radioButtons() vs. uiOutput() and observeEvent(input[[""]] - shiny - shiny

Question

I try to observe an event in shiny. If I define a radio manually, it will be observed correctly - output: print(paste0("SELECT * FROM daten;")). I want to avoid writing several tenths of radio buttons in ui.r. Thus I wrote a loop in the server part.
But the same observeEvent() does not react on my "loop-listed" radio buttons which where correctly built in shiny app. I have no idea why.
I wrote a minimal example:
library(shiny)
shinyApp(
ui = fluidPage(
####### manually set radio #######
print("This radio 'pd1' will be observed:"),
radioButtons(inputId = "pd1", label = "value:", choices = c("?", "0", "1")),
br(), br(),
####### versus looped set set radio #######
uiOutput("scrlst"),
),
server = function(input, output) {
tablscr <- data.frame("1","question")
###################### observeEvent
##### "counter" for several items (in this case just 1 item)
rv <- reactiveValues(counter = 0)
lapply(1:dim(tablscr)[1], function(i) {
isolate({qnum <- paste0('pd', rv$counter <- rv$counter + 1)})
observeEvent(input[[qnum]], {print(paste0("SELECT * FROM daten;"))})
})
### output for tenths of items in one loop (in this case just 1 item)
output$scrlst <- renderUI({
tagList(
scr <- list(),
for (sq in 1:dim(tablscr)[1]){
scr[[sq]] = list(sq,
print("This radio 'pd1' will not be observed:"),
radioButtons(inputId = "pd1", label = "value:", choices = c("?", "0", "1")),
br(),
br()
)
},
return(scr),
)
})
}
)

Answer 1

Your tagList containing a loop and a return statement sounds weird. Moreover you have a duplicated id pd1. Here is a working code:
library(shiny)
shinyApp(
ui = fluidPage(
uiOutput("scrlst")
),
server = function(input, output) {
tablscr <- data.frame(c("1","2"), c("question", "hello"))
lapply(1:nrow(tablscr), function(i) {
qnum <- paste0('pd', i)
observeEvent(input[[qnum]], {print(paste0("SELECT * FROM daten;"))})
})
output$scrlst <- renderUI({
do.call(tagList, lapply(1:nrow(tablscr), function(i){
tagList(
radioButtons(paste0("pd", i), label = "value:", choices = c("?", "0", "1")),
br(), br()
)
}))
})
}
)