🗑️ DeletePending (GoMT4)

Goal: safely delete a pending order (Buy/Sell Limit/Stop) by ticket, with small sanity checks.

Real code refs:

• Account methods: examples/mt4/MT4Account.go (e.g., OrderDelete, OrderByTicket, ShowOpenedOrders)
• Example: examples/mt4/MT4_service.go (ShowOrderDeleteExample)

---

✅ 1) Preconditions

• You have the ticket of a pending order (not a market position).
• MT4 terminal is running & connected.
• Symbol is visible in MT4 (helps avoid “symbol not found” edge cases).

---

🔎 2) Locate and verify the order (optional but safer)

ord, err := account.OrderByTicket(ctx, ticket)
if err != nil { return err }

switch ord.GetType() {
case pb.OrderType_OP_BUYLIMIT, pb.OrderType_OP_SELLLIMIT,
     pb.OrderType_OP_BUYSTOP,  pb.OrderType_OP_SELLSTOP:
    // ok, this is a pending order
default:
    return fmt.Errorf("ticket %d is not a pending order (type=%s)", ticket, ord.GetType())
}

---

🧰 3) Prepare params

Some brokers still check slippage field (points) even for delete; keep a small value for consistency.

slippage := int32(5) // points

---

🗑️ 4) Call OrderDelete

resp, err := account.OrderDelete(
    ctx,
    ticket,
    &slippage, // optional; broker-dependent
)
if err != nil {
    return fmt.Errorf("delete pending failed: %w", err)
}
fmt.Printf("✅ Pending deleted: ticket=%d symbol=%s time=%s\n",
    ticket, ord.GetSymbol(), time.Now().Format(time.RFC3339))

Internally, the account helper wraps retries on transient transport errors (codes.Unavailable).

---

⚠️ Pitfalls

• Not a pending → OrderDelete works only for pending orders; for market positions use OrderClose.
• Ticket not found → it may have been executed or canceled already; refresh open orders and history.
• Freeze level → some brokers restrict actions near market price; try again later or move price (modify) before delete.
• Timeouts → wrap in context.WithTimeout (3–6s) and retry only transport errors.

---

🔄 Variations

• Bulk delete all pendings on a symbol:

opened, err := account.ShowOpenedOrders(ctx)
if err != nil { return err }
for _, o := range opened.GetOrders() {
    if o.GetSymbol() != symbol { continue }
    switch o.GetType() {
    case pb.OrderType_OP_BUYLIMIT, pb.OrderType_OP_SELLLIMIT,
         pb.OrderType_OP_BUYSTOP,  pb.OrderType_OP_SELLSTOP:
        if _, err := account.OrderDelete(ctx, o.GetTicket(), &slippage); err != nil {
            log.Printf("delete %d failed: %v", o.GetTicket(), err)
        }
    }
}

• Conditional cleanup (good‑till‑time): if ord.GetExpiration().AsTime().Before(time.Now()) → delete.

---

📎 See also

• PlacePendingOrder.md — how to place a pending with correct price/expiry.
• ModifyOrder.md — change pending price/expiration instead of deleting.
• CloseOrder.md — for market positions.