public static ObjectInitLambda ParseNewExpression <Tin, Tout>(Expression <Func <Tin, Tout> > newExpression, Tin input = null)
where Tin : class where Tout : class
{
var body = newExpression.Body as NewExpression;
if (body == null)
{
throw new ArgumentException("Expression must be a new anonymous initialiazer");
}
var r = new List <InitMemberAssignment>();
var i = 0;
foreach (var member in body.Members)
{
var argumentExpression = body.Arguments[i++];
var inputParameter = argumentExpression.GetFirstParameterOfType <Tin>();
var lambda = Expression.Lambda(argumentExpression, newExpression.Parameters);
var initMemberAssignment = new InitMemberAssignment
{
Property = member as PropertyInfo,
ValueExpression = argumentExpression,
ValueLambdaExpression = lambda,
};
if (argumentExpression.NodeType == ExpressionType.Constant && argumentExpression is ConstantExpression constantExpression)
{
initMemberAssignment.Type = InitMemberAssignmentType.Constant;
initMemberAssignment.ConstantValue = constantExpression.Value;
}
else if (argumentExpression.NodeType == ExpressionType.MemberAccess &&
argumentExpression is MemberExpression memberExpression &&
memberExpression.Expression == inputParameter)
{
initMemberAssignment.MappedProperty = memberExpression.Member as PropertyInfo;
initMemberAssignment.Type = InitMemberAssignmentType.Property;
}
if (input != null && initMemberAssignment.Type != InitMemberAssignmentType.Constant)
{
initMemberAssignment.EffectiveValue = initMemberAssignment.CompiledLambdaExpression.DynamicInvoke(input);
}
r.Add(initMemberAssignment);
}
return(new ObjectInitLambda(newExpression, r));
}
private static List <InitMemberAssignment> ParseInitExpressionInternal <Tin, Tout>(Expression <Func <Tin, Tout> > initExpression, Tin input = null)
where Tin : class where Tout : class
{
var memberInitExpression = GetBody(initExpression);
var inputParameter = initExpression.Parameters.First();
var r = new List <InitMemberAssignment>();
foreach (MemberBinding binding in memberInitExpression.Bindings)
{
if (!(binding is MemberAssignment memberAssignment))
{
throw new ArgumentException("The init expression MemberBinding must only by type MemberAssignment.");
}
var valueExpression = memberAssignment.Expression;
var lambda = Expression.Lambda(valueExpression, inputParameter);
var initMemberAssignment = new InitMemberAssignment
{
Property = binding.Member as PropertyInfo,
ValueExpression = valueExpression,
ValueLambdaExpression = lambda,
};
if (valueExpression.NodeType == ExpressionType.Constant && valueExpression is ConstantExpression constantExpression)
{
initMemberAssignment.Type = InitMemberAssignmentType.Constant;
initMemberAssignment.ConstantValue = constantExpression.Value;
}
else if (valueExpression.NodeType == ExpressionType.MemberAccess &&
valueExpression is MemberExpression memberExpression &&
memberExpression.Expression == inputParameter)
{
initMemberAssignment.MappedProperty = memberExpression.Member as PropertyInfo;
initMemberAssignment.Type = InitMemberAssignmentType.Property;
}
if (input != null && initMemberAssignment.Type != InitMemberAssignmentType.Constant)
{
initMemberAssignment.EffectiveValue = initMemberAssignment.CompiledLambdaExpression.DynamicInvoke(input);
}
r.Add(initMemberAssignment);
}
return(r);
}
private static List <InitMemberAssignment> ParseInitExpression <T>(MemberInitExpression memberInitExpression)
where T : class
{
var r = new List <InitMemberAssignment>();
foreach (MemberBinding binding in memberInitExpression.Bindings)
{
if (!(binding is MemberAssignment memberAssignment))
{
throw new ArgumentException("The init expression MemberBinding must only by type MemberAssignment.", "memberInitExpression");
}
var valueExpression = memberAssignment.Expression;
var lambda = Expression.Lambda(valueExpression);
var initMemberAssignment = new InitMemberAssignment
{
Property = binding.Member as PropertyInfo,
ValueExpression = valueExpression,
ValueLambdaExpression = lambda,
};
if (valueExpression.NodeType == ExpressionType.Constant && valueExpression is ConstantExpression constantExpression)
{
initMemberAssignment.Type = InitMemberAssignmentType.Constant;
initMemberAssignment.ConstantValue = constantExpression.Value;
initMemberAssignment.EffectiveValue = initMemberAssignment.ConstantValue;
}
else
{
initMemberAssignment.EffectiveValue = initMemberAssignment.CompiledLambdaExpression.DynamicInvoke();
}
r.Add(initMemberAssignment);
}
return(r);
}
