R Shiny: Dynamic Row of Action Buttons - r

Question

I want to have a set of two action buttons in Shiny where the inputID and number of duplicates is based off the number of rows in a data.frame. Attached below is my thought process that isn't currently functioning correct. Instead of adding a button whenever a button is pressed, I want "n" sets of buttons equal to the number of rows in a data.frame.
library(shiny)
ui <- basicPage(
fluidRow(
actionButton(inputId = "add_button",
label = "Add Button")
),
uiOutput("more_buttons")
)
server <- function(input, output){
rvs <- reactiveValues(buttons = list(actionButton(inputId = "button1",
label = 1)))
observeEvent(eventExpr = input$add_button,
handlerExpr = {
len <- length(rvs$buttons) + 1
rvs$buttons[[len]] <- actionButton(inputId = paste0("button",len),
label = len)
})
output$more_buttons <- renderUI({
do.call(fluidRow, rvs$buttons)
})
observeEvent(rvs$buttons,{
for(ii in 1:length(rvs$buttons)){
local({
i <- ii
observeEvent(eventExpr = input[[paste0("button",i)]],
handlerExpr = {print(sprintf("You clicked btn number %d",i))})
})
}
})
}
shinyApp(ui, server)

Answer 1

Here is a simplified version of what you want to accomplish
ui <- fluidPage(
selectInput("df", "choose a dataframe",
c("mtcars", "mpg")),
uiOutput("buttons")
)
server = function(input, output, session){
reactiveFrame = reactive({
if(input$df == "mtcars")
return(mtcars)
return(ggplot2::mpg)
})
nrowR = reactive({
nrow(reactiveFrame())
})
m <- 0
output$buttons = renderUI({
m <- m+1
do.call(
fluidPage,
lapply(
1:nrowR(),
function(i)
span(
actionButton(paste0("a", i, "-", m),paste0("a", i)),
actionButton(paste0("b", i, "-", m),paste0("b", i))
)
)
)
})
}
shinyApp(ui,server)