How to get a Shiny reactive action button to activate date inputs? - r

Question

I'm building a Shiny app where I need to take inputted dates and use them in a section of code that only runs on a button click.
For the life of me I cannot find an example on here or in documentation that I can get to work.
For the reprex example I simply want to print the inputted dates in the main panel once the 'Run Report' button is clicked.
I've iterated the server code for hours, but cannot get this to work.
UI:
fluidPage(titlePanel('File download'),
sidebarLayout(
sidebarPanel(
dateRangeInput(
inputId = "date.range",
label = "Select Date Range",
start = Sys.Date() - 2,
end = Sys.Date() - 1
),
actionButton(inputId = "runReport",
label = "Run Report")
),
mainPanel(verbatimTextOutput("date.text"))
))
... and server:
function(input, output, session) {
eventReactive(input$runReport, {
output$date.text <- renderPrint({
paste0(as.character(input$date.range[1]), "to", as.character(input$date.range[2]))
})
})
}

Answer 1

How about this:
ui <- fluidPage(titlePanel('File download'),
sidebarLayout(
sidebarPanel(
dateRangeInput(
inputId = "date.range",
label = "Select Date Range",
start = Sys.Date() - 2,
end = Sys.Date() - 1
),
actionButton(inputId = "runReport",
label = "Run Report")
),
mainPanel(verbatimTextOutput("date.text"))
))
server <- function(input, output, session) {
dates <- eventReactive(input$runReport, {
input$date.range
})
output$date.text <- renderPrint({
paste0(as.character(dates()[1]), " to ", as.character(dates()[2]))
})
}
shinyApp(ui, server)
In what's above, you use eventReactive() to update the dates() object only when the button is pushed. Then you do not need the reactive around the print statement because its inputs will automatically update when the button is pushed. This answer was instructive.