Leaf Input Parsing complete

Core/Services/ParsedObjectFactory.cs

@@ -0,0 +1,159 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using Fasterflect;
+
+namespace LeafWeb.Core.Services
+{
+	public static class ParsedObjectFactory<T> where T : new()
+	{
+		private static PropertyInfo[] GetProperties()
+		{
+			var propertyInfos = typeof(T).Properties();
+			return propertyInfos.Where(p => p.HasAttribute<ParseInfoAttribute>()).ToArray();
+		}
+
+		/// <summary>
+		/// Create an object type T filling properties from the given title values
+		/// </summary>
+		/// <param name="titleValues">Colon separated title: values</param>
+		public static T Create(string[] titleValues)
+		{
+			var properties = GetProperties();
+			var obj = new T();
+			// take each of the 
+			for (var index = 0; index < titleValues.Length; index++)
+			{
+				PropertyInfo property = null;
+				string value = null;
+
+				var lineNumber = index + 1;
+				var row = titleValues[index];
+				var split = row.Split(':');
+				if (split.Length > 1)
+				{
+					// handles case for "Title : Value"
+					var title = split[0].Trim();
+					value = split[1].Trim();
+					property =
+						properties
+						.FirstOrDefault(p => p.Attribute<ParseInfoAttribute>().IsTitleMatch(title));
+				}
+				if (property == null)
+				{
+					// handles case for row number, i.e. "Value"
+					value = row.Trim();
+					property =
+						properties
+						.FirstOrDefault(p => p.Attribute<ParseInfoAttribute>().IsPositionMatch(lineNumber));
+				}
+
+				if (property != null)
+				{
+					object convertedVal;
+					if (!TryConvertValue(property, value, out convertedVal))
+						throw new ParseException(string.Format("Cannot convert value '{0}' for {1} at line number {2}", value, property.Name, lineNumber));
+					property.Set(obj, convertedVal);
+				}
+			}
+			return obj;
+		}
+
+		public static T[] Create(string[] titles, string[][] valueArrays)
+		{
+			var properties = GetProperties();
+			var objs = new T[valueArrays.Length];
+
+			for (var vIndex = 0; vIndex < valueArrays.Length; vIndex++)
+			{
+				var obj = new T();
+				var values = valueArrays[vIndex];
+				for (var tIndex = 0; tIndex < titles.Length; tIndex++)
+				{
+					var title = titles[tIndex];
+					var value = values[tIndex];
+					var position = tIndex + 1;
+
+					if (IsMissingValue(value))
+						continue;
+
+					var property = MatchProperty(properties, title, position);
+
+					if (property != null)
+					{
+						object convertedVal;
+						if (!TryConvertValue(property, value, out convertedVal))
+							throw new ParseException(string.Format("Cannot convert value '{0}' for {1} in position {2}", value, property.Name, position));
+						property.Set(obj, convertedVal);
+					}
+				}
+				objs[vIndex] = obj;
+			}
+			return objs;
+		}
+
+		public static T Create(Tuple<string, string>[] titleValues)
+		{
+			var properties = GetProperties();
+			var obj = new T();
+
+			for (var index = 0; index < titleValues.Length; index++)
+			{
+				var item = titleValues[index];
+				var position = index + 1;
+				var title = item.Item1.Trim();
+				var value = item.Item2.Trim();
+
+				if (IsMissingValue(value))
+					continue;
+
+				var property = MatchProperty(properties, title, position);
+
+				if (property != null)
+				{
+					object convertedVal;
+					if (!TryConvertValue(property, value, out convertedVal))
+						throw new ParseException(string.Format("Cannot convert value '{0}' for {1} in position {2}", value, property.Name, position));
+					property.Set(obj, convertedVal);
+				}
+			}
+			return obj;
+		}
+
+		private static bool IsMissingValue(string value)
+		{
+			return string.IsNullOrEmpty(value) || value == "NA" || value == "-9999";
+		}
+
+		private static PropertyInfo MatchProperty(PropertyInfo[] properties, string title, int position)
+		{
+			var property =
+				properties
+				.FirstOrDefault(p => p.Attribute<ParseInfoAttribute>().IsTitleMatch(title));
+
+			if (property == null)
+			{
+				property =
+					properties
+					.FirstOrDefault(p => p.Attribute<ParseInfoAttribute>().IsPositionMatch(position));
+			}
+			return property;
+		}
+
+		private static bool TryConvertValue(PropertyInfo property, object value, out object convertedValue)
+		{
+			try
+			{
+				// http://stackoverflow.com/questions/3531318/convert-changetype-fails-on-nullable-types
+				var t = Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType;
+				convertedValue = Convert.ChangeType(value, t);
+			}
+			catch (Exception)
+			{
+				convertedValue = null;
+				return false;
+			}
+			return true;
+		}
+	}
+}