alfreds_vix_app.R

library(shiny)
library(quantmod)

get_symbols <- function(symbol){
  symbol_data <- getSymbols(symbol,
                            src = "yahoo", 
                            auto.assign = FALSE)
  names(symbol_data) <- c("Open", "High", "Low", "Close", "Volume", "Adjusted.Close")
  symbol_data
}


plot_open_vs_close <- function(symbol_df, symbol){
  ggplot(symbol_df) + 
    geom_point(aes(x=Close, y=Open)) + 
    theme_classic() +
    ggtitle(symbol)
}

#ui
ui <- fluidPage(
  titlePanel("Alfreds VIX App"),
  sidebarLayout(
    sidebarPanel(
      textInput("symbol", "Symbol:", "VIX"),
      actionButton("search_button", "Go!")
    ),
    mainPanel(
      plotOutput("open_vs_close_plot"),
      tableOutput("summary")
    )
  )
)

#server

server <- function(input, output){
  symbol_data <- eventReactive(input$search_button, {
    get_symbols(input$symbol)
  })
  
  output$open_vs_close_plot <- renderPlot(
    plot_open_vs_close(symbol_data(), "symbol")
  )
  output$summary <- renderTable(head(symbol_data()))
  
}

shiny::shinyApp(ui = ui, server = server)