app example

app.R

library(whereami)
library(ggplot2)

if(!file.exists('cars.csv')){
  readr::write_csv(mtcars,path = 'cars.csv') 
}

# Define the UI
ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      fileInput("file1", "Choose CSV File",
                accept = c(
                  "text/csv",
                  "text/comma-separated-values,text/plain",
                  ".csv")
      ),
      tags$hr(),
      shiny::uiOutput('xcol'),
      shiny::uiOutput('ycol')
    ),
    mainPanel(
      shiny::plotOutput('plot')
    )
  )
)

# Define the server code
server <- function(input, output) {
  
    dat <- eventReactive(input$file1,{
      inFile <- input$file1
      
      if (is.null(inFile))
        return(NULL)
      
      read.csv(inFile$datapath)
    })
  
    output$xcol <- renderUI({
      this_dat <- dat()
      
       shiny::selectizeInput(
        inputId = 'x',
        label = 'Select Column',
        choices = names(this_dat),
        selected = names(this_dat)[1]
        )
    })
    
    output$ycol <- renderUI({
      this_dat <- dat()
      
      shiny::selectizeInput(
        inputId = 'y',
        label = 'Select Column',
        choices = names(this_dat),
        selected = names(this_dat)[1]
      )
    })
    
      output$plot <- shiny::renderPlot({
        whereami::cat_where(whereami::whereami(tag = 'hist'))
        dat()%>%
          ggplot(aes(x = !!rlang::sym(input$x), y = !!rlang::sym(input$y))) + geom_point()
      })

}

# Return a Shiny app object
shinyApp(ui = ui, server = server)