Drop TableStyle in favor of ITableRenderer (thanks DennieBee 😘)

Author: RobThree

README.md

@@ -363,19 +363,22 @@ Founder Facebook  | Mark Zuckerberg | 1,300,000.00 | 1984-03-14 |            |
 
 The `DefaultObjectHandler`, by default, pads all rows with missing values with `null` values.
 
-## Styles
+## Table Renderers
 
-The TextTableBuilder has support for (very simple) styles. These can be specified as an optional argument to the `Build()` method. Currently only a very few styles are supported.
+The TextTableBuilder uses an `ITableRenderer` to do the actual 'rendering' of the table. The TableRenderer is provided with `RenderColums`, which provide column information, and an `IEnumerable<string[]>` which represents the rows and values. The values have been formatted at this point; the table renderer takes care of aligning, padding etc.
+
+By default, the TextTableBuilder uses the `DefaultTableRenderer` which produced the above examples. Two other, very simple, renderers are provided. These are the `MinimalTableRenderer` and `MSDOSTableRenderer`.
+
+To use a specific `ITableRenderer` you pass one to the `Build()` method:
 
-To specify a style, invoke the `Build()` method with a `style` argument:
 
 ```c#
-Console.WriteLine(tablebuilder.Build(table, TableStyle.MSDOS));
+Console.WriteLine(tablebuilder.Build(table, new MSDOSTableRenderer()));
 ```
 
-Going back to our [very first example](#quickstart), the following styles are currently implemented. More _may_ be added in the future (as well as ANSI color support etc.):
+Going back to our [very first example](#quickstart), the following styles are currently provided. More _may_ be added in the future (as well as ANSI color support etc.) but it's also trivial to build your own; just implement `ITableRenderer`:
 
-### TableStyle.Default
+### DefaultTableRenderer
 
 ```cmd
 No | Name            | Position          |    Salary
@@ -386,7 +389,7 @@ No | Name            | Position          |    Salary
 4  | Mark Zuckerberg | Founder Facebook  | 1,300,000
 ```
 
-### TableStyle.Minimal
+### MinimalTableRenderer
 
 ```cmd
 No Name            Position             Salary
@@ -396,7 +399,7 @@ No Name            Position             Salary
 4  Mark Zuckerberg Founder Facebook  1,300,000
 ```
 
-### TableStyle.MSDOS
+### MSDOSTableRenderer
 
 ```cmd
 No║Name           ║Position         ║   Salary

TextTableBuilder/Column.cs

@@ -4,8 +4,8 @@ namespace TextTableBuilder;
 
 public record Column(
     string Name,
-    Align Align = Column.DefaultAlign,
-    Align RowAlign = Row.DefaultAlign,
+    Align HeaderAlign = Column.DefaultAlign,
+    Align ValueAlign = Row.DefaultAlign,
     int? MinWidth = null,
     int? Width = null,
     ITypeHandler? TypeHandler = null
@@ -50,4 +50,4 @@ private static Align GetAlignFromChar(char align)
             '~' => Align.Center,
             _ => Align.Left
         };
-}
+}

TextTableBuilder/RenderColumn.cs

@@ -0,0 +1,3 @@
+namespace TextTableBuilder;
+
+public record RenderColumn(string Name, int Width, Align HeaderAlign, Align ValueAlign);

TextTableBuilder/TableBuilder.cs

@@ -1,6 +1,6 @@
 using System.Globalization;
-using System.Text;
 using TextTableBuilder.ObjectHandlers;
+using TextTableBuilder.TableRenderers;
 using TextTableBuilder.TypeHandlers;
 
 namespace TextTableBuilder;
@@ -10,21 +10,29 @@ public class TableBuilder
     public TypeHandlerCollection TypeHandlers { get; } = new();
     public ObjectHandlerCollection ObjectHandlers { get; } = new();
 
+    public static readonly ITableRenderer DefaultTableRenderer = new DefaultTableRenderer();
+
     public string Build(Table table)
-        => Build(table, TableStyle.Default);
+        => Build(table, DefaultTableRenderer, CultureInfo.CurrentUICulture);
+
+    public string Build(Table table, ITableRenderer tableRenderer)
+        => Build(table, tableRenderer, CultureInfo.CurrentUICulture);
 
-    public string Build(Table table, TableStyle tableStyle)
-        => Build(table, tableStyle, CultureInfo.CurrentUICulture);
     public string Build(Table table, IFormatProvider formatProvider)
-        => Build(table, TableStyle.Default, formatProvider);
+        => Build(table, DefaultTableRenderer, formatProvider);
 
-    public string Build(Table table, TableStyle tableStyle, IFormatProvider formatProvider)
+    public string Build(Table table, ITableRenderer tableRenderer, IFormatProvider formatProvider)
     {
         if (table is null)
         {
             throw new ArgumentNullException(nameof(table));
         }
 
+        if (tableRenderer is null)
+        {
+            throw new ArgumentNullException(nameof(tableRenderer));
+        }
+
         if (formatProvider is null)
         {
             throw new ArgumentNullException(nameof(formatProvider));
@@ -66,44 +74,9 @@ public string Build(Table table, TableStyle tableStyle, IFormatProvider formatPr
         colwidths = cols.Select((w, i) => Math.Min(w.Width ?? int.MaxValue, colwidths[i])).ToArray();
 
         // Now build actual table
-        var sb = new StringBuilder();
-
-        // Headers
-        sb.AppendLine(MakeRow(tableStyle, table.Columns.Select((col, i) => MakeCell(col.Name, col.Align, colwidths[i], tableStyle.Padding))));
-
-        // Header separator
-        if (tableStyle.HeaderSeparator is not null)
-        {
-            sb.AppendLine(MakeRow(tableStyle, colwidths.Select(w => new string(tableStyle.HeaderSeparator.Value, w))));
-        }
-
-        // Rows
-        foreach (var row in rows)
-        {
-            sb.AppendLine(MakeRow(tableStyle, row.Select((value, i) => MakeCell(value, cols[i].RowAlign, colwidths[i], tableStyle.Padding))));
-        }
-        return sb.ToString();
+        return tableRenderer.Render(
+            Array.AsReadOnly(table.Columns.Select((c, i) => new RenderColumn(c.Name, colwidths[i], c.HeaderAlign, c.ValueAlign)).ToArray()),
+            rows
+        );
     }
-
-    private static string MakeRow(TableStyle tableStyle, IEnumerable<string> values)
-        => string.Join(tableStyle.ColumnSeparator, values);
-
-    private static string MakeCell(string value, Align align, int width, char paddingChar)
-        => AlignString(TruncateString(value, align, width), align, width, paddingChar);
-
-    private static string AlignString(string value, Align align, int width, char paddingChar)
-        => align switch
-        {
-            Align.Right => value.PadLeft(width, paddingChar),
-            Align.Center => value.PadLeft((width - value.Length) / 2 + value.Length, paddingChar).PadRight(width, paddingChar),
-            _ => value.PadRight(width, paddingChar)
-        };
-
-    private static string TruncateString(string value, Align align, int length)
-        => align switch
-        {
-            Align.Right => value.Substring(Math.Max(value.Length - length, 0), Math.Min(value.Length, length)),
-            Align.Center => value.Substring(Math.Max((value.Length - length) / 2, 0), Math.Min(length, value.Length)),
-            _ => value.Substring(0, Math.Min(length, value.Length))
-        };
 }

TextTableBuilder/TableRenderers/BaseTableRenderer.cs

@@ -0,0 +1,30 @@
+using System.Collections.ObjectModel;
+
+namespace TextTableBuilder.TableRenderers;
+
+public abstract class BaseTableRenderer : ITableRenderer
+{
+    public abstract string Render(ReadOnlyCollection<RenderColumn> columns, IEnumerable<string[]> rows);
+
+    protected static string RenderRow(string columnSeparator, IEnumerable<string> values)
+        => string.Join(columnSeparator, values);
+
+    protected static string RenderCell(string value, Align align, int width, char paddingChar)
+        => AlignString(TruncateString(value, align, width), align, width, paddingChar);
+
+    protected static string AlignString(string value, Align align, int width, char paddingChar)
+        => align switch
+        {
+            Align.Right => value.PadLeft(width, paddingChar),
+            Align.Center => value.PadLeft((width - value.Length) / 2 + value.Length, paddingChar).PadRight(width, paddingChar),
+            _ => value.PadRight(width, paddingChar)
+        };
+
+    protected static string TruncateString(string value, Align align, int length)
+        => align switch
+        {
+            Align.Right => value.Substring(Math.Max(value.Length - length, 0), Math.Min(value.Length, length)),
+            Align.Center => value.Substring(Math.Max((value.Length - length) / 2, 0), Math.Min(length, value.Length)),
+            _ => value.Substring(0, Math.Min(length, value.Length))
+        };
+}

TextTableBuilder/TableRenderers/DefaultTableRenderer.cs

@@ -0,0 +1,6 @@
+namespace TextTableBuilder.TableRenderers;
+
+public class DefaultTableRenderer : SimpleTableRenderer
+{
+    public DefaultTableRenderer() : base(' ', " | ", '-') { }
+}

TextTableBuilder/TableRenderers/ITableRenderer.cs

@@ -0,0 +1,8 @@
+using System.Collections.ObjectModel;
+
+namespace TextTableBuilder.TableRenderers;
+
+public interface ITableRenderer
+{
+    string Render(ReadOnlyCollection<RenderColumn> columns, IEnumerable<string[]> rows);
+}

TextTableBuilder/TableRenderers/MSDOSTableRenderer.cs

@@ -0,0 +1,6 @@
+namespace TextTableBuilder.TableRenderers;
+
+public class MSDOSTableRenderer : SimpleTableRenderer
+{
+    public MSDOSTableRenderer() : base(' ', "║", '═') { }
+}

TextTableBuilder/TableRenderers/MinimalTableRenderer.cs

@@ -0,0 +1,6 @@
+namespace TextTableBuilder.TableRenderers;
+
+public class MinimalTableRenderer : SimpleTableRenderer
+{
+    public MinimalTableRenderer() : base(' ', " ", null) { }
+}

TextTableBuilder/TableRenderers/SimpleTableRenderer.cs

@@ -0,0 +1,39 @@
+using System.Collections.ObjectModel;
+using System.Text;
+
+namespace TextTableBuilder.TableRenderers;
+
+public abstract class SimpleTableRenderer : BaseTableRenderer
+{
+    private readonly char _paddingchar;
+    private readonly string _columnseparator;
+    private readonly char? _rowseparator;
+
+    public SimpleTableRenderer(char paddingChar, string columnSeparator, char? rowSeparator)
+    {
+        _paddingchar = paddingChar;
+        _columnseparator = columnSeparator;
+        _rowseparator = rowSeparator;
+    }
+
+    public override string Render(ReadOnlyCollection<RenderColumn> columns, IEnumerable<string[]> rows)
+    {
+        var sb = new StringBuilder();
+
+        // Headers
+        sb.AppendLine(RenderRow(_columnseparator, columns.Select(c => RenderCell(c.Name, c.HeaderAlign, c.Width, _paddingchar))));
+
+        // Header separator
+        if (_rowseparator is not null)
+        {
+            sb.AppendLine(RenderRow(_columnseparator, columns.Select(c => new string(_rowseparator.Value, c.Width))));
+        }
+
+        // Rows
+        foreach (var row in rows)
+        {
+            sb.AppendLine(RenderRow(_columnseparator, row.Select((value, i) => RenderCell(value, columns[i].ValueAlign, columns[i].Width, _paddingchar))));
+        }
+        return sb.ToString();
+    }
+}