Mastering Pine Script: A Guide to Its Structure and Flow

byPro Trading Art -
0

 



1. Overview of Pine Script Structure

A Pine Script follows a general structure, which includes the following components:

  • Version: Specifies the script version.
  • Declaration Statement: Defines the type of script and its properties.
  • Code: Implements the algorithm using statements.
// This source code is subject to the terms of the Mozilla Public License 2.0 at <https://mozilla.org/MPL/2.0/>
// © protradingart

//@version=5
indicator("Pro Trading Art - Double Top & Bottom with alert", "PTA - Double Top & Bottom", overlay=true, max_lines_count=500, max_labels_count=500)

//////////////////////////////////////////////////////
////////////////////////////////////////////////////////
method maintainPivot(array<float> srcArray, float value) =>
    srcArray.push(value)
    srcArray.shift()

method maintainIndex(array<int> srcArray, int value) =>
    srcArray.push(value)
    srcArray.shift()

method middleIndex(array<int> srcArray)=>
    srcArray.get(srcArray.size()-2)

method middlePrice(array<float> srcArray)=>
    srcArray.get(srcArray.size()-2)

drawLL(start, end, price, startText, endText, COLOR, style=label.style_label_down)=>
    Line = line.new(x1=start, y1=price, x2=end, y2=price, color=COLOR, width=2)
    A = label.new(x=start, y=price, text=startText, color=COLOR, style=style, textcolor=color.black, size=size.normal)
    B = label.new(x=end, y=price, text=endText, color=COLOR, style=style, textcolor=color.black, size=size.normal)
    [Line, A, B]
////////////////////////////////////////////////////////
////////////////////////////////////////////////////////
pivotLeg = input.int(10, "Pivot Length")
extendSignal = input.bool(false, "Extend Signal")

var top = array.new_float(3)
var bottom = array.new_float(3)

var topIndex = array.new_int(3)
var bottomIndex = array.new_int(3)

ph = ta.pivothigh(pivotLeg, pivotLeg)
pl = ta.pivotlow(pivotLeg, pivotLeg)

////////////// Top ///////////////////
if not na(ph)
    top.maintainPivot(ph)
    topIndex.maintainIndex(bar_index-pivotLeg)

////////////// Bottom ///////////////////
if not na(pl)
    bottom.maintainPivot(pl)
    bottomIndex.maintainIndex(bar_index-pivotLeg)

inRange = not na(top.first()) and (not na(bottom.first()))
////////////////////////// Top Calculation //////////////////////////////////////////////////////    
topPrice = 0.0
isTop = false
var line topLine = na
var label topA = na
var label topB = na

if inRange
    topStart = topIndex.last()
    topPrice := top.last()
    
    if topPrice < top.middlePrice() and topIndex.middleIndex() > bottomIndex.first()
        topPrice := top.middlePrice()
        topStart := topIndex.middleIndex()

    max_index = top.indexof(top.max())
    if topPrice < top.max() and topIndex.get(max_index) > bottomIndex.first()
        topPrice := top.max()
        topStart := topIndex.get(max_index)
    
    isTop := high >= topPrice and high[1] < topPrice and low < topPrice and bottom.last() > bottom.middlePrice()

    var lastStart = 0
    var topEnd = 0
    if isTop and topStart != lastStart
        lastStart := topStart
        [Line, A, B] = drawLL(topStart, bar_index, topPrice, "Top 1", "Top 2", color.lime)
        topLine := Line
        topA := A
        topB := B
        alert("Double Top In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossunder(close, topLine.get_y2()) and extendSignal
    topLine.set_x2(bar_index)
    label.new(bar_index, high, style = label.style_label_down, color=color.red)
    alert("Double Top Breakdown In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossover(close, topLine.get_y2()) and extendSignal
    topLine.set_x2(bar_index)
    label.new(bar_index, low, style = label.style_label_up, color=color.green)
    alert("Double Top Breakout In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

// ////////////////////////// Bottom Calculation //////////////////////////////////////////////////////    
bottomPrice = 0.0
isBottom = false
var line bottomLine = na
var label bottomA = na
var label bottomB = na

if inRange
    bottomStart = bottomIndex.last()
    bottomPrice := bottom.last()
    
    if bottomPrice > bottom.middlePrice() and bottomIndex.middleIndex() > topIndex.first()
        bottomPrice := bottom.middlePrice()
        bottomStart := bottomIndex.middleIndex()
    
    min_index = bottom.indexof(bottom.min())
    if bottomPrice > bottom.min() and bottomIndex.get(min_index) > topIndex.first()
        bottomPrice := bottom.min()
        bottomStart := bottomIndex.get(min_index)
        
    isBottom := close <= bottomPrice and close[1] > bottomPrice and high > bottomPrice and top.last() < top.middlePrice()

    var bottomEnd = 0
    var lastStart = 0

    if isBottom and  bottomStart != lastStart
        lastStart := bottomStart
        [Line, A, B] = drawLL(bottomStart, bar_index, bottomPrice, "Bottom 1", "Bottom 2", color.red, label.style_label_up)
        bottomLine := Line
        bottomA := A
        bottomB := B
        alert("Double Bottom In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossunder(close, bottomLine.get_y2()) and extendSignal
    bottomLine.set_x2(bar_index)
    label.new(bar_index, high, style = label.style_label_down, color=color.red)
    alert("Double Bottom Breakdown In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossover(close, bottomLine.get_y2()) and extendSignal
    bottomLine.set_x2(bar_index)
    label.new(bar_index, low, style = label.style_label_up, color=color.green)
    alert("Double Bottom Breakout In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

2. Version

  • The version of Pine Script is specified using the //@version= compiler annotation.

  • Example:

    //@version=6

  • The version number ranges from 1 to 6.

  • If omitted, version 1 is assumed. It is recommended to always use the latest version.

3. Declaration Statement

Every Pine Script must include one declaration statement. The statement determines:

  1. Script Type:

    • Indicator: Requires at least one visual output function (e.g., plot()).
    • Strategy: Requires at least one strategy.*() function call.
    • Library: Must include exported functions or user-defined types.

  2. Properties:

    • Title, runtime behavior, and backtesting parameters.
    • Examples:

    <aside> <img src="/icons/bell-notification_green.svg" alt="/icons/bell-notification_green.svg" width="40px" />

    For an indicator:

    indicator("My Indicator"))

    </aside>

    <aside> <img src="/icons/bell-notification_green.svg" alt="/icons/bell-notification_green.svg" width="40px" />

    For a strategy:

    strategy("My Strategy", overlay=true)

    </aside>

4. Code

The algorithm implementation in Pine Script consists of statements. These include:

  • Variable declaration/reassignment.

  • Function declarations.

  • Built-in, user-defined, or library function calls.

  • Control structures: if, for, while, switch, etc.

  • Scope and Indentation:

    • Global scope statements must begin without indentation.
    • Local blocks require an indentation (4 spaces or 1 tab).

  • Example:

    // This source code is subject to the terms of the Mozilla Public License 2.0 at <https://mozilla.org/MPL/2.0/>
// © protradingart

//@version=5
indicator("Pro Trading Art - Double Top & Bottom with alert", "PTA - Double Top & Bottom", overlay=true, max_lines_count=500, max_labels_count=500)

//////////////////////////////////////////////////////
////////////////////////////////////////////////////////
method maintainPivot(array<float> srcArray, float value) =>
    srcArray.push(value)
    srcArray.shift()

method maintainIndex(array<int> srcArray, int value) =>
    srcArray.push(value)
    srcArray.shift()

method middleIndex(array<int> srcArray)=>
    srcArray.get(srcArray.size()-2)

method middlePrice(array<float> srcArray)=>
    srcArray.get(srcArray.size()-2)

drawLL(start, end, price, startText, endText, COLOR, style=label.style_label_down)=>
    Line = line.new(x1=start, y1=price, x2=end, y2=price, color=COLOR, width=2)
    A = label.new(x=start, y=price, text=startText, color=COLOR, style=style, textcolor=color.black, size=size.normal)
    B = label.new(x=end, y=price, text=endText, color=COLOR, style=style, textcolor=color.black, size=size.normal)
    [Line, A, B]
////////////////////////////////////////////////////////
////////////////////////////////////////////////////////
pivotLeg = input.int(10, "Pivot Length")
extendSignal = input.bool(false, "Extend Signal")

var top = array.new_float(3)
var bottom = array.new_float(3)

var topIndex = array.new_int(3)
var bottomIndex = array.new_int(3)

ph = ta.pivothigh(pivotLeg, pivotLeg)
pl = ta.pivotlow(pivotLeg, pivotLeg)

////////////// Top ///////////////////
if not na(ph)
    top.maintainPivot(ph)
    topIndex.maintainIndex(bar_index-pivotLeg)

////////////// Bottom ///////////////////
if not na(pl)
    bottom.maintainPivot(pl)
    bottomIndex.maintainIndex(bar_index-pivotLeg)

inRange = not na(top.first()) and (not na(bottom.first()))
////////////////////////// Top Calculation //////////////////////////////////////////////////////    
topPrice = 0.0
isTop = false
var line topLine = na
var label topA = na
var label topB = na

if inRange
    topStart = topIndex.last()
    topPrice := top.last()
    
    if topPrice < top.middlePrice() and topIndex.middleIndex() > bottomIndex.first()
        topPrice := top.middlePrice()
        topStart := topIndex.middleIndex()

    max_index = top.indexof(top.max())
    if topPrice < top.max() and topIndex.get(max_index) > bottomIndex.first()
        topPrice := top.max()
        topStart := topIndex.get(max_index)
    
    isTop := high >= topPrice and high[1] < topPrice and low < topPrice and bottom.last() > bottom.middlePrice()

    var lastStart = 0
    var topEnd = 0
    if isTop and topStart != lastStart
        lastStart := topStart
        [Line, A, B] = drawLL(topStart, bar_index, topPrice, "Top 1", "Top 2", color.lime)
        topLine := Line
        topA := A
        topB := B
        alert("Double Top In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossunder(close, topLine.get_y2()) and extendSignal
    topLine.set_x2(bar_index)
    label.new(bar_index, high, style = label.style_label_down, color=color.red)
    alert("Double Top Breakdown In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossover(close, topLine.get_y2()) and extendSignal
    topLine.set_x2(bar_index)
    label.new(bar_index, low, style = label.style_label_up, color=color.green)
    alert("Double Top Breakout In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

// ////////////////////////// Bottom Calculation //////////////////////////////////////////////////////    
bottomPrice = 0.0
isBottom = false
var line bottomLine = na
var label bottomA = na
var label bottomB = na

if inRange
    bottomStart = bottomIndex.last()
    bottomPrice := bottom.last()
    
    if bottomPrice > bottom.middlePrice() and bottomIndex.middleIndex() > topIndex.first()
        bottomPrice := bottom.middlePrice()
        bottomStart := bottomIndex.middleIndex()
    
    min_index = bottom.indexof(bottom.min())
    if bottomPrice > bottom.min() and bottomIndex.get(min_index) > topIndex.first()
        bottomPrice := bottom.min()
        bottomStart := bottomIndex.get(min_index)
        
    isBottom := close <= bottomPrice and close[1] > bottomPrice and high > bottomPrice and top.last() < top.middlePrice()

    var bottomEnd = 0
    var lastStart = 0

    if isBottom and  bottomStart != lastStart
        lastStart := bottomStart
        [Line, A, B] = drawLL(bottomStart, bar_index, bottomPrice, "Bottom 1", "Bottom 2", color.red, label.style_label_up)
        bottomLine := Line
        bottomA := A
        bottomB := B
        alert("Double Bottom In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossunder(close, bottomLine.get_y2()) and extendSignal
    bottomLine.set_x2(bar_index)
    label.new(bar_index, high, style = label.style_label_down, color=color.red)
    alert("Double Bottom Breakdown In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

if  ta.crossover(close, bottomLine.get_y2()) and extendSignal
    bottomLine.set_x2(bar_index)
    label.new(bar_index, low, style = label.style_label_up, color=color.green)
    alert("Double Bottom Breakout In: "+str.tostring(syminfo.ticker), alert.freq_once_per_bar_close)

5. Comments

  • Use // to add comments.

  • Comments can be inline or on a separate line.

  • Example:

    // This is a comment
plot(close) // Inline comment

6. Line Wrapping

  • Long lines can be split across multiple lines.

  • Wrapped lines should not use indentation that is a multiple of 4 spaces.

  • Example:

    plot(ta.correlation(src, ovr, length),
 color = color.new(color.purple, 40),
 style = plot.style_area)

7. Compiler Annotations

Special comments for instructions:

  • Version: //@version=6
  • Description: //@description
  • Function Parameters: //@param, //@returns
  • User-defined Types: //@type, //@field

8. Example Scripts

  1. Indicator Example:

    //@version=6
indicator("My Indicator")
plot(close)

  2. Strategy Example:

    //@version=6
strategy("My Strategy", overlay=true)
if ta.crossover(ta.sma(close, 14), ta.sma(close, 28))
    strategy.entry("Long Entry", strategy.long)

9. Advanced Features

  • Collapsible Code Regions:

    Use //#region and //#endregion to group and collapse code sections.

  • Example:

    //#region Inputs
input price = input.float(1.0, "Price")
//#endregion
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