Using shiny's renderUI in Module - r

Question

this is my first question at stackoverflow. I have a problem with modules and renderUI in shiny (1.0.5).
When I use renderUI in
#### Main Part
ui <- bootstrapPage(
uiOutput("DynamicContent")
)
server <- function(input, output,session) {
S_A <- selectInput("S_A_Input" ,"Change Me for print message",choices=1:3 )
output$DynamicContent <- renderUI({
tagList(S_A)
})
observe({
print(input$S_A_Input)
})
}
shinyApp(ui = ui, server = server)
then changing the selectInput will cause changing input$S_A_Input, so the print will occur. That's fine.
On the other hand, input$S_A_Input seems not to work, if I work with modules:
### Module Part
Module_YYY_Server <- function(input, output, session){
S_A <- selectInput("S_A_Input" ,"Change Me for print message",choices=1:3 )
output$DynamicContent <- renderUI({
tagList(S_A)
})
observe({
print(input$S_A_Input)
})
}
Module_YYY_Ui <- function(id){
ns <- NS(id) # Creates Namespace
tagList(
uiOutput("DynamicContent" %>% ns)
)
}
And then calling the module.
#### Main Part
ui <- bootstrapPage(
Module_YYY_Ui("YYY")
)
server <- function(input, output,session) {
callModule(Module_YYY_Server,"YYY")
}
shinyApp(ui = ui, server = server)
I haven't found a solution to this behaviour.

Answer 1

Late to the party but this is another option to solve your problem using
session$ns("id")
Here how it looks like:
Module_YYY_Server <- function(input, output, session){
output$DynamicContent <- renderUI({
selectInput(session$ns("S_A_Input"), "Change Me for print message", choices = 1:3)
})
output$text <- renderText({
req(input$S_A_Input)
input$S_A_Input})
}
Module_YYY_Ui <- function(id){
ns <- NS(id) # Creates Namespace
tagList(
uiOutput(ns("DynamicContent")),
textOutput(ns("text"))
)
}
ui <- bootstrapPage(
Module_YYY_Ui("YYY")
)
server <- function(input, output,session) {
callModule(Module_YYY_Server,"YYY")
}
shinyApp(ui = ui, server = server)
This is based on the example here

Answer 2

While I am sure your example is simplified, If your input$S_A_Input is not changing based on what you are doing, as is the case in your example, I would not recommend using renderUI. Regardless of that, the reason that your input is not printing is because you are not generating it as an output.
Module_YYY_Server <- function(input, output, session){
output$DynamicContent <- renderUI({
ns <- session$ns
tagList(
selectInput("S_A_Input" %>% ns, "Change Me for print message",choices=1:3 )
)
})
output$text <- renderText({input$S_A_Input})
}
Module_YYY_Ui <- function(id){
ns <- NS(id) # Creates Namespace
tagList(
uiOutput("DynamicContent" %>% ns),
textOutput("text" %>% ns)
)
}