Support pre- and post-parsing and formatting.

CHANGELOG.md

@@ -1,3 +1,21 @@
+## 4.4.0 (2019-05-25)
+** Summary ** - Allow pre- and post- parsing and formatting on columns. Allow specifying a global `IFormatProvider` in `IOptions`.
+
+### New Features
+* The `IOptions` interface now has a `IFormatProvider FormatProvider` property. If provided, all columns will automatically use this `IFormatProvider` as their default.
+    * The `IFormatProvider` specified on a `IColumnDefinition` will override what is specified in `IOptions`.
+    * If no `IFormatProvider` is found at either level, FlatFiles defaults to `CultureInfo.CurrentInfo`, as before.
+* The `IColumnDefinition` interface now exposes four new properties:
+    * OnParsing - Fires before attempting to parse the `string` value; the logical successor to `Preprocessor`. 
+    * OnParsed - Fires after parsing the column, providing access to the parsed `object`.
+    * OnFormatting - Fires before formatting the column, providing access to the `object`.
+    * OnFormatted - Fires after formatting the column, providing access to the generated `string`.
+
+Unlike `Preprocessor`, each of the new properties have the type `Func<IColumnContext, T, T>`, providing access to the column context.
+
+### Deprecated
+Since `Preprocessor` and `OnParsing` are effectively redundant, `Preprocessor` has been marked deprecated. Please upgrade any existing code to use `OnParsing` instead. The `Preprocessor` property will be removed in the next major release (a.k.a., v5.0).
+
 ## 4.3.4 (2019-03-10)
 **Summary** - This release allows directly writing arbitrary text to the underlying `TextWriter`, for those who need it.
 

FlatFiles.Test/ColumnContextTester.cs

@@ -129,7 +129,7 @@ internal class Person
 
         internal class IndexTrackingColumn : IColumnDefinition
         {
-            private readonly IColumnDefinition columnDefinition;
+            private readonly IColumnDefinition column;
             private readonly List<int> physicalIndexes;
             private readonly List<int> logicalIndexes;
 
@@ -138,49 +138,74 @@ public IndexTrackingColumn(
                 List<int> physicalIndexes,
                 List<int> logicalIndexes)
             {
-                this.columnDefinition = columnDefinition;
+                this.column = columnDefinition;
                 this.physicalIndexes = physicalIndexes;
                 this.logicalIndexes = logicalIndexes;
             }
 
-            public string ColumnName => columnDefinition.ColumnName;
+            public string ColumnName => column.ColumnName;
 
-            public bool IsIgnored => columnDefinition.IsIgnored;
+            public bool IsIgnored => column.IsIgnored;
 
-            public bool IsNullable => columnDefinition.IsNullable;
+            public bool IsNullable => column.IsNullable;
 
             public IDefaultValue DefaultValue
             {
-                get => columnDefinition.DefaultValue;
-                set => columnDefinition.DefaultValue = value;
+                get => column.DefaultValue;
+                set => column.DefaultValue = value;
             }
 
             public INullFormatter NullFormatter
             {
-                get => columnDefinition.NullFormatter;
-                set => columnDefinition.NullFormatter = value;
+                get => column.NullFormatter;
+                set => column.NullFormatter = value;
             }
 
+            [Obsolete]
             public Func<string, string> Preprocessor
             {
-                get => columnDefinition.Preprocessor;
-                set => columnDefinition.Preprocessor = value;
+                get => column.Preprocessor;
+                set => column.Preprocessor = value;
             }
 
-            public Type ColumnType => columnDefinition.ColumnType;
+            public Func<IColumnContext, string, string> OnParsing
+            {
+                get => column.OnParsing;
+                set => column.OnParsing = value;
+            }
+
+            public Func<IColumnContext, object, object> OnParsed
+            {
+                get => column.OnParsed;
+                set => column.OnParsed = value;
+            }
+
+            public Func<IColumnContext, object, object> OnFormatting
+            {
+                get => column.OnFormatting;
+                set => column.OnFormatting = value;
+            }
+
+            public Func<IColumnContext, string, string> OnFormatted
+            {
+                get => column.OnFormatted;
+                set => column.OnFormatted = value;
+            }
+
+            public Type ColumnType => column.ColumnType;
 
             public string Format(IColumnContext context, object value)
             {
                 physicalIndexes.Add(context.PhysicalIndex);
                 logicalIndexes.Add(context.LogicalIndex);
-                return columnDefinition.Format(context, value);
+                return column.Format(context, value);
             }
 
             public object Parse(IColumnContext context, string value)
             {
                 physicalIndexes.Add(context.PhysicalIndex);
                 logicalIndexes.Add(context.LogicalIndex);
-                return columnDefinition.Parse(context, value);
+                return column.Parse(context, value);
             }
         }
     }

FlatFiles/ByteColumn.cs

@@ -40,8 +40,7 @@ public ByteColumn(string columnName)
         /// <returns>The parsed byte value.</returns>
         protected override byte OnParse(IColumnContext context, string value)
         {
-            IFormatProvider provider = FormatProvider ?? CultureInfo.CurrentCulture;
-            return Byte.Parse(value, NumberStyles, provider);
+            return Byte.Parse(value, NumberStyles, GetFormatProvider(context, FormatProvider));
         }
 
         /// <summary>
@@ -52,11 +51,12 @@ protected override byte OnParse(IColumnContext context, string value)
         /// <returns>The formatted value.</returns>
         protected override string OnFormat(IColumnContext context, byte value)
         {
+            var provider = GetFormatProvider(context, FormatProvider);
             if (OutputFormat == null)
             {
-                return value.ToString(FormatProvider ?? CultureInfo.CurrentCulture);
+                return value.ToString(provider);
             }
-            return value.ToString(OutputFormat, FormatProvider ?? CultureInfo.CurrentCulture);
+            return value.ToString(OutputFormat, provider);
         }
     }
 }

FlatFiles/ColumnDefinition.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 using FlatFiles.Properties;
 
 namespace FlatFiles
@@ -36,8 +37,29 @@ public interface IColumnDefinition
         /// <summary>
         /// Gets or sets a function used to preprocess input before trying to parse it.
         /// </summary>
+        [Obsolete("This property has been superseded by the OnParsing delegate.")]
         Func<string, string> Preprocessor { get; set; }
 
+        /// <summary>
+        /// Gets or sets a function used to pre-process input before trying to parse it.
+        /// </summary>
+        Func<IColumnContext, string, string> OnParsing { get; set; }
+
+        /// <summary>
+        /// Gets or sets a function used to post-process input after parsing it.
+        /// </summary>
+        Func<IColumnContext, object, object> OnParsed { get; set; }
+
+        /// <summary>
+        /// Gets or sets a function used to pre-process output before trying to format it.
+        /// </summary>
+        Func<IColumnContext, object, object> OnFormatting { get; set; }
+
+        /// <summary>
+        /// Gets or sets a function used to post-process output after formatting it.
+        /// </summary>
+        Func<IColumnContext, string, string> OnFormatted { get; set; }
+
         /// <summary>
         /// Gets the type of the values in the column.
         /// </summary>
@@ -139,6 +161,26 @@ public INullFormatter NullFormatter
         /// </summary>
         public Func<string, string> Preprocessor { get; set; }
 
+        /// <summary>
+        /// Gets or sets a function used to pre-process input before trying to parse it.
+        /// </summary>
+        public Func<IColumnContext, string, string> OnParsing { get; set; }
+
+        /// <summary>
+        /// Gets or sets a function used to post-process input after parsing it.
+        /// </summary>
+        public Func<IColumnContext, object, object> OnParsed { get; set; }
+
+        /// <summary>
+        /// Gets or sets a function used to pre-process output before trying to format it.
+        /// </summary>
+        public Func<IColumnContext, object, object> OnFormatting { get; set; }
+
+        /// <summary>
+        /// Gets or sets a function used to post-process output after formatting it.
+        /// </summary>
+        public Func<IColumnContext, string, string> OnFormatted { get; set; }
+
         /// <summary>
         /// Gets the type of the values in the column.
         /// </summary>
@@ -169,6 +211,21 @@ protected internal static string TrimValue(string value)
         /// <param name="value">The object to format.</param>
         /// <returns>The formatted value.</returns>
         public abstract string Format(IColumnContext context, object value);
+
+        /// <summary>
+        /// Gets the format provider to use. If the given provider is not null, it will be used.
+        /// Otherwise, the format provider set on the options object will be used. As a last resort,
+        /// the current culture specified by the operating system will be used.
+        /// </summary>
+        /// <param name="context">The current column context.</param>
+        /// <param name="formatProvider">The format provider set on the column.</param>
+        /// <returns>The format provider to use.</returns>
+        protected static IFormatProvider GetFormatProvider(IColumnContext context, IFormatProvider formatProvider)
+        {
+            return formatProvider
+                ?? context?.RecordContext.ExecutionContext.Options.FormatProvider
+                ?? CultureInfo.CurrentCulture;
+        }
     }
 
     /// <summary>
@@ -203,6 +260,10 @@ public override object Parse(IColumnContext context, string value)
             {
                 value = Preprocessor(value);
             }
+            if (OnParsing != null)
+            {
+                value = OnParsing(context, value);
+            }
             if (NullFormatter.IsNullValue(context, value))
             {
                 if (IsNullable)
@@ -212,7 +273,12 @@ public override object Parse(IColumnContext context, string value)
                 return DefaultValue.GetDefaultValue(context);  // Should we check for the expected type?
             }
             string trimmed = IsTrimmed ? TrimValue(value) : value;
-            return OnParse(context, trimmed);
+            object result = OnParse(context, trimmed);
+            if (OnParsed != null)
+            {
+                result = OnParsed(context, result);
+            }
+            return result;
         }
 
         /// <summary>
@@ -236,11 +302,20 @@ public override object Parse(IColumnContext context, string value)
         /// <returns>The formatted value.</returns>
         public override string Format(IColumnContext context, object value)
         {
+            if (OnFormatting != null)
+            {
+                value = OnFormatting(context, value);
+            }
             if (value == null)
             {
                 return NullFormatter.FormatNull(context);
             }
-            return OnFormat(context, (T)value);
+            string result = OnFormat(context, (T)value);
+            if (OnFormatted != null)
+            {
+                result = OnFormatted(context, result);
+            }
+            return result;
         }
 
         /// <summary>

FlatFiles/DateTimeColumn.cs

@@ -56,11 +56,12 @@ protected override DateTime OnParse(IColumnContext context, string value)
         /// <returns>The formatted value.</returns>
         protected override string OnFormat(IColumnContext context, DateTime value)
         {
+            var provider = GetFormatProvider(context, FormatProvider);
             if (OutputFormat == null)
             {
-                return value.ToString(FormatProvider ?? CultureInfo.CurrentCulture);
+                return value.ToString(provider);
             }
-            return value.ToString(OutputFormat, FormatProvider ?? CultureInfo.CurrentCulture);
+            return value.ToString(OutputFormat, provider);
         }
     }
 }

FlatFiles/DateTimeOffsetColumn.cs

@@ -35,7 +35,7 @@ public DateTimeOffsetColumn(string columnName)
         /// <inheritdoc />
         protected override DateTimeOffset OnParse(IColumnContext context, string value)
         {
-            var provider = FormatProvider ?? CultureInfo.CurrentCulture;
+            var provider = GetFormatProvider(context, FormatProvider);
             if (InputFormat == null)
             {
                 return DateTimeOffset.Parse(value, provider);
@@ -46,7 +46,7 @@ protected override DateTimeOffset OnParse(IColumnContext context, string value)
         /// <inheritdoc />
         protected override string OnFormat(IColumnContext context, DateTimeOffset value)
         {
-            var provider = FormatProvider ?? CultureInfo.CurrentCulture;
+            var provider = GetFormatProvider(context, FormatProvider);
             if (OutputFormat == null)
             {
                 return value.ToString(provider);

FlatFiles/DecimalColumn.cs

@@ -40,7 +40,7 @@ public DecimalColumn(string columnName)
         /// <returns>The parsed Decimal.</returns>
         protected override decimal OnParse(IColumnContext context, string value)
         {
-            var provider = FormatProvider ?? CultureInfo.CurrentCulture;
+            var provider = GetFormatProvider(context, FormatProvider);
             return Decimal.Parse(value, NumberStyles, provider);
         }
 
@@ -52,11 +52,12 @@ protected override decimal OnParse(IColumnContext context, string value)
         /// <returns>The formatted value.</returns>
         protected override string OnFormat(IColumnContext context, decimal value)
         {
+            var provider = GetFormatProvider(context, FormatProvider);
             if (OutputFormat == null)
             {
-                return value.ToString(FormatProvider ?? CultureInfo.CurrentCulture);
+                return value.ToString(provider);
             }
-            return value.ToString(OutputFormat, FormatProvider ?? CultureInfo.CurrentCulture);
+            return value.ToString(OutputFormat, provider);
         }
     }
 }

FlatFiles/DoubleColumn.cs

@@ -40,7 +40,7 @@ public DoubleColumn(string columnName)
         /// <returns>The parsed Double.</returns>
         protected override double OnParse(IColumnContext context, string value)
         {
-            var provider = FormatProvider ?? CultureInfo.CurrentCulture;
+            var provider = GetFormatProvider(context, FormatProvider);
             return Double.Parse(value, NumberStyles, provider);
         }
 
@@ -52,11 +52,12 @@ protected override double OnParse(IColumnContext context, string value)
         /// <returns>The formatted value.</returns>
         protected override string OnFormat(IColumnContext context, double value)
         {
+            var provider = GetFormatProvider(context, FormatProvider);
             if (OutputFormat == null)
             {
-                return value.ToString(FormatProvider ?? CultureInfo.CurrentCulture);
+                return value.ToString(provider);
             }
-            return value.ToString(OutputFormat, FormatProvider ?? CultureInfo.CurrentCulture);
+            return value.ToString(OutputFormat, provider);
         }
     }
 }

FlatFiles/FixedLengthOptions.cs

@@ -88,6 +88,11 @@ public OverflowTruncationPolicy TruncationPolicy
         /// </summary>
         public bool IsColumnContextDisabled { get; set; }
 
+        /// <summary>
+        /// Gets or sets the global, default format provider.
+        /// </summary>
+        public IFormatProvider FormatProvider { get; set; }
+
         /// <summary>
         /// Duplicates the options.
         /// </summary>

FlatFiles/FlatFiles.csproj

@@ -10,10 +10,10 @@
     <RepositoryUrl>https://github.com/jehugaleahsa/FlatFiles.git</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>csv;comma;tab;separated;value;delimited;flat;file;fixed;width;fixed-width;length;fixed-length;parser;parsing;parse</PackageTags>
-    <PackageReleaseNotes>FixedLengthReader not reading records with metadata.</PackageReleaseNotes>
+    <PackageReleaseNotes>Support pre- and post-parsing and formatting operations. Support overriding IFormatProvider globally in IOptions.</PackageReleaseNotes>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>FlatFiles.snk</AssemblyOriginatorKeyFile>
-    <Version>4.3.4</Version>
+    <Version>4.4.0</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net451' ">
@@ -27,8 +27,8 @@
   <PropertyGroup>
     <LangVersion>7.3</LangVersion>
     <PackageIconUrl>https://raw.githubusercontent.com/jehugaleahsa/FlatFiles/master/icon.png</PackageIconUrl>
-    <AssemblyVersion>4.3.4.0</AssemblyVersion>
-    <FileVersion>4.3.4.0</FileVersion>
+    <AssemblyVersion>4.4.0.0</AssemblyVersion>
+    <FileVersion>4.4.0.0</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|netstandard1.6|AnyCPU'">