/// <summary>
/// Creates the constructor arguments used to create a type.
/// </summary>
/// <param name="map">The mapping to create the arguments for.</param>
/// <param name="argumentExpressions">The arguments that will be added to the mapping.</param>
protected virtual void CreateConstructorArgumentExpressionsForMapping(ClassMap map, List <Expression> argumentExpressions)
{
foreach (var parameterMap in map.ParameterMaps)
{
if (parameterMap.ConstructorTypeMap != null)
{
// Constructor paramter type.
var arguments = new List <Expression>();
CreateConstructorArgumentExpressionsForMapping(parameterMap.ConstructorTypeMap, arguments);
var constructorExpression = Expression.New(Reader.Configuration.GetConstructor(parameterMap.ConstructorTypeMap.ClassType), arguments);
argumentExpressions.Add(constructorExpression);
}
else if (parameterMap.ReferenceMap != null)
{
// Reference type.
var referenceAssignments = new List <MemberAssignment>();
ExpressionManager.CreateMemberAssignmentsForMapping(parameterMap.ReferenceMap.Data.Mapping, referenceAssignments);
var referenceBody = ExpressionManager.CreateInstanceAndAssignMembers(parameterMap.ReferenceMap.Data.Parameter.ParameterType, referenceAssignments);
argumentExpressions.Add(referenceBody);
}
else
{
// Value type.
var index = Reader.Configuration.HasHeaderRecord
? Reader.GetFieldIndex(parameterMap.Data.Name, 0)
: parameterMap.Data.Index;
// Get the field using the field index.
var method = typeof(IReaderRow).GetProperty("Item", typeof(string), new[] { typeof(int) }).GetGetMethod();
Expression fieldExpression = Expression.Call(Expression.Constant(Reader), method, Expression.Constant(index, typeof(int)));
// Convert the field.
var typeConverterExpression = Expression.Constant(parameterMap.Data.TypeConverter);
parameterMap.Data.TypeConverterOptions = TypeConverterOptions.Merge(new TypeConverterOptions {
CultureInfo = Reader.Context.ReaderConfiguration.CultureInfo
}, Reader.Context.ReaderConfiguration.TypeConverterOptionsCache.GetOptions(parameterMap.Data.Parameter.ParameterType), parameterMap.Data.TypeConverterOptions);
// Create type converter expression.
var memberMapData = new MemberMapData(null)
{
Index = parameterMap.Data.Index,
TypeConverter = parameterMap.Data.TypeConverter,
TypeConverterOptions = parameterMap.Data.TypeConverterOptions
};
memberMapData.Names.Add(parameterMap.Data.Name);
Expression typeConverterFieldExpression = Expression.Call(typeConverterExpression, nameof(ITypeConverter.ConvertFromString), null, fieldExpression, Expression.Constant(Reader), Expression.Constant(memberMapData));
typeConverterFieldExpression = Expression.Convert(typeConverterFieldExpression, parameterMap.Data.Parameter.ParameterType);
fieldExpression = typeConverterFieldExpression;
argumentExpressions.Add(fieldExpression);
}
}
}
/// <summary>
/// Creates the action delegate used to hydrate a record's members with data from the reader.
/// </summary>
/// <typeparam name="T">The record type.</typeparam>
protected virtual Action <T> CreateHydrateRecordAction <T>()
{
var recordType = typeof(T);
if (reader.Context.ReaderConfiguration.Maps[recordType] == null)
{
reader.Context.ReaderConfiguration.Maps.Add(reader.Context.ReaderConfiguration.AutoMap(recordType));
}
var mapping = reader.Context.ReaderConfiguration.Maps[recordType];
var recordTypeParameter = Expression.Parameter(recordType, "record");
var memberAssignments = new List <Expression>();
foreach (var memberMap in mapping.MemberMaps)
{
var fieldExpression = expressionManager.CreateGetFieldExpression(memberMap);
if (fieldExpression == null)
{
continue;
}
var memberTypeParameter = Expression.Parameter(memberMap.Data.Member.MemberType(), "member");
var memberAccess = Expression.MakeMemberAccess(recordTypeParameter, memberMap.Data.Member);
var memberAssignment = Expression.Assign(memberAccess, fieldExpression);
memberAssignments.Add(memberAssignment);
}
foreach (var referenceMap in mapping.ReferenceMaps)
{
if (!reader.CanRead(referenceMap))
{
continue;
}
var referenceAssignments = new List <MemberAssignment>();
expressionManager.CreateMemberAssignmentsForMapping(referenceMap.Data.Mapping, referenceAssignments);
var referenceBody = expressionManager.CreateInstanceAndAssignMembers(referenceMap.Data.Member.MemberType(), referenceAssignments);
var memberTypeParameter = Expression.Parameter(referenceMap.Data.Member.MemberType(), "referenceMember");
var memberAccess = Expression.MakeMemberAccess(recordTypeParameter, referenceMap.Data.Member);
var memberAssignment = Expression.Assign(memberAccess, referenceBody);
memberAssignments.Add(memberAssignment);
}
var body = Expression.Block(memberAssignments);
return(Expression.Lambda <Action <T> >(body, recordTypeParameter).Compile());
}
/// <summary>
/// Creates a <see cref="Delegate"/> of type <see cref="Func{T}"/>
/// that will create a record of the given type using the current
/// reader row.
/// </summary>
/// <param name="recordType">The record type.</param>
protected override Delegate CreateCreateRecordDelegate(Type recordType)
{
if (Reader.Context.Maps[recordType] == null)
{
Reader.Context.Maps.Add(Reader.Context.AutoMap(recordType));
}
var map = Reader.Context.Maps[recordType];
Expression body;
if (map.ParameterMaps.Count > 0)
{
// This is a constructor parameter type.
var arguments = new List <Expression>();
ExpressionManager.CreateConstructorArgumentExpressionsForMapping(map, arguments);
var args = new GetConstructorArgs
{
ClassType = map.ClassType
};
body = Expression.New(Reader.Configuration.GetConstructor(args), arguments);
}
else
{
var assignments = new List <MemberAssignment>();
ExpressionManager.CreateMemberAssignmentsForMapping(map, assignments);
if (assignments.Count == 0)
{
throw new ReaderException(Reader.Context, $"No members are mapped for type '{recordType.FullName}'.");
}
body = ExpressionManager.CreateInstanceAndAssignMembers(recordType, assignments);
}
var funcType = typeof(Func <>).MakeGenericType(recordType);
return(Expression.Lambda(funcType, body).Compile());
}
