How to add the alertcondition() function in my script?

Question

I'm new on TradingView and currently testing pine script. I took one from ChartArt which is a double indicator strategy : RSI and Stochastic.

I was wondering how to add alerts but couldn't figured it out. Here the strategy :

//@version=2
strategy("Stochastic + RSI, Double Strategy (by ChartArt)", shorttitle="CA_-_RSI_Stoch_Strat", overlay=true)

// ChartArt's Stochastic Slow + Relative Strength Index, Double Strategy
//
// Version 1.0
// Idea by ChartArt on October 23, 2015.
//
// This strategy combines the classic RSI
// strategy to sell when the RSI increases
// over 70 (or to buy when it falls below 30),
// with the classic Stochastic Slow strategy
// to sell when the Stochastic oscillator
// exceeds the value of 80 (and to buy when
// this value is below 20).
//
// This simple strategy only triggers when
// both the RSI and the Stochastic are together
// in overbought or oversold conditions.
//
// List of my work: 
// https://www.tradingview.com/u/ChartArt/


///////////// Stochastic Slow
Stochlength = input(14, minval=1, title="lookback length of Stochastic")
StochOverBought = input(80, title="Stochastic overbought condition")
StochOverSold = input(20, title="Stochastic oversold condition")
smoothK = input(3, title="smoothing of Stochastic %K ")
smoothD = input(3, title="moving average of Stochastic %K")
k = sma(stoch(close, high, low, Stochlength), smoothK)
d = sma(k, smoothD)


///////////// RSI 
RSIlength = input( 14, minval=1 , title="lookback length of RSI")
RSIOverBought = input( 70  , title="RSI overbought condition")
RSIOverSold = input( 30  , title="RSI oversold condition")
RSIprice = close
vrsi = rsi(RSIprice, RSIlength)


///////////// Double strategy: RSI strategy + Stochastic strategy

if (not na(k) and not na(d))

    if (crossover(k,d) and k < StochOverSold)
        if (not na(vrsi)) and (crossover(vrsi, RSIOverSold))
            strategy.entry("LONG", strategy.long, comment="LONG")



if (crossunder(k,d) and k > StochOverBought)
    if (crossunder(vrsi, RSIOverBought))
        strategy.entry("SHORT", strategy.short, comment="SHORT")

To do so, we can use the function: alertcondition(). I tried to put it directly inside my conditions, but scope isn't correct. If i put it at the of the script and taking back the conditions of my if statements, then i don't receive data when testing the strategy. Also i couldn't get the custom alerts i wanted.

Another thing i tried is by creating two bool parameter which become true when in the good if statement. The condition inside alertcondition() become SHORT == true for instance. By doing so, i got the following error then : "Add to Chart operation failed, reason: The script must have at least one output function call (e.g. plot, barcolor, etc.). Reason: AST is Empty".

if (not na(k) and not na(d))

    if (crossover(k,d) and k < StochOverSold)
        if (not na(vrsi)) and (crossover(vrsi, RSIOverSold))
            strategy.entry("LONG", strategy.long, comment="LONG")
            SHORT = false
            LONG = true


if (crossunder(k,d) and k > StochOverBought)
    if (crossunder(vrsi, RSIOverBought))
        strategy.entry("SHORT", strategy.short, comment="SHORT")
        SHORT = true
        LONG  = false


alertcondition(SHORT == true, title='SHORT', message='SHORT message') 
alertcondition(LONG == true, title='LONG', message='LONG message')

Any idea on how to implement theses alerts ?

Baris Yakut Baris Yakut · Accepted Answer · 2019-09-13T17:25:44

Alerts cannot be created for strategy. So, you need to convert your strategy into an indicator.

Please note that, calling that function will not set-up alerts. You need to do that manually.

Here is the documentation of alertcondition. It tells you all you need to know with examples.

How to add the alertcondition() function in my script?

1 Answers