shiny showing sidebar but not plot

Question

Quite new to shiny, can get the server to pop up - but only the drop down box will appear (no plot). Also, there a way to see each code concurrently on the same plot?

Current Script:

ui <- fluidPage(
  titlePanel("sample Title"),
  sidebarLayout(      

     sidebarPanel(
          selectInput("code", "Code:", 
          choices=colnames(stocks[2:ncol(stocks)])),
          hr(),
          helpText("Sample Heading") +
      ),
      mainPanel(
          plotOutput("samplePlot") + 
      )

  )
)

server <- function(input, output) {

  output$samplePlot <- renderPlot(

      ggplot(data = stocks, aes_string(x = 'date', y = input$code)) +
          geom_point() + geom_line() +
          xlab('Sample X') + ylab('Sample Y')
    )
}

shinyApp(ui, server)

SampleFile:

date    code    closeprice   volume    company
1/2/18  ABC     3.00         300       ABC Co
1/3/18  ABC     3.01         301       ABC Co
1/4/18  ABC     3.02         302       ABC Co
1/2/18  DEF     3.00         305       DEF Co
1/3/18  DEF     3.03         308       DEF Co
1/4/18  DEF     3.04         309       DEF Co

Answer 1

I think it's just the + signs in your ui that is messing things up. This should work:

ui <- fluidPage(
    titlePanel("sample Title"),
    sidebarLayout(      

        sidebarPanel(
            selectInput("code", "Code:", 
                        choices=colnames(stocks[2:ncol(stocks)])),
            hr(),
            helpText("Sample Heading") 
        ),
        mainPanel(
            plotOutput("samplePlot")  
        )

    )
)

server <- function(input, output) {

    output$samplePlot <- renderPlot(

        ggplot(data = stocks, aes_string(x = 'date', y = input$code)) +
            geom_point() + geom_line() +
            xlab('Sample X') + ylab('Sample Y')
    )
}

shinyApp(ui, server)