如何在指示器菜单中获取选项来启用或禁用指示器(一段代码，tradingview)？

//@version=4
study("Indicator Menu Example", overlay=true)

// 获取指示器菜单中的选项
indicatorMenu = input(title="Indicator", defval="SMA", options=["SMA", "EMA", "RSI", "MACD"])

// 根据选项来启用或禁用指示器
if indicatorMenu == "SMA"
    smaLength = input(title="SMA Length", defval=14)
    sma = sma(close, smaLength)
    plot(sma, color=color.blue, title="SMA")
else if indicatorMenu == "EMA"
    emaLength = input(title="EMA Length", defval=14)
    ema = ema(close, emaLength)
    plot(ema, color=color.red, title="EMA")
else if indicatorMenu == "RSI"
    rsiLength = input(title="RSI Length", defval=14)
    rsi = rsi(close, rsiLength)
    plot(rsi, color=color.green, title="RSI")
else if indicatorMenu == "MACD"
    [macdLine, signalLine, _] = macd(close)
    plot(macdLine - signalLine, color=color.orange, title="MACD")