async support for Shiny

[alexturcan]

Hey,

It would be cool if this package were updated to support the recently added shiny async render functions. At the moment, renderCondformat() does not handle promises.

Here is a minimal repro:

library(shiny)
library(future)
library(promises)
library(condformat)
library(dplyr)

ui <- fluidPage(
  actionButton("execute", "Execute"),
  helpText("The synchronous table output"),
  condformatOutput("sync_table"),
  helpText("The asynchronous table output"),
  condformatOutput("async_table")
)

server <- function(input, output) {
  
  our_sync_data <- reactive({
    input$execute
    
    data.frame(type = c(rep("A", 5), rep("B", 5)),
               n = seq(1,100,10))
  })
  
  our_async_data <- reactive({
    input$execute
    
    future({
      
      data.frame(type = c(rep("A", 5), rep("B", 5)),
                 n = seq(1,100,10))
    })
  })
  
  output$sync_table <- renderCondformat({
    
    our_sync_data() %>% 
      condformat() %>% 
      rule_fill_discrete(type, expression = n <= 50,
                         colours = c("TRUE" = "yellowgreen", "FALSE" = "tomato"))
  })
  
  output$async_table <- renderCondformat({
    
    our_async_data() %...>% 
      condformat() %...>% 
      rule_fill_discrete(type, expression = n <= 50,
                         colours = c("TRUE" = "yellowgreen", "FALSE" = "tomato"))
  })
}

shinyApp(ui, server)

And here is the output of sessionInfo():

> sessionInfo()
R version 3.4.2 (2017-09-28)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS High Sierra 10.13.4

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

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

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

other attached packages:
[1] promises_1.0.1   dplyr_0.7.4      condformat_0.7.0 future_1.8.1     shiny_1.0.5 

Thank you!

[zeehio]

Thanks for the bug report and sorry for the late reply.

The issue is now solved in the dev version of condformat. Note that the solution depends on having htmlwidgets >= 1.3 installed, currently available on github.

devtools::install_github('ramnathv/htmlwidgets')

I will leave the issue open until htmlwidgets 1.3 is released, and once that happens I will close this issue and submit condformat to CRAN.

htmlwidgets current CRAN version:

Best

[zeehio]

Fix released on CRAN 0.8.0. (Windows and OSX packages will be built during the next ~48h)