From a8cb9c360767b8cef8336811e0b5a2334aa63900 Mon Sep 17 00:00:00 2001
From: mort5161 <mnielsen@esri.com>
Date: Wed, 12 Nov 2014 10:58:58 -0800
Subject: [PATCH] Improved parsing of values not available in NMEA message

---
 src/NmeaParser.Shared/Nmea/Gps/GPGGA.cs       |  6 ++---
 src/NmeaParser.Shared/Nmea/Gps/GPRMC.cs       | 23 +++++++++++--------
 .../Nmea/Gps/Garmin/PGRME.cs                  |  6 ++---
 src/NmeaParser.Shared/Nmea/NmeaMessage.cs     | 13 +++++++++++
 4 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/src/NmeaParser.Shared/Nmea/Gps/GPGGA.cs b/src/NmeaParser.Shared/Nmea/Gps/GPGGA.cs
index be3704b..d25d25c 100644
--- a/src/NmeaParser.Shared/Nmea/Gps/GPGGA.cs
+++ b/src/NmeaParser.Shared/Nmea/Gps/GPGGA.cs
@@ -49,10 +49,10 @@ namespace NmeaParser.Nmea.Gps
 			Longitude = NmeaMessage.StringToLongitude(message[3], message[4]);
 			Quality =  (FixQuality)int.Parse(message[5], CultureInfo.InvariantCulture);
 			NumberOfSatellites = int.Parse(message[6], CultureInfo.InvariantCulture);
-			Hdop = double.Parse(message[7], CultureInfo.InvariantCulture);
-			Altitude = double.Parse(message[8], CultureInfo.InvariantCulture);
+			Hdop = NmeaMessage.StringToDouble(message[7]);
+			Altitude = NmeaMessage.StringToDouble(message[8]);
 			AltitudeUnits = message[9];
-			HeightOfGeoid = double.Parse(message[10], CultureInfo.InvariantCulture);
+			HeightOfGeoid = NmeaMessage.StringToDouble(message[10]);
 			HeightOfGeoidUnits = message[11];
 			if (message[0].Length == 6)
 			{
diff --git a/src/NmeaParser.Shared/Nmea/Gps/GPRMC.cs b/src/NmeaParser.Shared/Nmea/Gps/GPRMC.cs
index 1919c02..8fadae0 100644
--- a/src/NmeaParser.Shared/Nmea/Gps/GPRMC.cs
+++ b/src/NmeaParser.Shared/Nmea/Gps/GPRMC.cs
@@ -31,19 +31,22 @@ namespace NmeaParser.Nmea.Gps
 	{
 		protected override void LoadMessage(string[] message)
 		{
-			FixTime = new DateTime(int.Parse(message[8].Substring(4, 2)) + 2000,
-								   int.Parse(message[8].Substring(2, 2)),
-								   int.Parse(message[8].Substring(0, 2)),
-								   int.Parse(message[0].Substring(0, 2)),
-								   int.Parse(message[0].Substring(2, 2)),
-								   int.Parse(message[0].Substring(4, 2)), DateTimeKind.Utc);
+			if (message[8].Length == 6 && message[0].Length == 6)
+			{
+				FixTime = new DateTime(int.Parse(message[8].Substring(4, 2)) + 2000,
+									   int.Parse(message[8].Substring(2, 2)),
+									   int.Parse(message[8].Substring(0, 2)),
+									   int.Parse(message[0].Substring(0, 2)),
+									   int.Parse(message[0].Substring(2, 2)),
+									   int.Parse(message[0].Substring(4, 2)), DateTimeKind.Utc);
+			}
 			Active = (message[1] == "A");
 			Latitude = NmeaMessage.StringToLatitude(message[2], message[3]);
 			Longitude = NmeaMessage.StringToLongitude(message[4], message[5]);
-			Speed = double.Parse(message[6], CultureInfo.InvariantCulture);
-			Course = double.Parse(message[7], CultureInfo.InvariantCulture);
-			MagneticVariation = double.Parse(message[9], CultureInfo.InvariantCulture);
-			if (message[10] == "W")
+			Speed = NmeaMessage.StringToDouble(message[6]);
+			Course = NmeaMessage.StringToDouble(message[7]);
+			MagneticVariation = NmeaMessage.StringToDouble(message[9]);			
+			if (!double.IsNaN(MagneticVariation) && message[10] == "W")
 				MagneticVariation *= -1;
 		}
 
diff --git a/src/NmeaParser.Shared/Nmea/Gps/Garmin/PGRME.cs b/src/NmeaParser.Shared/Nmea/Gps/Garmin/PGRME.cs
index e5d4c62..b0ae016 100644
--- a/src/NmeaParser.Shared/Nmea/Gps/Garmin/PGRME.cs
+++ b/src/NmeaParser.Shared/Nmea/Gps/Garmin/PGRME.cs
@@ -31,11 +31,11 @@ namespace NmeaParser.Nmea.Gps.Garmin
 	{
 		protected override void LoadMessage(string[] message)
 		{
-			HorizontalError = double.Parse(message[0], CultureInfo.InvariantCulture);
+			HorizontalError = NmeaMessage.StringToDouble(message[0]);
 			HorizontalErrorUnits = message[1];
-			VerticalError = double.Parse(message[2], CultureInfo.InvariantCulture);
+			VerticalError = NmeaMessage.StringToDouble(message[2]);
 			VerticalErrorUnits = message[3];
-			SphericalError = double.Parse(message[4], CultureInfo.InvariantCulture);
+			SphericalError = NmeaMessage.StringToDouble(message[4]);
 			SphericalErrorUnits = message[5];
 		}
 
diff --git a/src/NmeaParser.Shared/Nmea/NmeaMessage.cs b/src/NmeaParser.Shared/Nmea/NmeaMessage.cs
index c856a9a..f769755 100644
--- a/src/NmeaParser.Shared/Nmea/NmeaMessage.cs
+++ b/src/NmeaParser.Shared/Nmea/NmeaMessage.cs
@@ -137,5 +137,18 @@ namespace NmeaParser.Nmea
 			}
 			catch { return double.NaN; }
 		}
+		internal static double StringToDouble(string value)
+		{
+			try
+			{
+				double result = double.NaN;
+				if(double.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out result))
+				{
+					return result;
+				}
+				return double.NaN;
+			}
+			catch { return double.NaN; }
+		}
 	}
 }