeObserver) happens to fire instead.

I've opened an upstream issue with the full analysis and a proposed fix: rstudio/shiny#4406

In the meantime, you can work around it locally by giving the output a minimal width so the observer fires — for example:

uiOutput(ns("ui"), style = "min-width: 1px")

(or adding a title to the popover, if that suits your design).

We'll also land a small temporary fix in bslib so this works without the workaround, and we'll remove it once the upstream shiny fix ships.

[averissimo]

Thanks @gadenbuie for the quick feedback and fix instructions

I did something similar to temporarily fix it and will look forward an upstream fix from shiny!