Digifinex: fixed IsLastFromSnapshot bug (#440)

- previously it was marking the last trade in the batch as IsLastFromSnapshot even if it was not from a snapshot
- include IsLastFromSnapshot in ExchangeTrade.ToString()

Author: vslee

ExchangeSharp/API/Exchanges/Digifnex/ExchangeDigifinexAPI.cs

@@ -391,7 +391,9 @@ protected override IWebSocket OnGetTradesWebSocket(Func<KeyValuePair<string, Exc
         {
             if (callback == null)
                 return null;
-            return ConnectWebSocket(string.Empty, async (_socket, msg) =>
+			else if (marketSymbols == null || marketSymbols.Length == 0)
+				marketSymbols = GetMarketSymbolsAsync().Sync().ToArray();
+			return ConnectWebSocket(string.Empty, async (_socket, msg) =>
             {
                 // {
                 //    "method": "trades.update",
@@ -427,11 +429,12 @@ protected override IWebSocket OnGetTradesWebSocket(Func<KeyValuePair<string, Exc
                         var flags = default(ExchangeTradeFlags);
                         if (isbuy)
                             flags |= ExchangeTradeFlags.IsBuy;
-                        if (clean)
-                            flags |= ExchangeTradeFlags.IsFromSnapshot;
-                        if (i == x.Count - 1)
-                            flags |= ExchangeTradeFlags.IsLastFromSnapshot;
-
+						if (clean)
+						{
+							flags |= ExchangeTradeFlags.IsFromSnapshot;
+							if (i == x.Count - 1)
+								flags |= ExchangeTradeFlags.IsLastFromSnapshot;
+						}
                         await callback.Invoke(new KeyValuePair<string, ExchangeTrade>(
                             symbol, new ExchangeTrade
                             {
@@ -458,7 +461,7 @@ protected override IWebSocket OnGetDeltaOrderBookWebSocket(Action<ExchangeOrderB
                 return null;
             }
 
-            return ConnectWebSocket(string.Empty, (_socket, msg) =>
+			return ConnectWebSocket(string.Empty, (_socket, msg) =>
             {
                 //{
                 //  "method": "depth.update",

ExchangeSharp/Model/ExchangeTrade.cs

@@ -64,9 +64,12 @@ public bool IsBuy
         /// <returns>String</returns>
         public override string ToString()
         {
-            return string.Format("{0:s},p:{1},a:{2},{3},id:{4},{5}", 
+			StringBuilder flagsSB = new StringBuilder();
+			flagsSB.Append((Flags & ExchangeTradeFlags.IsFromSnapshot) == ExchangeTradeFlags.IsFromSnapshot ? "snap:" : "");
+			flagsSB.Append((Flags & ExchangeTradeFlags.IsLastFromSnapshot) == ExchangeTradeFlags.IsLastFromSnapshot ? "last" : "");
+			return string.Format("{0:s},p:{1},a:{2},{3},id:{4},{5}", 
 				Timestamp, Price, Amount, IsBuy ? "Buy" : "Sell",
-				Id, (Flags & ExchangeTradeFlags.IsFromSnapshot) == ExchangeTradeFlags.IsFromSnapshot ? "snap" : "");
+				Id, flagsSB);
         }
 
         /// <summary>