Organizing EA Logic Outside OnTick() (MQL4)

Lesson Goal

In this lesson, you will learn:

• What OnTick() is really meant to do
• Why putting all logic inside OnTick() causes problems
• How to move logic into clear, reusable functions
• How professional EAs are organized from top to bottom

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1) What OnTick() Is (And What It Is NOT)

OnTick() runs every time a new price tick arrives. That can be many times per second.

Because of this, OnTick() should:

• Decide what needs to run
• Decide when it should run

OnTick() should NOT:

• Contain hundreds of lines of logic
• Do heavy calculations directly
• Mix entry logic, exits, and filters together

Think of OnTick() as a traffic controller, not a worker.

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2) The Common Beginner Problem

Most beginners start with something like this:

void OnTick()
{
   // Spread check
   double spread = MarketInfo(Symbol(), MODE_SPREAD);
   if(spread > 20) return;

   // Time filter
   if(Hour() < 8 || Hour() > 16) return;

   // Entry logic
   if(OrdersTotal() == 0)
   {
      // OrderSend logic
   }

   // Trade management
   if(OrdersTotal() > 0)
   {
      // trailing stop, exits, etc.
   }
}

This code works, but it quickly becomes:

• Hard to read
• Hard to debug
• Hard to expand

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3) The Core Rule: OnTick() Should Read Like English

A well-structured OnTick() should be short and readable.

You should be able to understand it without scrolling.

Example: Clean OnTick()

void OnTick()
{
   UpdateTradingRules();
   if(!TradingAllowed) return;

   ManageOpenTrades();
   LookForEntries();
}

If you can read OnTick() like a checklist, you are doing it right.

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4) Step 1: Move Rule Checks Out of OnTick()

Rule checks include:

• Spread filters
• Time filters
• Daily profit / loss limits

Instead of checking these directly in OnTick(), move them into a single function.

Example: Rule Update Function

// Global state
bool TradingAllowed = true;

void UpdateTradingRules()
{
   TradingAllowed = true;

   if(MarketInfo(Symbol(), MODE_SPREAD) > 20)
      TradingAllowed = false;

   if(Hour() < 8 || Hour() > 16)
      TradingAllowed = false;
}

Now OnTick() simply asks:

if(!TradingAllowed) return; 

//Meaning if TradingAllowed==False go back to the start and try again... YOU SHALL NOT PASS!

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5) Step 2: Separate Trade Management from Entries

Managing open trades and opening new trades are two very different jobs.

They should NEVER be mixed in the same block of code.

Example: Two Separate Functions

void ManageOpenTrades()
{
   // trailing stops, exits, breakeven logic
}

void LookForEntries()
{
   if(OrdersTotal() > 0) return;

   // entry logic here
}

This prevents:

• Accidental double entries
• Entry logic running while trades are being managed
• Hard-to-find logic bugs

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6) Optional but Powerful: Run Logic Once Per Bar

Many EA calculations do not need to run on every tick.

A common professional technique is to run logic once per candle.

Example: New Bar Detection

datetime LastBarTime = 0;

bool IsNewBar()
{
   if(Time[0] != LastBarTime)
   {
      LastBarTime = Time[0];
      return(true);
   }
   return(false);
}

Now OnTick() becomes even cleaner:

void OnTick()
{
   UpdateTradingRules();
   if(!TradingAllowed) return;

   if(IsNewBar())
   {
      ManageOpenTrades();
      LookForEntries();
   }
}

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7) Full EA Skeleton (Everything in One Place)

This shows the recommended structure for a beginner-friendly, professional-quality EA.

//==============================
// GLOBAL VARIABLES
//==============================
bool TradingAllowed = true;
datetime LastBarTime = 0;

//==============================
// ONTICK (traffic controller)
//==============================
void OnTick()
{
   UpdateTradingRules();
   if(!TradingAllowed) return;

   if(IsNewBar())
   {
      ManageOpenTrades();
      LookForEntries();
   }
}

//==============================
// LOGIC FUNCTIONS
//==============================

void UpdateTradingRules()
{
   TradingAllowed = true;

   if(MarketInfo(Symbol(), MODE_SPREAD) > 20)
      TradingAllowed = false;

   if(Hour() < 8 || Hour() > 16)
      TradingAllowed = false;
}

void ManageOpenTrades()
{
   // trade management logic
}

void LookForEntries()
{
   if(OrdersTotal() > 0) return;

   // entry logic
}

//==============================
// HELPER FUNCTIONS
//==============================

bool IsNewBar()
{
   if(Time[0] != LastBarTime)
   {
      LastBarTime = Time[0];
      return(true);
   }
   return(false);
}

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8) Common Beginner Mistakes

• Letting OnTick() grow too large
• Mixing entry and exit logic together
• Running heavy logic on every tick
• Copying and pasting logic instead of organizing it

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Lesson Summary

• OnTick() should be short and readable
• Move rules, entries, and management into separate functions
• One function = one job
• Use OnTick() as a controller, not a workspace

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Next Lesson

Writing Clean, Readable EA Code

We will focus on naming, spacing, comments, and structure so your EA is easy to understand months later.