app.R

# import Shiny library
library(shiny)
# define UI component
ui <- fluidPage(
    titlePanel("Dice Roller App"),
    sidebarLayout(
        sidebarPanel(
            numericInput(
                "dice",
                "Number of Dice",
                value = 1,
                min = 1,
                step = 1
            ), # number of dice input
            numericInput(
                "sides",
                "Number of Sides",
                value = 6,
                min = 1,
                step = 1
            ), # number of sides input
            checkboxInput("rollList", "Show List of Dice Rolls", value = FALSE), # checkbox to show list of dice rolls
            checkboxInput("plot", "Plot Dice Rolls"), # checkbox to plot list of dice rolls
            actionButton("roll", "Roll Dice") # button to roll dice
        ),
        mainPanel(
            textOutput("diceRollSum"), # dice roll sum text output
            textOutput("diceRollValues"), # dice roll values text output
            textOutput("sortedDiceRollValues"), # sorted dice roll values text output
            textOutput("diceRollList"), # dice roll list text output
            plotOutput("diceRollPlot") # dice roll plot output
        )
    )
)
server <- function(input, output) {
    # when roll dice button is pressed
    observeEvent(input$roll, {
        # roll dice
        diceRolls <- sample(1:input$sides, input$dice, replace = TRUE)
        # table of dice rolls
        diceRollsTable <- table(diceRolls)
        # convert table to data frame
        sortedDiceRollsTable <- as.data.frame(diceRollsTable)
        # sort dice rolls
        sortedDiceRolls <- sortedDiceRollsTable[
            order(sortedDiceRollsTable$Freq, decreasing = TRUE),
        ]
        # set output to sum of dice rolls
        output$diceRollSum <- renderText(paste("Total Dice: ", sum(diceRolls)))
        # set output to values of dice rolls
        output$diceRollValues <- renderText(paste(
            "Dice Rolls by Number: \n",
            paste(
                names(diceRollsTable),
                diceRollsTable,
                sep = ": ",
                collapse = "\n"
            )
        ))
        # set output to sorted values of dice rolls
        output$sortedDiceRollValues <- renderText(paste(
            "Sorted Dice Rolls by Number: \n",
            paste(
                sortedDiceRolls$diceRolls,
                sortedDiceRolls$Freq,
                sep = ": ",
                collapse = "\n"
            )
        ))
        # show list of dice rolls if checkbox is checked
        if (input$rollList) {
            output$diceRollList <- renderText(paste(
                "List of Dice Rolls: \n",
                paste(diceRolls, collapse = ", ")
            ))
        } else {
            output$diceRollList <- renderText("")
        }
        # show plot of dice rolls if checkbox is checked
        if (input$plot) {
            output$diceRollPlot <- renderPlot({
                barplot(
                    diceRollsTable,
                    main = "Dice Rolls",
                    xlab = "Dice",
                    ylab = "Frequency",
                    col = "blue"
                ) # plot list of dice rolls
            })
        } else {
            output$diceRollPlot <- renderPlot({
                plot.new() # render empty and blank plot
            })
        }
    })
}

shinyApp(ui = ui, server = server) # run the Shiny web app server