Type Converter Enhancements

src/FlatFile.Benchmark/Converters/CsvHelperTypeConverterForCustomType.cs

@@ -14,12 +14,12 @@ public CsvHelperTypeConverterForCustomType()
 
         public string ConvertToString(CsvHelperTypeConversion.TypeConverterOptions options, object value)
         {
-            return converter.ConvertToString(value);
+            return converter.ConvertToString(value, null);
         }
 
         public object ConvertFromString(CsvHelperTypeConversion.TypeConverterOptions options, string text)
         {
-            return converter.ConvertFromString(text);
+            return converter.ConvertFromString(text, null);
         }
 
         public bool CanConvertFrom(Type type)

src/FlatFile.Benchmark/Converters/FlatFileTypeConverterForCustomType.cs

@@ -1,6 +1,7 @@
 namespace FlatFile.Benchmark.Converters
 {
     using System;
+    using System.Reflection;
     using FlatFile.Benchmark.Entities;
     using FlatFile.Core;
 
@@ -16,13 +17,13 @@ public bool CanConvertTo(Type type)
             return type == typeof (CustomType);
         }
 
-        public string ConvertToString(object source)
+        public string ConvertToString(object source, PropertyInfo sourceProperty)
         {
             var obj = (CustomType)source;
             return string.Format("{0}|{1}|{2}", obj.First, obj.Second, obj.Third);
         }
 
-        public object ConvertFromString(string source)
+        public object ConvertFromString(string source, PropertyInfo targetProperty)
         {
             var values = source.Split('|');
 

src/FlatFile.Core/Base/FlatFileEngine.cs

@@ -24,7 +24,7 @@ public abstract class FlatFileEngine<TFieldSettings, TLayoutDescriptor> : IFlatF
         /// Gets the line builder.
         /// </summary>
         /// <value>The line builder.</value>
-        protected abstract ILineBulder LineBuilder { get; }
+        protected abstract ILineBuilder LineBuilder { get; }
 
         /// <summary>
         /// Gets the line parser.

src/FlatFile.Core/Base/LineBulderBase.cs → src/FlatFile.Core/Base/LineBuilderBase.cs

@@ -1,12 +1,12 @@
 namespace FlatFile.Core.Base
 {
-    public abstract class LineBulderBase<TLayoutDescriptor, TFieldSettings> : ILineBulder
+    public abstract class LineBuilderBase<TLayoutDescriptor, TFieldSettings> : ILineBuilder
         where TLayoutDescriptor : ILayoutDescriptor<TFieldSettings>
         where TFieldSettings : IFieldSettingsContainer 
     {
         private readonly TLayoutDescriptor _descriptor;
 
-        protected LineBulderBase(TLayoutDescriptor descriptor)
+        protected LineBuilderBase(TLayoutDescriptor descriptor)
         {
             this._descriptor = descriptor;
         }
@@ -21,7 +21,7 @@ protected TLayoutDescriptor Descriptor
         protected virtual string GetStringValueFromField(TFieldSettings field, object fieldValue)
         {
             string lineValue = fieldValue != null
-                ? fieldValue.ToString()
+                ? ConvertToString(field, fieldValue)
                 : field.NullValue ?? string.Empty;
 
             lineValue = TransformFieldValue(field, lineValue);
@@ -33,5 +33,14 @@ protected virtual string TransformFieldValue(TFieldSettings field, string lineVa
         {
             return lineValue;
         }
+
+        private static string ConvertToString(TFieldSettings field, object fieldValue)
+        {
+            var converter = field.TypeConverter;
+            if (converter != null && converter.CanConvertTo(typeof(string)) && converter.CanConvertFrom(field.PropertyInfo.PropertyType))
+                return field.TypeConverter.ConvertToString(fieldValue, field.PropertyInfo);
+
+            return fieldValue.ToString();
+        }
     }
 }

src/FlatFile.Core/Base/LineParserBase.cs

@@ -1,6 +1,7 @@
 namespace FlatFile.Core.Base
 {
     using System;
+    using System.Reflection;
     using FlatFile.Core.Extensions;
 
     public abstract class LineParserBase<TLayoutDescriptor, TFieldSettings> : ILineParser
@@ -39,7 +40,7 @@ protected virtual object GetFieldValueFromString(TFieldSettings fieldSettings, s
 
             object obj;
 
-            if (!fieldSettings.TypeConverter.ConvertFromStringTo(memberValue, type, out obj))
+            if (!fieldSettings.TypeConverter.ConvertFromStringTo(memberValue, type, fieldSettings.PropertyInfo, out obj))
             {
                 obj = memberValue.Convert(type);
             }
@@ -56,11 +57,11 @@ protected virtual string TransformStringValue(TFieldSettings fieldSettingsBuilde
     public static class TypeConverterExtensions
     {
 
-        public static bool ConvertFromStringTo(this ITypeConverter converter, string source, Type targetType, out object obj)
+        public static bool ConvertFromStringTo(this ITypeConverter converter, string source, Type targetType, PropertyInfo targetProperty, out object obj)
         {
             if (converter != null && converter.CanConvertFrom(typeof(string)) && converter.CanConvertTo(targetType))
             {
-                obj = converter.ConvertFromString(source);
+                obj = converter.ConvertFromString(source, targetProperty);
                 return true;
             }
 

src/FlatFile.Core/Base/TypeConverterBase.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Reflection;
+
+namespace FlatFile.Core.Base
+{
+    /// <summary>
+    /// A generic base class for converting between strings and a given type.
+    /// </summary>
+    /// <typeparam name="TValue">The type to convert to and from a string.</typeparam>
+    public abstract class TypeConverterBase<TValue> : ITypeConverter
+    {
+        public virtual bool CanConvertFrom(Type type)
+        {
+            return type == typeof(string) || type == typeof(TValue);
+        }
+
+        public virtual bool CanConvertTo(Type type)
+        {
+            return type == typeof(string) || type == typeof(TValue);
+        }
+
+        public object ConvertFromString(string source, PropertyInfo targetProperty)
+        {
+            return ConvertFrom(source, targetProperty);
+        }
+
+        protected abstract TValue ConvertFrom(string source, PropertyInfo targetProperty);
+
+        public string ConvertToString(object source, PropertyInfo sourceProperty)
+        {
+            return ConvertTo((TValue)source, sourceProperty);
+        }
+
+        protected abstract string ConvertTo(TValue source, PropertyInfo sourceProperty);
+    }
+}

src/FlatFile.Core/DelegatingTypeConverter.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Reflection;
+
+namespace FlatFile.Core
+{
+    /// <summary>
+    /// An implementation of <see cref="ITypeConverter"/> that uses delegates for conversion.
+    /// </summary>
+    class DelegatingTypeConverter<TProperty> : ITypeConverter
+    {
+        internal Func<string, TProperty> ConversionFromString { get; set; }
+
+        internal Func<TProperty, string> ConversionToString { get; set; }
+
+        public bool CanConvertFrom(Type type)
+        {
+            return (type == typeof(string) && ConversionFromString != null) ||
+                   (type == typeof(TProperty) && ConversionToString != null);
+        }
+
+        public bool CanConvertTo(Type type)
+        {
+            return (type == typeof(string) && ConversionToString != null) ||
+                   (type == typeof(TProperty) && ConversionFromString != null);
+        }
+
+        public object ConvertFromString(string source, PropertyInfo targetProperty)
+        {
+            return ConversionFromString(source);
+        }
+
+        public string ConvertToString(object source, PropertyInfo sourceProperty)
+        {
+            return ConversionToString((TProperty)source);
+        }
+    }
+}

src/FlatFile.Core/FlatFile.Core.csproj

@@ -100,8 +100,10 @@
     <Compile Include="Base\FlatFileEngine.cs" />
     <Compile Include="Base\LayoutBase.cs" />
     <Compile Include="Base\LayoutDescriptorBase.cs" />
-    <Compile Include="Base\LineBulderBase.cs" />
+    <Compile Include="Base\LineBuilderBase.cs" />
     <Compile Include="Base\LineParserBase.cs" />
+    <Compile Include="Base\TypeConverterBase.cs" />
+    <Compile Include="DelegatingTypeConverter.cs" />
     <Compile Include="Exceptions\ParseLineException.cs" />
     <Compile Include="Extensions\ExpressionExtensions.cs" />
     <Compile Include="Extensions\FieldsSettingsExtensions.cs" />
@@ -117,7 +119,7 @@
     <Compile Include="ILayout.cs" />
     <Compile Include="ILayoutDescriptor.cs" />
     <Compile Include="ILineBuilderFactory.cs" />
-    <Compile Include="ILineBulder.cs" />
+    <Compile Include="ILineBuilder.cs" />
     <Compile Include="ILineParser.cs" />
     <Compile Include="ILineParserFactory.cs" />
     <Compile Include="ITypeConverter.cs" />

src/FlatFile.Core/IFieldSettingsConstructor.cs

@@ -1,11 +1,14 @@
 namespace FlatFile.Core
 {
     using FlatFile.Core.Base;
+    using System;
 
     public interface IFieldSettingsConstructor<out TConstructor> : IFieldSettingsContainer
         where TConstructor : IFieldSettingsConstructor<TConstructor>
     {
         TConstructor AllowNull(string nullValue);
         TConstructor WithTypeConverter<TConverter>() where TConverter : ITypeConverter;
+        TConstructor WithConversionFromString<TProperty>(Func<string, TProperty> conversion);
+        TConstructor WithConversionToString<TProperty>(Func<TProperty, string> conversion);
     }
 }

src/FlatFile.Core/ILineBulder.cs → src/FlatFile.Core/ILineBuilder.cs

@@ -1,6 +1,6 @@
 namespace FlatFile.Core
 {
-    public interface ILineBulder
+    public interface ILineBuilder
     {
         string BuildLine<T>(T entry);
     }

src/FlatFile.Core/ILineBuilderFactory.cs

@@ -5,7 +5,7 @@ namespace FlatFile.Core
     public interface ILineBuilderFactory<out TBuilder, in TLayout, TFieldSettings>
         where TFieldSettings : IFieldSettings   
         where TLayout : ILayoutDescriptor<TFieldSettings>
-        where TBuilder : ILineBulder
+        where TBuilder : ILineBuilder
     {
         TBuilder GetBuilder(TLayout layout);
     }

src/FlatFile.Core/ITypeConverter.cs

@@ -1,15 +1,16 @@
 namespace FlatFile.Core
 {
     using System;
+    using System.Reflection;
 
     public interface ITypeConverter
     {
         bool CanConvertFrom(Type type);
 
         bool CanConvertTo(Type type);
 
-        string ConvertToString(object source);
+        string ConvertToString(object source, PropertyInfo sourceProperty);
 
-        object ConvertFromString(string source);
+        object ConvertFromString(string source, PropertyInfo targetProperty);
     }
 }

src/FlatFile.Delimited/IDelimitedLineBuilder.cs

@@ -2,7 +2,7 @@
 {
     using FlatFile.Core;
 
-    public interface IDelimitedLineBuilder : ILineBulder
+    public interface IDelimitedLineBuilder : ILineBuilder
     {
     }
 }

src/FlatFile.Delimited/Implementation/DelimetedFileMultiEngine.cs

@@ -79,7 +79,7 @@ internal DelimitedFileMultiEngine(
         /// <value>The line builder.</value>
         /// <remarks>The <see cref="DelimitedFileMultiEngine"/> does not contain just a single line builder.</remarks>
         /// <exception cref="System.NotImplementedException"></exception>
-        protected override ILineBulder LineBuilder { get { throw new NotImplementedException(); } }
+        protected override ILineBuilder LineBuilder { get { throw new NotImplementedException(); } }
 
         /// <summary>
         /// Gets the line parser.

src/FlatFile.Delimited/Implementation/DelimitedFieldSettingsConstructor.cs

@@ -1,5 +1,6 @@
 namespace FlatFile.Delimited.Implementation
 {
+    using System;
     using System.Reflection;
     using FlatFile.Core;
     using FlatFile.Core.Extensions;
@@ -25,6 +26,32 @@ public IDelimitedFieldSettingsConstructor WithTypeConverter<TConverter>() where
             return this;
         }
 
+        public IDelimitedFieldSettingsConstructor WithConversionFromString<TProperty>(Func<string, TProperty> conversion)
+        {
+            if (TypeConverter == null)
+                TypeConverter = new DelegatingTypeConverter<TProperty>();
+
+            if (TypeConverter is DelegatingTypeConverter<TProperty>)
+                ((DelegatingTypeConverter<TProperty>)TypeConverter).ConversionFromString = conversion;
+            else
+                throw new InvalidOperationException("A type converter has already been explicitly set.");
+
+            return this;
+        }
+
+        public IDelimitedFieldSettingsConstructor WithConversionToString<TProperty>(Func<TProperty, string> conversion)
+        {
+            if (TypeConverter == null)
+                TypeConverter = new DelegatingTypeConverter<TProperty>();
+
+            if (TypeConverter is DelegatingTypeConverter<TProperty>)
+                ((DelegatingTypeConverter<TProperty>)TypeConverter).ConversionToString = conversion;
+            else
+                throw new InvalidOperationException("A type converter has already been explicitly set.");
+
+            return this;
+        }
+
         public IDelimitedFieldSettingsConstructor WithName(string name)
         {
             Name = name;

src/FlatFile.Delimited/Implementation/DelimitedFileEngine.cs

@@ -50,7 +50,7 @@ internal DelimitedFileEngine(
         /// Gets the line builder.
         /// </summary>
         /// <value>The line builder.</value>
-        protected override ILineBulder LineBuilder
+        protected override ILineBuilder LineBuilder
         {
             get { return _builderFactory.GetBuilder(LayoutDescriptor); }
         }

src/FlatFile.Delimited/Implementation/DelimitedLineBuilder.cs

@@ -4,7 +4,7 @@
     using FlatFile.Core.Base;
 
     public class DelimitedLineBuilder :
-        LineBulderBase<IDelimitedLayoutDescriptor, IDelimitedFieldSettingsContainer>, 
+        LineBuilderBase<IDelimitedLayoutDescriptor, IDelimitedFieldSettingsContainer>, 
         IDelimitedLineBuilder
     {
         public DelimitedLineBuilder(IDelimitedLayoutDescriptor descriptor)

src/FlatFile.FixedLength/IFixedLengthLineBuilder.cs

@@ -2,7 +2,7 @@ namespace FlatFile.FixedLength
 {
     using FlatFile.Core;
 
-    public interface IFixedLengthLineBuilder : ILineBulder
+    public interface IFixedLengthLineBuilder : ILineBuilder
     {
     }
 }

src/FlatFile.FixedLength/Implementation/FixedFieldSettingsConstructor.cs

@@ -57,5 +57,31 @@ public IFixedFieldSettingsConstructor WithTypeConverter<TConverter>() where TCon
             this.TypeConverter = ReflectionHelper.CreateInstance<TConverter>(true);
             return this;
         }
+
+        public IFixedFieldSettingsConstructor WithConversionFromString<TProperty>(Func<string, TProperty> conversion)
+        {
+            if (TypeConverter == null)
+                TypeConverter = new DelegatingTypeConverter<TProperty>();
+
+            if (TypeConverter is DelegatingTypeConverter<TProperty>)
+                ((DelegatingTypeConverter<TProperty>)TypeConverter).ConversionFromString = conversion;
+            else
+                throw new InvalidOperationException("A type converter has already been explicitly set.");
+
+            return this;
+        }
+
+        public IFixedFieldSettingsConstructor WithConversionToString<TProperty>(Func<TProperty, string> conversion)
+        {
+            if (TypeConverter == null)
+                TypeConverter = new DelegatingTypeConverter<TProperty>();
+
+            if (TypeConverter is DelegatingTypeConverter<TProperty>)
+                ((DelegatingTypeConverter<TProperty>)TypeConverter).ConversionToString = conversion;
+            else
+                throw new InvalidOperationException("A type converter has already been explicitly set.");
+
+            return this;
+        }
     }
 }

src/FlatFile.FixedLength/Implementation/FixedLengthFileEngine.cs

@@ -44,7 +44,7 @@ internal FixedLengthFileEngine(
         /// Gets the line builder.
         /// </summary>
         /// <value>The line builder.</value>
-        protected override ILineBulder LineBuilder
+        protected override ILineBuilder LineBuilder
         {
             get { return lineBuilderFactory.GetBuilder(LayoutDescriptor); }
         }