easier to use constructors for complex mappings

Author: giometrix

src/TableStorage.Abstractions.POCO.Tests/PocoTableStoreTests.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Linq.Expressions;
+using Microsoft.WindowsAzure.Storage.Table;
+using TableStorage.Abstractions.TableEntityConverters;
+
+namespace TableStorage.Abstractions.POCO
+{
+	public class CalculatedKeysTableConverter<T, TPartitionKey, TRowKey> : ITableConverter<T, TPartitionKey, TRowKey>
+		where T: new()
+	{
+		private readonly KeyMapper<T, TPartitionKey> _partitionMapper;
+		private readonly KeyMapper<T, TRowKey> _rowMapper;
+		private readonly Expression<Func<T, object>>[] _ignoredProperties;
+
+		public CalculatedKeysTableConverter(KeyMapper<T, TPartitionKey> partitionMapper, KeyMapper<T,TRowKey> rowMapper, 
+			params Expression<Func<T, object>>[] ignoredProperties)
+		{
+			_partitionMapper = partitionMapper;
+			_rowMapper = rowMapper;
+			_ignoredProperties = ignoredProperties;
+		}
+		public DynamicTableEntity ToEntity(T obj)
+		{
+			return obj.ToTableEntity(_partitionMapper.ToKey(obj), _rowMapper.ToKey(obj), _ignoredProperties);
+		}
+
+		public T FromEntity(DynamicTableEntity entity)
+		{
+			return entity.FromTableEntity(_partitionMapper.KeyProperty, _partitionMapper.FromKey, _rowMapper.KeyProperty,
+				_rowMapper.FromKey);
+		}
+
+		public string PartitionKey(TPartitionKey key)
+		{
+			return _partitionMapper.ToKeyFromParameter(key);
+		}
+
+		public string RowKey(TRowKey key)
+		{
+			return _rowMapper.ToKeyFromParameter(key);
+		}
+	}
+}

src/TableStorage.Abstractions.POCO/CalculatedKeysTableConverter.cs

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+using System;
+
+namespace TableStorage.Abstractions.POCO
+{
+	public class FixedKeyMapper<T, TKey> : KeyMapper<T, TKey>
+	{
+		public FixedKeyMapper(string key) : base(x=>key, null, null, x=>key)
+		{
+		}
+	}
+}

src/TableStorage.Abstractions.POCO/FixedKeyMapper.cs

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+using Microsoft.WindowsAzure.Storage.Table;
+
+namespace TableStorage.Abstractions.POCO
+{
+	public interface ITableConverter<T, TPartitionKey, TRowKey> 
+	{
+		DynamicTableEntity ToEntity(T obj);
+		T FromEntity(DynamicTableEntity entity);
+		string PartitionKey(TPartitionKey key);
+		string RowKey(TRowKey key);
+	}
+}

src/TableStorage.Abstractions.POCO/ITableConverter.cs

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+using System;
+using System.Linq.Expressions;
+
+namespace TableStorage.Abstractions.POCO
+{
+	public class KeyMapper<T, TKey>
+	{
+		private Func<T, string> _toKey;
+		private Func<TKey, string> _toKeyFromParameter;
+		private Func<string, TKey> _fromKey;
+		private Expression<Func<T, object>> _keyProperty;
+		public KeyMapper(Func<T, string> toKey, Func<string, TKey> fromKey, Expression<Func<T, object>> keyProperty, Func<TKey, string> toKeyFromParameter)
+		{
+			if (toKey == null) throw new ArgumentNullException(nameof(toKey));
+			//if (fromKey == null) throw new ArgumentNullException(nameof(fromKey));
+	
+			this._toKey = toKey;
+			_fromKey = fromKey;
+			_keyProperty = keyProperty;
+			_toKeyFromParameter = toKeyFromParameter;
+		}
+
+		public Expression<Func<T, object>> KeyProperty
+		{
+			get { return _keyProperty; }
+		}
+
+		public string ToKey(T obj)
+		{
+			return _toKey(obj);
+		}
+
+		public string ToKeyFromParameter(TKey key)
+		{
+			return _toKeyFromParameter(key);
+		}
+
+		public TKey FromKey(string key)
+		{
+			return _fromKey(key);
+		}
+	}
+}