Error while uploading a file using file input - r

Question

I am trying to develop an application, that could help the users upload a file and display the summary statistics.
I am using the below UI and Server code to achieve this, once I have completed my file upload, i am unable to see the data frame and its summary statistics.
I am missing something with my code, but unable to guess.
ui<-dashboardPage(
dashboardHeader(title = "Claim Model"),
dashboardSidebar(
sidebarMenu(id="tabs",
menuItem("Data", tabName = "data", icon = icon("table"),startExpanded = TRUE,
menuSubItem("Load", tabName = "data1")
),
menuItem("Visualisation",icon=icon("bar-chart-o"), tabName = "vis"),
menuItem("Result", icon=icon("cog"), tabName = "result")
)
),
dashboardBody(
tags$style(type="text/css",
".shiny-output-error { visibility: hidden; }",
".shiny-output-error:before { visibility: hidden; }"
),
tabItems(
tabItem(tabName = "data1",
fluidPage(
fluidRow(
fileInput("file1","Choose CSV File",
accept = c("text/csv",
"text/comma-seperated-values, text/plain",
".csv")
),
tags$hr(),
checkboxInput("header", "Header", TRUE),
radioButtons("sep","Separator",
choices=c(Comma=",",
semicolon=";",
Tab="\t"),
selected = ";")
),
mainPanel(
tableOutput("contents")
)
)
)
)
)
)
Server Code.
server <- shinyServer(function(input,output){
output$contents <- renderTable({
req(input$file1)
df <- read.csv(input$file1$datapath,
header=input$header,
sep=input$sep)
})
})
Currently i dont have the code for displaying the statistics from data frame. any lead on how to start would be helpful

Answer 1

Here is an example: Inside dashboardBody(), you need a second (and third) tabItem() to "fill" the menuItem(tabName = "vis") and menuItem(tabName = "result"). And in the server, you need code to generate plots or tables or whatever you want to display. Furthermore, note how I assigned the output of read.csv() to a function (called DATA() here) so that it can be used at different places inside the server.
UI:
ui <- dashboardPage(
dashboardHeader(title = "Claim Model"),
dashboardSidebar(
sidebarMenu(id="tabs",
menuItem("Data", tabName = "data", icon = icon("table"),startExpanded = TRUE,
menuSubItem("Load", tabName = "data1")
),
menuItem("Visualisation",icon=icon("bar-chart-o"), tabName = "vis"),
menuItem("Result", icon=icon("cog"), tabName = "result")
)
),
dashboardBody(
tags$style(type="text/css",
".shiny-output-error { visibility: hidden; }",
".shiny-output-error:before { visibility: hidden; }"
),
tabItems(
tabItem(tabName = "data1",
fluidPage(
fluidRow(
fileInput("file1","Choose CSV File",
accept = c("text/csv",
"text/comma-seperated-values, text/plain",
".csv")
),
tags$hr(),
checkboxInput("header", "Header", TRUE),
radioButtons("sep","Separator",
choices=c(Comma=",",
semicolon=";",
Tab="\t"),
selected = ";")
),
mainPanel(
tableOutput("contents")
)
)
),
tabItem(tabName = "vis", h2("Two Plots"),
fluidRow(
box(
title = "Plot 1", solidHeader = TRUE, collapsible = TRUE,
plotOutput("hist1")
),
box(
title = "Plot 2", solidHeader = TRUE, collapsible = TRUE,
plotOutput("hist2")
)
)
)
)
)
)
server:
server <- function(input, output) {
DATA <- reactive({
req(input$file1)
df <- read.csv(input$file1$datapath,
header = input$header,
sep = input$sep)
return(df)
})
output$contents <- renderTable(DATA())
output$hist1 <- renderPlot({
tmp1 <- sample(which(apply(DATA(), 2, is.numeric)), 1)
hist(DATA()[, tmp1], breaks = 10, xlab = names(DATA())[tmp1], main = "")
})
output$hist2 <- renderPlot({
tmp1 <- sample(which(apply(DATA(), 2, is.numeric)), 1)
hist(DATA()[, tmp1], breaks = 20, xlab = names(DATA())[tmp1], main = "")
})
}
run:
library(shiny)
library(shinydashboard)
shinyApp(ui, server)