data-raw/app/app1.R

In ready4-dev/ready4use: Ingest, Label, Visualise and Share Health Economic Model Datasets

csvFileUI <- function(id, label = "CSV file") {
  # `NS(id)` returns a namespace function, which was save as `ns` and will
  # invoke later.
  ns <- NS(id)

  tagList(
    fileInput(ns("file"), label),
    checkboxInput(ns("heading"), "Has heading"),
    selectInput(ns("quote"), "Quote", c(
      "None" = "",
      "Double quote" = "\"",
      "Single quote" = "'"
    ))
  )
}
# Module server function
csvFileServer <- function(id, stringsAsFactors) {
  moduleServer(
    id,
    ## Below is the module function
    function(input, output, session) {
      # The selected file, if any
      userFile <- reactive({
        # If no file is selected, don't do anything
        validate(need(input$file, message = FALSE))
        input$file
      })

      # The user's data, parsed into a data frame
      dataframe <- reactive({
        read.csv(userFile()$datapath,
                 header = input$heading,
                 quote = input$quote,
                 stringsAsFactors = stringsAsFactors)
      })

      # We can run observers in here if we want to
      observe({
        msg <- sprintf("File %s was uploaded", userFile()$name)
        cat(msg, "\n")
      })

      # Return the reactive that yields the data frame
      return(dataframe)
    }
  )
}
library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      csvFileUI("datafile", "User data (.csv format)")
    ),
    mainPanel(
      dataTableOutput("table")
    )
  )
)

server <- function(input, output, session) {
  datafile <- csvFileServer("datafile", stringsAsFactors = FALSE)

  output$table <- renderDataTable({
    datafile()
  })
}

shinyApp(ui, server)