How to count number of times the selectInput box is clicked? - r

Question

The below MWE code uses observeEvent() functions and reactiveVal() to track and show the number of times the selectInput() box is clicked and the number of times the actionButton() is clicked.
The actionButton() tracking works fine. Note how in output$... in the code the selectInput() and actionButton() work differently, looks weird to me.
Anyhow, I'm having trouble having selectInput() track the same as actionButton(). When the App is first invoked, the user clicking the first option rendered ("Cyl") in the selectInput() box is not counted as a click, when I would like it to count as a click. And if the same choice is clicked in the selectInput() ("Trans" for example) more than once, the clicks > 1 aren't counted as clicks when I would each click to be counted. Basically, anytime the user clicks in the selectInput() box it needs to be included as a "click". Is there any way to do this?
In the full code this matters because the selectInput() in that box triggers a removeUI() and the list of choices is dynamic and sequentially renumbered with every click.
Code:
library(shiny)
ui = fluidPage(hr(),
selectInput("selInput",label=NULL,c("Cyl"="cyl","Trans"="am","Gears"="gear"),selected=NULL),
actionButton("addBtn","Add"), hr(),
textOutput("clickSelInput"),
textOutput("clickAddBtn"),
tableOutput("data")
)
server = function(input, output) {
x = reactiveVal(0)
y = reactiveVal(0)
output$data <- renderTable({mtcars[1:10, c("mpg", input$selInput), drop = FALSE]})
observeEvent(input$selInput,{x(x()+1)})
observeEvent(input$addBtn,{y(y()+1)})
output$clickSelInput <- renderText({paste('Select Input clicks =',x()-1)})
output$clickAddBtn <- renderText({paste('Add Button clicks =',y())})
}
shinyApp(ui, server)

Answer 1

Adding "multiple = TRUE" to the selectInput() in this case resolves the question. Also allow the removal of the weird -1 from the out$selInput..x()-1)}) in the OP. This also works fine for the larger App this is intended for. See revised OP code with changes from OP commented (further down is the "larger App" where this functionality matters):
library(shiny)
ui = fluidPage(hr(),
selectInput("selInput",
label=NULL,
c("Cyl"="cyl","Trans"="am","Gears"="gear"),
selected=NULL,
multiple=TRUE # added this
),
actionButton("addBtn","Add"), hr(),
textOutput("clickSelInput"),
textOutput("clickAddBtn"),
tableOutput("data")
)
server = function(input, output) {
x = reactiveVal(0)
y = reactiveVal(0)
output$data <- renderTable({mtcars[1:10, c("mpg", input$selInput), drop = FALSE]})
observeEvent(input$selInput,{x(x()+1)})
observeEvent(input$addBtn,{y(y()+1)})
output$clickSelInput <- renderText({paste('Select Input clicks =',x())}) # removed the -1 from x()
output$clickAddBtn <- renderText({paste('Add Button clicks =',y())})
}
shinyApp(ui, server)
And here's the "larger App" where this functionality matters:
library(dplyr)
library(rhandsontable)
library(shiny)
rowNames1 <- c("A", "B", "C", "Sum")
DF1 <- data.frame(row.names = rowNames1, "Col 1" = c(1, 1, 0, 2), check.names = FALSE)
ui <- fluidPage(br(),
rHandsontableOutput('hottable1'),br(),
actionButton("addCol1", "Add column 1"),br(),
h5(strong("Select column to delete:")),
uiOutput("delCol1"), hr(),
textOutput("clickSelInput"),
textOutput("clickAddBtn"),
)
server <- function(input, output) {
x = reactiveVal(0)
y = reactiveVal(0)
uiTbl1 <- reactiveVal(DF1)
observeEvent(input$hottable1, {uiTbl1(hot_to_r(input$hottable1))})
output$hottable1 <- renderRHandsontable({
rhandsontable(uiTbl1(),rowHeaderWidth = 100, useTypes = TRUE)%>%
hot_context_menu(allowRowEdit = FALSE, allowColEdit = FALSE)
})
observeEvent(input$addCol1, {
newCol <- data.frame(c(1,1,0,2))
names(newCol) <- paste("Col", ncol(hot_to_r(input$hottable1)) + 1)
uiTbl1(cbind(uiTbl1(), newCol))
})
observeEvent(input$delCol1, {
tmp <- uiTbl1()
delCol <- input$delCol1
tmp <- tmp[ , !(names(tmp) %in% delCol), drop = FALSE]
newNames <- sprintf("Col %d",seq(1:ncol(tmp)))
names(tmp) <- newNames
uiTbl1(tmp)
})
output$delCol1 <-
renderUI(
selectInput(
"delCol1",
label = NULL,
choices = colnames(hot_to_r(input$hottable1)),
selected = "",
multiple = TRUE)
)
observeEvent(input$delCol1,{x(x()+1)})
observeEvent(input$addCol1,{y(y()+1)})
output$clickSelInput <- renderText({paste('Select Input clicks =',x())})
output$clickAddBtn <- renderText({paste('Add Button clicks =',y())})
}
shinyApp(ui,server)