res/app.R

In AnneOkk/Feedback_reports_golem: Feedback Reports

# Only run this example in interactive R sessions
if (interactive()) {
    
    ## App 1: Sample usage
    shinyApp(
        ui = fluidPage(
            column(4,
                   numericInput("x", "Value", 5),
                   br(),
                   actionButton("button", "Show")
            ),
            column(8, tableOutput("table"))
        ),
        server = function(input, output) {
            # Take an action every time button is pressed;
            # here, we just print a message to the console
            observeEvent(input$button, {
                cat("Showing", input$x, "rows\n")
            })
            # Take a reactive dependency on input$button, but
            # not on any of the stuff inside the function
            df <- eventReactive(input$button, {
                head(cars, input$x)
            })
            output$table <- renderTable({
                df()
            })
        }
    )
    
    ## App 2: Using `once`
    shinyApp(
        ui = basicPage( actionButton("go", "Go")),
        server = function(input, output, session) {
            observeEvent(input$go, {
                print(paste("This will only be printed once; all",
                            "subsequent button clicks won't do anything"))
            }, once = TRUE)
        }
    )
    
    ## App 3: Using `ignoreInit` and `once`
    shinyApp(
        ui = basicPage(actionButton("go", "Go")),
        server = function(input, output, session) {
            observeEvent(input$go, {
                insertUI("#go", "afterEnd",
                         actionButton("dynamic", "click to remove"))
                
                # set up an observer that depends on the dynamic
                # input, so that it doesn't run when the input is
                # created, and only runs once after that (since
                # the side effect is remove the input from the DOM)
                observeEvent(input$dynamic, {
                    removeUI("#dynamic")
                }, ignoreInit = TRUE, once = TRUE)
            })
        }
    )
}