Shiny App dashboard initialises blank since update to v1.4

[SteveC]

Hi

Has anybody had any issues with an app having blank content initially and requiring a click on a reactive element to get going? There are no errors listed. When I 'run App' on a particular dashboard app with shiny package v1.4, it now loads a blank tab-content and requires clicking on one of the sidebar #shiny-tab elements to get the content to start showing. (The shinydashboard sidebar is all that shows). It doesn't matter which sidebar tab I code as the initially selected default. Even if it is a single fluidrow with a character vector for testing. Ultimately none of the main content area HTML elements load up until further user reactive input is given. This appears to be rather strange behavior since these package updates. Both the previous working package setup and problem one listed below:

This could be impacted by the packages; htmltools, DT possibly. (example App in next post).

[SteveC]

Here's a test app that doesn't initially load the table with the following R version and packages.

library(shiny)
library(DT)
library(shinydashboard)

ui <- tagList(
  tagList(
    dashboardPage(
      dashboardHeader(
        disable=F,
        title = "TEST",   titleWidth = 180 
      ),
      dashboardSidebar(collapsed = F, width = 180,sidebarMenuOutput("sideBar_menu_UI")),
      dashboardBody(
        uiOutput("page"))
    )
    
  )
)

server <- function(input, output) {
  output$sideBar_menu_UI <- renderMenu({
    sidebarMenu(id="tabs"
                ,menuItem("Primary", tabName = "primary_tab", icon = icon(""),selected = T )
                ,menuItem("test1", tabName = "test1_tab", icon = icon(""))
    )
  })
  
  
  output$test_dt <- DT::renderDataTable({
    DT::datatable(data.frame("col_1"=seq(1:2),"col_2"=seq(1:2)),
                  rownames = FALSE,colnames=c("col1","col2" ),
                  selection = 'none', class = 'cell-border stripe',
                  options = list(ordering=F, 
                                 columnDefs = list(list(className = 'dt-center',targets=c(0,1))),
                                 dom = 't'
                  )
    ) %>% formatStyle(0,target="row",lineHeight='12px')
  },server=T)
  
  output$page <- renderUI({
    tabItems( 
      tabItem(tabName = "primary_tab", mainPanel(width = 12,
                                                 fluidRow(box(width=12,DT::dataTableOutput('test_dt'),solidHeader = TRUE))
      )
      ),
      tabItem(tabName = "test1_tab", mainPanel(width = 12,
                                               HTML("<div style='height: 20px;'> </div>"),
                                               fluidRow("in dev")
      ))
    )
  })
  
}

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

Not working setup:

R version 3.4.4 (2018-03-15)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 16.04.6 LTS

Matrix products: default
BLAS: /usr/lib/libblas/libblas.so.3.6.0
LAPACK: /usr/lib/lapack/liblapack.so.3.6.0

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   
 [6] LC_MESSAGES=en_US.UTF-8    LC_PAPER=en_US.UTF-8       LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

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

other attached packages:
[1] shinydashboard_0.7.1 DT_0.9               shiny_1.4.0         

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.1        digest_0.6.15     later_1.0.0       mime_0.5          R6_2.2.2          jsonlite_1.5      xtable_1.8-2     
 [8] magrittr_1.5      rlang_0.4.0       promises_1.1.0    tools_3.4.4       htmlwidgets_1.5.1 crosstalk_1.0.0   httpuv_1.5.2     
[15] yaml_2.1.18       fastmap_1.0.1     compiler_3.4.4    htmltools_0.4.0     

Older setup / packages with no issue:

R version 3.4.4 (2018-03-15)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 16.04.6 LTS

Matrix products: default
BLAS: /usr/lib/libblas/libblas.so.3.6.0
LAPACK: /usr/lib/lapack/liblapack.so.3.6.0

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   
 [6] LC_MESSAGES=en_US.UTF-8    LC_PAPER=en_US.UTF-8       LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

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

other attached packages:
[1] shinydashboard_0.7.1 DT_0.7               shiny_1.3.2         

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.2      digest_0.6.22   later_1.0.0     mime_0.7        R6_2.4.0        xtable_1.8-4    jsonlite_1.6    magrittr_1.5    rlang_0.4.0    
[10] promises_1.1.0  tools_3.4.4     htmlwidgets_1.3 crosstalk_1.0.0 httpuv_1.5.2    yaml_2.2.0      compiler_3.4.4  htmltools_0.3.6