Streaming Real-Time Quotes for a Symbol

Request: subscribe to real‑time bid/ask price updates for a given symbol Opens a streaming channel to receive tick‑by‑tick quotes as the market changes.

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Code Example

// --- Quick use (service wrapper) ---
// Subscribes to ticks for a single symbol. Exits on first tick or after the timeout.
await _service.ShowRealTimeQuotes("EURUSD", timeoutSeconds: 5);

// --- Low-level (direct account call) ---
// Preconditions: account is connected via ConnectByServerName/ConnectByHostPort.
// Tip: always pass a CancellationToken; streams are infinite by design.
using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
await foreach (var tick in _mt4.OnSymbolTickAsync(new[] { "EURUSD" }, cts.Token))
{
    var q = tick.SymbolTick;
    if (q == null) continue;

    Console.WriteLine($"Tick: {q.Symbol} {q.Bid}/{q.Ask} @ {q.Time}");
    break; // demo: leave after the first tick
}

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Method Signatures

Service wrapper

Task ShowRealTimeQuotes(
    string symbol,
    int timeoutSeconds = 5,
    CancellationToken ct = default
)

Direct stream

IAsyncEnumerable<SymbolTickData> OnSymbolTickAsync(
    string[] symbols,
    [EnumeratorCancellation] CancellationToken cancellationToken = default
)

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🔽 Input

Wrapper (ShowRealTimeQuotes)

Parameter	Type	Required	Description
symbol	string	✅	Symbol to subscribe (e.g., "EURUSD").
timeoutSeconds	int	❌	Upper bound to wait for the first tick before stopping (default: 5).
ct	CancellationToken	❌	External cancellation (linked with internal timeout).

Direct (OnSymbolTickAsync)

Parameter	Type	Required	Description
symbols	string[]	✅	One or more symbols (even a single one like new[]{"EURUSD"}).
cancellationToken	CancellationToken	❌	Cancels the infinite stream.

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⬆️ Output

Both variants deliver items of type SymbolTickData, which contains a QuoteData payload:

Structure: QuoteData

Field	Type	Description
Symbol	string	Symbol name
Bid	double	Current bid price
Ask	double	Current ask price
Time	string	UTC timestamp of the tick

In the wrapper, the first received tick is printed to console and the method exits.

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🎯 Purpose

Use this to receive live market data for a symbol. Typical scenarios:

• Real‑time quote panels
• Alert engines that trigger on price movement
• Feeding pricing into automated strategies/UI overlays

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🧩 Notes & Tips

• Streams are infinite. Always pass a CancellationToken (wrapper adds a timeout guard).
• Server Cancelled != app cancellation. Some servers respond with StatusCode.Cancelled when finalizing a subscription; client code treats this as graceful completion unless your token was cancelled with an error.
• Reconnects. Transient transport issues (Unavailable, DeadlineExceeded, Internal) are retried by the client’s internal stream wrapper with exponential backoff.
• Many symbols? Prefer a single subscription with multiple symbols over many per‑symbol subscriptions.

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⚠️ Pitfalls

• No first tick. If the market is closed/illiquid or symbol is wrong, you may hit the timeout without any tick. Validate symbol names exactly as returned by SymbolsAsync().
• Over‑subscribing. Creating lots of simultaneous per‑symbol streams can exhaust chart/session limits on the terminal. Batch symbols where possible.

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🧪 Testing

• Happy path: You should see at least one tick during active market hours.
• Timeout path: Use a tiny timeoutSeconds to verify graceful stop without exceptions.
• Cancel path: Cancel the token and ensure the app exits the loop cleanly without leaking tasks.