R shiny dashboard infobox with a dataset input

Question

I am new to r and shiny and suspect that I am stuck with a simple problem.

I want 2 infoboxes which show me in one the maximum amount over all categories and in the second infobox only the category with the most amount and its total amount.

I have tried a lot of things but nothing brought me success.

## app.R ##
library(shiny)
library(shinydashboard)

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(

    uiOutput("info_box1"),
    uiOutput("info_box2"),
    uiOutput("rawdata")
  )
)

set.seed(24)
mydf <- data.frame(Type = sample(LETTERS[1:5], 30, replace = TRUE),
                   Amount = sample(10:200, 30, replace = TRUE), 
                   stringsAsFactors= FALSE, check.names = FALSE)


server <- function(input, output) {

  output$info_box1 <- renderUI({
    infoBox("Amount in Total here", input$ "???")
  })

  output$info_box2 <- renderUI({
    infoBox("Class with the hightest amount and amount in total of that class", "input$ function needed?")
  })

  output$rawdata = renderTable({
    mydf
  })


}

# Run the application 
shinyApp(ui = ui, server = server)

Could someone please show me how to do this?

Thanks a lot. Appreciate your help.

Answer 1

You should use approriate functions, see here : https://rstudio.github.io/shinydashboard/structure.html

app.R

library(shiny)
library(shinydashboard)
library(dplyr)

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(

    infoBoxOutput("info_box1"),
    infoBoxOutput("info_box2"),
    tableOutput("rawdata")
  )
)

set.seed(24)
mydf <- data.frame(Type = sample(LETTERS[1:5], 30, replace = TRUE),
                   Amount = sample(10:200, 30, replace = TRUE), 
                   stringsAsFactors= FALSE, check.names = FALSE)


server <- function(input, output) {

  output$info_box1 <- renderInfoBox({
    infoBox("Amount in Total here", sum(mydf$Amount))
  })

  output$info_box2 <- renderInfoBox({
df_output <- mydf %>% group_by(Type) %>% tally()
    infoBox("Class with the hightest amount and amount in total of that class", paste(df_output$Type[df_output$n == max(df_output$n)],max(df_output$n))  )
  })

  output$rawdata = renderTable({
    mydf
  })


}

# Run the application 
shinyApp(ui = ui, server = server)