Singleton Example in MetaTrader
Info
The Singleton Example in MetaTrader is a Expert Advisor for MetaTrader 4 that this is a practical demonstration of a singleton code implementation in metatrader. The objective is to showcase how to create a singleton object, ensuring that only one instance of a particular object can exist.
Usage
This tool is typically used for automated trading on major forex pairs and gold.
Platform
This Expert Advisor works exclusively on MetaTrader 4 (both build 600+ and newer versions).
Setup
Place the downloaded file in MQL4/Experts folder via File ? Open Data Folder in MetaTrader 4.
How to Install and Use Singleton Example in MetaTrader
1. Installation: Open the "File" menu, select "Open Data Folder," navigate to MQL/Experts, paste your file, and restart the terminal.
2. Activation: Drag the EA from the Navigator onto a chart, ensure "Allow live trading" is checked in the Common tab, and verify the AutoTrading button is green.
3. Optimization: Right-click your chart, choose "Expert List," click "Properties" to adjust inputs, and save your preferred setup as a set file for future use.
4. Maintenance: Regularly check the "Experts" tab in the terminal window to monitor trade logs and potential execution errors.
Frequently Asked Questions
Q: Why is my EA not opening trades? A: Check the "AutoTrading" button, ensure "Allow live trading" is enabled, and verify your broker allows automated trading on your account type.
Q: Can I run multiple EAs on one chart? A: No, each chart can only host one active EA; however, you can open multiple charts for different currency pairs to run several EAs.
Q: What does the "smiley face" icon mean? A: A smiley face in the top-right corner of the chart indicates the EA is successfully running; a frowny face means it is disabled.
What this tool does
This is a practical demonstration of a singleton code implementation in MetaTrader.
Typical Use Case
This Expert Advisor excels in automated trading and technical analysis on MetaTrader 4.
Compatible Platform & Setup
This Expert Advisor works on MetaTrader 4. Place the file in the MQL4/Experts folder and restart the terminal.
Description & Settings
Related: prototype-ix: a multicurrency ea example - another powerful expert for MetaTrader 4 traders.
This is a practical demonstration of a singleton code implementation in MetaTrader. The objective is to showcase how to create a singleton object, ensuring that only one instance of a particular object can exist.Also recommended: Object Label Example EA for MT4/MT5 - similar expert with strong performance on MetaTrader 4.
In this example, the constructor is made private, and assignment and copy operations are restricted to achieve this singularity. This approach enhances code clarity and ensures that the object's type is distinct.
While some developers may have reservations about singletons, modern compiler advancements have addressed many technical concerns. This example demonstrates the successful implementation of a singleton in the MetaTrader environment, showcasing its effectiveness and relevance in 2026.
Feel free to contribute improvements or share your thoughts on this code snippet.
You may also like: Object Label Example for MetaTrader - excellent alternative for expert users on MetaTrader 4.
Source Code
#property copyright "robotfx"
#property link "https://robotfx.org"
#property version "1.00"
#property strict
class cyolinux
{
private:
static cyolinux *m_yolinux; // static pointer to the only instance of exposure manager
int m_tickcounter; // a variable so we can have the object do something (count)
string m_counterdisplay; // a place to store a screen display object name; see it be created and destroyed.......
⚠ Limitations & Risk Warning
- This tool is provided for educational and testing purposes only.
- Past performance does not guarantee future results.
- Trading involves substantial risk of loss. Use on a demo account first.
- Results may vary depending on market conditions, broker, and settings.
- We recommend thorough backtesting and forward testing before using with real funds.