renderText not working in headers

[jy-r]

Expected behavior

• changing input will change the result in header

Actual behavior

• following code worked in previous versions of R and flexdashboard, but in current stopped working
• not working in
  • R version 3.6.1 (2019-07-05) -- "Action of the Toes"
  • Flexdashboard 0.5.1.1
  • shiny 1.4.0

Example

--
title: "test"
output: flexdashboard::flex_dashboard
runtime: shiny
---

```{r}
library(flexdashboard)
library(shiny)
```

Inputs {.sidebar}
-------------------------------------

```{r}
selectInput(
  "month", 
  label = "Pick a Month",
  choices = month.abb, 
  selected = month.abb[2]
)

getmonth <- reactive({
  sprintf('Box 2 (%s)', input$month)
})

renderText({getmonth()})
```  

Column  
-------------------------------------

### `r renderText(getmonth())`

[cderv]

FWIW, I can reproduce with last version of rmarkdown, flexdashboard and shiny 1.4.0. It works with shiny 1.3.2. The issue seems to come from there.

[wch]

@schloerke and I bisected it to the commit in Shiny which upgrade to jQuery 3. This is probably a timing issue, related to:

• In some cases user-code may not have access to initShiny methods shiny#2630
• Statically rendered htmlwidgets in Shiny don't have access to Shiny methods registered in initShiny shiny#2635

[gorodnichy]

Unfortunately , I had the same problem.

I wanted to do this (input taken from shiny menu)

Country: r renderText(input$country)

It does not work - prints empty space

My sessionInfo below

R version 3.6.1 (2019-07-05)
Platform: x86_64-redhat-linux-gnu (64-bit)
Running under: Fedora 29 (Twenty Nine)

Matrix products: default
BLAS/LAPACK: /usr/lib64/R/lib/libRblas.so

locale:
[1] LC_CTYPE=en_CA.UTF-8 LC_NUMERIC=C LC_TIME=en_CA.UTF-8 LC_COLLATE=en_CA.UTF-8 LC_MONETARY=en_CA.UTF-8 LC_MESSAGES=en_CA.UTF-8
[7] LC_PAPER=en_CA.UTF-8 LC_NAME=C LC_ADDRESS=C LC_TELEPHONE=C LC_MEASUREMENT=en_CA.UTF-8 LC_IDENTIFICATION=C

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

other attached packages:
[1] dplyr_0.8.5 leaflet_2.0.3 DT_0.13 flexdashboard_0.5.1.1 stringr_1.4.0 lubridate_1.7.4 magrittr_1.5
[8] dtplyr_1.0.1 data.table_1.12.8 shiny_1.4.0.2 plotly_4.9.2 ggplot2_3.3.0