Best Practices for Writing Code for MetaTrader Platform.

1. Use Clear and Concise Naming Conventions

When writing code for MetaTrader, it is important to use clear and concise naming conventions for variables, functions, and classes. This will help you and other developers understand the code more easily and avoid confusion. For example, instead of using abbreviations or single-letter variable names, use descriptive names that indicate what the variable represents.

Example:

// Good Naming Convention
double takeProfit;
double stopLoss;

// Poor Naming Convention
double tp;
double sl;

2. Break Down Complex Code into Smaller Functions

Breaking down complex code into smaller functions makes it easier to understand, test, and maintain. When writing functions, it is important to use clear and descriptive names that indicate what the function does.

Example:

// Good Function
double calculateEMA(double price[], int period) {
    double ema = 0;
    for (int i = 0; i < period; i++) {
        ema += price[i];
    }
    ema /= period;
    return ema;
}

// Poor Function
double ema(double p[], int n) {
    double e = 0;
    for (int i = 0; i < n; i++) {
        e += p[i];
    }
    e /= n;
    return e;
}

3. Use Comments to Explain Code

Using comments to explain code is essential for making it more readable and understandable. Comments should be used to explain what the code does, why it does it, and any limitations or assumptions it makes.

Example:

// Calculate Simple Moving Average
// price[]: array of prices
// period: number of periods to calculate SMA
double calculateSMA(double price[], int period) {
    double sum = 0;
    for (int i = 0; i < period; i++) {
        sum += price[i];
    }
    double sma = sum / period;
    return sma;
}

4. Use Indentation and Formatting to Improve Readability

Proper indentation and formatting can improve the readability of the code and make it easier to follow the logical flow of the program. Use consistent indentation and formatting throughout your code.

Example:

// Good Formatting
if (condition) {
    // Code Block
    for (int i = 0; i < n; i++) {
        // Code Block
    }
} else {
    // Code Block
}

// Poor Formatting
if(condition){for(int i=0;i<n;i++){}}else{}

Code Examples

1. Simple Moving Average Indicator

This code snippet calculates the simple moving average of a price array and plots it as a line on the chart.

#property indicator_chart_window
#property indicator_buffers 1

extern int period = 14;

double smaBuffer[];

void calculateSMA() {
    int limit;
    int counted_bars = IndicatorCounted();
    if (counted_bars > 0) {
        limit = Bars - counted_bars;
    } else {
        limit = Bars - period - 1;
    }

    for (int i = limit; i >= 0; i