Ticker labels after plot - label

Question

I would really appreciate some help adding a ticker label after my plot from the code below. Below is an extract of the main code - I've only used the lines for 1 ticker but in reality, I'll have 32 symbols in total so I've omitted the unnecessary code duplication for the other tickers for the purposes of this query.
Any improvements on the rest of the code would also be appreciated. I'm using ticker.new as 1) I don't need the inputs and the plot only seemed to display properly when the session was listed as extended (even though the chart was already set to extended)
//#version=5
indicator('NASDAQ Trend', overlay=true)
// SYMBOLS //
s01 = ticker.new("NASDAQ", "AAL", session.extended)
// CALCULATIONS //
screener_func() =>
//STACKED EMAs
MA1 = ta.ema(close, 5)
MA2 = ta.ema(close, 8)
MA3 = ta.ema(close, 13)
MA4 = ta.ema(close, 21)
MA5 = ta.ema(close, 34)
MA_Stack_Up = (MA1 > MA2) and (MA2 > MA3) and (MA3 > MA4) and (MA4 > MA5)
//CONDITIONS
Uptrend = MA_Stack_Up
Reversal = ((MA1 < MA2) and (MA2 > MA3)) or ((MA1 > MA2) and (MA2 < MA3))
//COLOR CODING
Bar_Color = Uptrend ? color.new(color.green, 25) : Reversal ? color.new(color.yellow, 25) : color.new(color.red, 25)
[Bar_Color]
// Security call
[TS01]= request.security(s01, timeframe.period, screener_func())
// PLOTS //
l_width = 3
shape = plot.style_circles
plot(1, color=TS01, style=shape, linewidth=l_width)
//LABELS//
L1= label.new(bar_index, 1, text=s01, style=label.style_none, textcolor=color.new(color.white, 0), size=size.small)
label.delete(L1[1])
My problem is the resulting label is ={"session":"extended","symbol":"NASDAQ:AAL"}. Ideally, the label should be just AAL

Answer 1

You can write a function that extracts the part you are interested from that string. If your string ALWAYS has the same format ={"session":"extended","symbol":"NASDAQ:AAL"}.
Step 1: Split the string using : as a delimeter. You will then have 4 sub strings.
={"session"
"extended","symbol"
"NASDAQ
AAL"} <-- This is what you want (index: 3)
Step 2: Remove the last two chars. Since the last two chars will always be "}, return a string until last two chars.
getName(_str) =>
string[] _pair = str.split(_str, ":")
string[] _chars = str.split(array.get(_pair, 3), "") // Index 3
int _len = array.size(_chars) - 2 // Don't get the last two chars
string[] _substr = array.new_string(0)
_substr := array.slice(_chars, 0, _len)
string _return = array.join(_substr, "")
Then call this function when you create a label:
//LABELS//
L1= label.new(bar_index, 1, text=getName(s01), style=label.style_none, textcolor=color.new(color.white, 0), size=size.small)
label.delete(L1[1])

Answer 2

No sense in doing all those string gymnastics when the ticker is available. Try this:
//#version=5
indicator('NASDAQ Trend', overlay=true)
// CALCULATIONS // {
// hey look – it's now foldable....
screener_func() =>
// STACKED EMAs
MA1 = ta.ema(close, 5)
MA2 = ta.ema(close, 8)
MA3 = ta.ema(close, 13)
MA4 = ta.ema(close, 21)
MA5 = ta.ema(close, 34)
// CONDITIONS - no sense in allocating extra variables when hidden in function
Uptrend = (MA1 > MA2) and (MA2 > MA3) and (MA3 > MA4) and (MA4 > MA5)
Reversal = ((MA1 < MA2) and (MA2 > MA3)) or ((MA1 > MA2) and (MA2 < MA3))
// DETERMINE COLOR CODING - just return the results
// vs assigning to a variable and then return the variable...
[Uptrend ? color.new(color.green, 25) : Reversal ? color.new(color.yellow, 25) : color.new(color.red, 25)]
// }
// Define tickers and set up labels on last bar
// Note: request security limits the max number of tickers to 40
var tickers = array.from("AA","AAL","AAPL")
// use the index of the symbol in the ticker array as price level to plot...
if barstate.islast
for item in tickers
label.new(bar_index+ 5, array.indexof(tickers,item), item, style=label.style_none, textcolor=color.new(color.white, 0), size=size.small)
// Since the ticker symbol must be know at complile time aka simple string,
// we have to call each symbol separately - what a pain...
// style variations here in case we want to change
var aStyle = plot.style_circles
var aLinewidth = 3
// AA <-- Yep this is definitely not NASDAQ material...
temp1 = ticker.new("NYSE", "AA", session.extended)
[temp2] = request.security(temp1, timeframe.period, screener_func())
plot(0, color= temp2, style=aStyle, linewidth=aLinewidth)
// AAL
temp3 = ticker.new("NASDAQ", "AAL", session.extended)
[temp4] = request.security(temp3, timeframe.period, screener_func())
plot(1, color= temp4, style=aStyle, linewidth=aLinewidth)
// AAPL
temp5 = ticker.new("NASDAQ", "AAPL", session.extended)
[temp6] = request.security(temp5, timeframe.period, screener_func())
plot(2, color= temp6, style=aStyle, linewidth=aLinewidth)
output image