Shiny: Plotting from user uploaded data

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1

Dear colleagues,

I am working on a shiny app in which I am attempting to accept a CSV upload from the user and then create a ggplot from the uploaded file.

Here is a reprex of my UI logic:

tabPanel("Upload", 
        sidebarLayout(
            sidebarPanel(
                fileInput("file1", "Choose CSV File",
                          accept = c(
                              "text/csv",
                              "text/comma-separated-values,text/plain",
                              ".csv")
                ),
                tags$hr(),
                checkboxInput("header", "Header", TRUE)
            ),
            mainPanel(
                tableOutput("contents"),plotOutput("upload"),
            )
        )
        
    )
#> Error in tabPanel("Upload", sidebarLayout(sidebarPanel(fileInput("file1", : could not find function "tabPanel"

Server logic:

 output$contents <- renderTable({
        
        inFile <- input$filedata
        
        if (is.null(inFile))
            return(NULL)
        
    })
#> Error in renderTable({: could not find function "renderTable"
#> Error in renderTable({: could not find function "renderTable"
    
    output$upload <- renderPlot({
        inFile <- input$file1
        
        if (is.null(inFile))
            return(NULL)
        
        uploadr<-read.csv(inFile$datapath, header = input$header)
        uploadr %>%
            ggplot(aes(x=Product, y=Stock))+geom_col()
    })
#> Error in renderPlot({: could not find function "renderPlot"
#> Error in renderPlot({: could not find function "renderPlot"

Any ideas on what's going wrong here? My app is currently returning the error message: duplicate 'row.names' are not allowed.

Thank you for your help in advance. I've been stuck on this for quite some time, so any insight would be greatly appreciated.

2

Is you error occurring in your table output or your plot output? The code in your renderTable section is not actually displaying the table but just displaying a (nonexistent?) input. You should probably read your users filepath in a reactive and then pass that to the plot and table:

function(input, output, session){
  user_data <- reactive({
    if (is.null(input$file1)) return(NULL)
    read.csv(input$file1$datapath, header = input$header)
  })

  output$contents <- renderTable({
    req(user_data()) # if user_data() is null than the reactive will not run

    user_data()
  })

  output$upload <- renderPlot({
    req(user_data())

    if (all(c("Product", "Stock") %in% colnames(user_data()))) return(NULL) # make sure your target columns in dataset uploaded
    ggplot(user_data(), aes(x = Product, y = Stock)) + 
      geom_col()
  })
}
3

Hello,

Thank you for your help. I tried this and it seemed to now produce " duplicate 'row.names' are not allowed" 2 times instead of once. Any idea on what this error message means?

4

it looks like you have to add row.names = NULL to the read.csv function according to this SO post

5

Awesome. This works in displaying the table, but the plot doesn't yet appear. Does the object need to be printed inside of the renderPlot in order to make it work?