Add long-term trend period parameter to Engulfing strategy

strategies/engulfing/EngulfingBot.cs

@@ -1,6 +1,7 @@
 #region Using declarations
 using NinjaTrader.Cbi;
 using NinjaTrader.NinjaScript.Indicators;
+using System.ComponentModel.DataAnnotations;
 #endregion
 
 namespace NinjaTrader.NinjaScript.Strategies
@@ -17,10 +18,12 @@ namespace NinjaTrader.NinjaScript.Strategies
                 Description = @"Simple strategy based on the engulfing candle pattern";
                 Calculate = Calculate.OnBarClose;
                 EntriesPerDirection = 1;
+
+                LongTermTrendPeriod = 200;
             }
             else if (State == State.DataLoaded)
             {
-                LongTermTrend = SMA(200);
+                LongTermTrend = SMA(LongTermTrendPeriod);
             }
         }
 
@@ -47,5 +50,10 @@ namespace NinjaTrader.NinjaScript.Strategies
         {
             get { return Name; }
         }
+
+        [NinjaScriptProperty]
+        [Range(1, int.MaxValue)]
+        [Display(Name = "Long-Term Trend Period", GroupName = "Engulfing Bot", Order = 1)]
+        public int LongTermTrendPeriod { get; set; }
     }
 }