Shiny Gadget to load SQL Queries (ugly and not totally working)

sqlWizardGadget

library(shiny)
library(miniUI)

ui <- miniPage(
  gadgetTitleBar("Import SQL Query"),
  miniTabstripPanel(
    selected = "Input",
    # --- UI - Tab - Input ----
    miniTabPanel(
      "Input",
      # icon = icon("file-text-o"),
      miniContentPanel(
        fillCol(
          fileInput("file", "Choose SQL File", accept = ".sql")
        )
      )
    ),
    # --- UI - Tab - Query ----
    miniTabPanel(
      "Query",
      miniContentPanel(
        verbatimTextOutput("queryText")
      )
    ),
    # --- UI - Tab - Preview ----
    miniTabPanel(
      "Preview",
      miniContentPanel(
        fillCol(
          miniContentPanel(
            tableOutput("previewTable")
          )
        )
      )
    ),
    # --- UI - Tab - Output ----
    miniTabPanel(
      "Output",
      miniContentPanel(
        fillCol(
          textInput("outVar", "Variable Name"),
          br(),
          actionButton("sendToGlobalEnv", "Send to Environment")
        )
      )
    )
  )
)

server <- function(input, output, session) {

  input_file <- reactive({
    if (is.null(input$file)) {
      return("")
    }
  readr::read_lines(input$file$datapath)
  })

  output$queryText <- renderText({
    req(input_file())
    lines <- input_file()
    paste(lines[2:length(lines)], collapse = "\n")
  })

  output$previewTable <- renderTable({
    req(input_file())
    lines <- input_file()
    connection_string <- stringr::str_extract(lines[1], "(?<=\\=).*")
    connection_call <- paste0("con <- ", connection_string)
    eval(parse(text = connection_call))
    on.exit(DBI::dbDisconnect(con))
    query <- paste(lines[2:length(lines)], collapse = " ")
    out <- DBI::dbGetQuery(con, query)
    table_out <- reactiveVal(out)
    out
  })

  observeEvent(input$sendToGlobalEnv, {
    assign(input$outVar, table_out, envir = globalenv())
  })

  observeEvent(input$done, {
    stopApp(TRUE)
  })

}

runGadget(ui, server, viewer = paneViewer())