Most MQL5 coders construct their buying and selling robots round a core trio of features: OnInit() , OnDeinit() , and OnTick() . Whereas this basis is important, it is like making an attempt to prepare dinner a gourmand meal with solely a pot, a pan, and a single burner. The MQL5 setting presents a wealthy occasion mannequin with specialised handlers that may make your Knowledgeable Advisors (EAs) and indicators extra environment friendly, interactive, and highly effective.
By venturing past the fundamentals, you possibly can construct EAs that do not depend on each single tick, create dynamic consumer interfaces instantly on the chart, and even monitor and react to buying and selling exercise from different sources. Let’s discover three of essentially the most highly effective—and underutilized—occasion handlers: OnTimer() , OnChartEvent() , and OnTradeTransaction() .
Ditch the Tick: Constructing EAs with OnTimer()
The OnTick() occasion handler is the default workhorse for many EAs, executing its logic each time a brand new value quote arrives. That is nice for high-frequency methods however is extremely inefficient and pointless for methods designed for larger timeframes like H1, H4, or D1. Why examine your logic a number of instances a second while you solely care in regards to the state of a brand new bar as soon as an hour?
The OnTimer() occasion handler solves this drawback. It permits you to create a customized, periodic set off in your code, fully impartial of incoming ticks. 🕒
How It Works
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Set the Timer: In your OnInit() perform, you name EventSetTimer(seconds) . This tells the terminal to start out producing a timer occasion each specified variety of seconds.
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Execute the Logic: You place your buying and selling logic contained in the OnTimer() perform. This perform will now be referred to as on the interval you outlined.
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Kill the Timer: In your OnDeinit() perform, you will need to name EventKillTimer() to cease the timer occasion when the EA is faraway from the chart. That is essential for stopping useful resource leaks.
Instance: A Non-Ticking EA for Larger Timeframes
Let’s construct a easy EA that checks for a brand new bar on the H1 timeframe each minute, reasonably than on each tick.
#property copyright "Copyright 2025, EAHQ" #property hyperlink "https://www.mql5.com/en/customers/michael4308" #property model "1.00" datetime lastBarTime = 0; int OnInit() { EventSetTimer(60); Print("Timer EA Initialized. Checking for brand new H1 bar each minute."); return(INIT_SUCCEEDED); } void OnDeinit(const int motive) { EventKillTimer(); Print("Timer EA Eliminated. Timer stopped."); } void OnTimer() { datetime newBarTime = (datetime)SeriesInfoInteger(_Symbol, PERIOD_H1, SERIES_LASTBAR_DATE); if(newBarTime > lastBarTime) { lastBarTime = newBarTime; Print("New H1 Bar Detected at: ", TimeToString(newBarTime)); } } void OnTick() { }
Through the use of OnTimer() , this EA is way more environment friendly. It solely consumes CPU assets as soon as a minute, leaving your terminal extra responsive and decreasing the processing load, which is very vital when operating a number of EAs.
Making Charts Interactive with OnChartEvent()
Have you ever ever needed to let a consumer draw a line on a chart to set a take-profit degree or drag a rectangle to outline a buying and selling zone? The OnChartEvent() handler is your gateway to creating wealthy, interactive chart instruments. 🎨
This perform is a grasp listener that captures a variety of consumer interactions with the chart, reminiscent of mouse clicks, key presses, and—most powerfully—interactions with graphical objects.
How It Works
The OnChartEvent() perform receives a number of parameters, however a very powerful are:
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id : The kind of occasion that occurred (e.g., a key was pressed, an object was created).
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lparam , dparam , sparam : Parameters containing detailed details about the occasion. Their that means will depend on the id .
For object interactions, you may usually examine for these occasion IDs:
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CHARTEVENT_OBJECT_CREATE : Fired when a consumer finishes drawing a brand new object.
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CHARTEVENT_OBJECT_DRAG : Fired when a consumer drags an object throughout the chart.
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CHARTEVENT_OBJECT_CLICK : Fired when a consumer clicks on an object.
Instance: Setting a Take-Revenue Stage with a Line
Let’s create an indicator that permits the consumer to attract a horizontal line. The indicator will then learn the worth degree of that line and print it to the Consultants log, simulating how an EA may use it to set a Take-Revenue.
#property copyright "Copyright 2025, EAHQ" #property indicator_chart_window void OnChartEvent(const int id, const lengthy &lparam, const double &dparam, const string &sparam) { if(id == CHARTEVENT_OBJECT_CREATE) { Print("Object Created: ", sparam); if(ObjectType(sparam) == OBJ_HLINE) { double priceLevel = ObjectGetDouble(0, sparam, OBJPROP_PRICE, 0); Print("Take-Revenue degree set by HLine '", sparam, "' at value: ", DoubleToString(priceLevel, _Digits)); } } if(id == CHARTEVENT_OBJECT_DRAG) { if(ObjectType(sparam) == OBJ_HLINE) { double priceLevel = ObjectGetDouble(0, sparam, OBJPROP_PRICE, 0); Remark("Present TP Stage: ", DoubleToString(priceLevel, _Digits)); } } }
This easy instance opens up a world of potentialities for creating intuitive, user-friendly buying and selling instruments that bridge the hole between handbook evaluation and automatic execution.
The Final Watchdog: OnTradeTransaction()
What in case your EA must learn about the whole lot occurring in your buying and selling account? This contains handbook trades you place, trades executed by different EAs, and even actions taken by your dealer. The OnTradeTransaction() occasion handler is the last word watchdog, supplying you with real-time perception into all buying and selling exercise. 🕵️
This handler is triggered every time a commerce transaction happens on the account, reminiscent of inserting an order, modifying a stop-loss, closing a place, or a deal being executed.
How It Works
The OnTradeTransaction() perform receives three arguments:
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trans : An MqlTradeTransaction construction containing detailed details about the transaction (sort, order ticket, value, quantity, and so on.).
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request : The unique MqlTradeRequest that initiated this transaction.
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consequence : The MqlTradeResult of executing the request.
You possibly can examine the trans.sort subject to grasp what sort of transaction simply occurred. A standard and really helpful sort is TRADE_TRANSACTION_DEAL_ADD , which alerts {that a} new deal has been added to the account historical past (i.e., a commerce was executed).
Instance: Monitoring and Logging All New Trades
This is an EA that does nothing however monitor the account. When any new commerce (deal) is executed—whether or not by this EA, one other EA, or manually—it logs the small print.
#property copyright "Copyright 2025, EAHQ" #property model "1.00" void OnTradeTransaction(const MqlTradeTransaction &trans, const MqlTradeRequest &request, const MqlTradeResult &consequence) { if(trans.sort == TRADE_TRANSACTION_DEAL_ADD) { ulong deal_ticket = trans.deal; if(HistoryDealSelect(deal_ticket)) { lengthy deal_type = HistoryDealGetInteger(deal_ticket, DEAL_TYPE); lengthy deal_magic = HistoryDealGetInteger(deal_ticket, DEAL_MAGIC); double deal_volume = HistoryDealGetDouble(deal_ticket, DEAL_VOLUME); string deal_symbol = HistoryDealGetString(deal_ticket, DEAL_SYMBOL); PrintFormat("New Deal Executed: Ticket #%d, Image: %s, Kind: %s, Quantity: %.2f, Magic: %d", deal_ticket, deal_symbol, (deal_type == DEAL_TYPE_BUY ? "Purchase" : "Promote"), deal_volume, deal_magic); } } } void OnInit() {} void OnDeinit(const int motive) {} void OnTick() {}
This handler is extremely highly effective. You possibly can construct:
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A Commerce Supervisor: An EA that mechanically applies stop-loss and take-profit ranges to any commerce opened on the account, no matter its supply.
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An Fairness Protector: An EA that displays for brand new offers and closes all open positions if the account drawdown exceeds a sure threshold.
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A Synchronization Device: An EA that copies trades from one account to a different in real-time.
By mastering these superior occasion handlers, you elevate your MQL5 coding from easy automation to creating really clever, environment friendly, and interactive buying and selling techniques. Go forward and experiment—your buying and selling instruments won’t ever be the identical once more.
