/// <summary>
/// Register a manual mapping information from source to target
/// </summary>
/// <typeparam name="TSource">Source type</typeparam>
/// <typeparam name="TTarget">Target type</typeparam>
public void RegisterMap <TSource, TTarget>(Action <TSource, TTarget> convert)
{
var sourceType = typeof(TSource);
var targetType = typeof(TTarget);
if (!_mappings.ContainsKey(sourceType))
{
_mappings[sourceType] = new Dictionary <Type, ILMappingInfo>();
}
ILMappingInfo ilMappingInfo = _mappings[sourceType].ContainsKey(targetType)
? _mappings[sourceType][targetType]
: new IlMappingInfo <TSource, TTarget>();
ilMappingInfo.ManualMapper = (s, t) => convert((TSource)s, (TTarget)t);
ilMappingInfo.InstanceMapper = (s, t) => convert((TSource)s, (TTarget)t);
_mappings[sourceType][targetType] = ilMappingInfo;
}
/// <summary>
/// Generate dynamic method for collection mapping
/// </summary>
Func <ILMappingInfo, IList <TSource>, TTarget[]> GenerateCollectionDelegate <TSource, TTarget>(List <PropertyMapper> properties, ILMappingInfo ilMappingInfo)
{
var sourceType = typeof(TSource);
var targetType = typeof(TTarget);
var targetCollectionType = typeof(TTarget[]);
var targetConstrucotr = targetType.GetConstructor(Type.EmptyTypes);
if (targetConstrucotr == null)
{
throw new ArgumentException("Target type must have a parameterless constructor");
}
var targetCollectionConstrucotr = targetCollectionType.GetConstructor(new[] { typeof(int) });
if (targetCollectionConstrucotr == null)
{
throw new ArgumentException();
}
var dm = new DynamicMethod($"_MAP_LIST_{sourceType.Name}_{targetType.Name}",
typeof(TTarget[]),
new[] { typeof(ILMappingInfo), typeof(IList <TSource>) },
typeof(TTarget).GetTypeInfo().Module);
var il = dm.GetILGenerator();
var loopStart = il.DefineLabel();
var loopExit = il.DefineLabel();
// Store argument list in local
var mappingInfoLocal = il.DeclareLocal(typeof(ILMappingInfo));
var source = il.DeclareLocal(typeof(IList <TSource>));
var result = il.DeclareLocal(typeof(TTarget[]));
var count = il.DeclareLocal(typeof(IList <TSource>));
var index = il.DeclareLocal(typeof(IList <TSource>));
var sourceItem = il.DeclareLocal(typeof(TSource));
var targetItem = il.DeclareLocal(typeof(TTarget));
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Stloc, mappingInfoLocal);
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Stloc, source);
// Define result array
;
il.Emit(OpCodes.Ldloc, source);
il.Emit(OpCodes.Call, typeof(ICollection).GetMethod("get_Count"));
il.Emit(OpCodes.Stloc, count);
il.Emit(OpCodes.Ldloc, count);
il.Emit(OpCodes.Newarr, typeof(TTarget));
il.Emit(OpCodes.Stloc, result);
il.Emit(OpCodes.Ldc_I4_0);
il.Emit(OpCodes.Stloc, index);
// Mark loop start
il.MarkLabel(loopStart);
//Get item at index
il.Emit(OpCodes.Ldloc, source);
il.Emit(OpCodes.Ldloc, index);
il.Emit(OpCodes.Call, typeof(IList <TSource>).GetMethod("get_Item"));
il.Emit(OpCodes.Stloc, sourceItem);
// Create new item
il.Emit(OpCodes.Newobj, targetConstrucotr);
il.Emit(OpCodes.Stloc, targetItem);
// Map properties
foreach (var property in properties)
{
EmitPropertyMap(property, il, sourceItem, targetItem);
}
if (ilMappingInfo.AdditionalMap != null)
{
var method = ilMappingInfo.GetType().GetMethod(nameof(ILMappingInfo.ExecuteAdditionalMap));
if (method != null)
{
il.Emit(OpCodes.Ldloc, mappingInfoLocal);
il.Emit(OpCodes.Ldloc, sourceItem);
il.Emit(OpCodes.Ldloc, targetItem);
il.Emit(OpCodes.Call, method);
}
}
// Add item to list
il.Emit(OpCodes.Ldloc, result);
il.Emit(OpCodes.Ldloc, index);
il.Emit(OpCodes.Ldloc, targetItem);
il.Emit(OpCodes.Stelem_Ref);
// increment index
il.Emit(OpCodes.Ldloc, index);
il.Emit(OpCodes.Ldc_I4_1);
il.Emit(OpCodes.Add);
il.Emit(OpCodes.Stloc, index);
// Check loop end
il.Emit(OpCodes.Ldloc, index);
il.Emit(OpCodes.Ldloc, count);
il.Emit(OpCodes.Beq, loopExit);
// Repeat
il.Emit(OpCodes.Br, loopStart);
il.MarkLabel(loopExit);
il.Emit(OpCodes.Ldloc, result);
il.Emit(OpCodes.Ret);
return((Func <ILMappingInfo, IList <TSource>, TTarget[]>)dm.CreateDelegate(typeof(Func <ILMappingInfo, IList <TSource>, TTarget[]>)));
}
