Demo pine

//@version=4
study("Demo Green or Red", shorttitle="Demo Green or Red", overlay=true)

green = close > open
red = close < open

plotshape(green , location=location.belowbar, style=shape.circle,
     color=color.green, textcolor=color.green, transp=0)
plotshape(red , location=location.abovebar, style=shape.circle,
     color=color.red, textcolor=color.red, transp=0)

alertcondition(green, "1: Long", message='Long')
alertcondition(red, "2: Short", message='Short')