// This magic is courtesy of this StackOverflow post.
// https://stackoverflow.com/questions/38316519/replace-parameter-type-in-lambda-expression
// I made some tweaks to adapt it to our needs - @haacked
public static Expression <Func <TTarget, bool> > Convert <TSource, TTarget>(
this Expression <Func <TSource, bool> > root)
{
var visitor = new ParameterTypeVisitor <TSource, TTarget>();
return((Expression <Func <TTarget, bool> >)visitor.Visit(root));
}
public static Func <TTarget, TConst> Convert <TSource, TTarget, TConst>(Expression <Func <TSource, TConst> > root)
{
var visitor = new ParameterTypeVisitor <TSource, TTarget>();
var expression = (Expression <Func <TTarget, TConst> >)visitor.Visit(root);
return(expression?.Compile());
}
public IEnumerable <DalLot> GetByPredicateMany(Expression <Func <DalLot, bool> > expression)
{
var visitor = new ParameterTypeVisitor <DalLot, Lot>(expression);
var expr = visitor.Convert();
var lots = _dbContext.Set <Lot>().Where(expr);
return(lots.Select(lot => new DalLot()
{
Id = lot.LotId,
IsBlocked = lot.IsBlocked,
CategoryName = lot.Category.CategoryName,
CategoryRefId = lot.CategoryRefId,
IsConfirm = lot.IsConfirm,
Discription = lot.Discription,
BlockReason = lot.BlockReason,
LotName = lot.LotName,
SellerRefId = lot.SellerRefId,
EndDate = lot.EndDate,
IsSold = lot.IsSold,
SellerEmail = lot.Seller.Email,
SellerLogin = lot.Seller.Login,
StartDate = lot.StartDate,
StartingBid = lot.StartingBid
}));
}
public DalCategory GetByPredicate(Expression<Func<DalCategory, bool>> expression)
{
var visitor = new ParameterTypeVisitor<DalCategory, Category>(expression);
var expr = visitor.Convert();
var category = _dbContext.Set<Category>().FirstOrDefault(expr);
var dalCategory = category?.ToDalCategory();
return dalCategory;
}
public DalCategory GetByPredicate(Expression <Func <DalCategory, bool> > expression)
{
var visitor = new ParameterTypeVisitor <DalCategory, Category>(expression);
var expr = visitor.Convert();
var category = _dbContext.Set <Category>().FirstOrDefault(expr);
var dalCategory = category?.ToDalCategory();
return(dalCategory);
}
public DalUser GetByPredicate(Expression<Func<DalUser, bool>> expression)
{
var visitor = new ParameterTypeVisitor<DalUser, User>(expression);
var expr = visitor.Convert();
var user = _dbContext.Set<User>().FirstOrDefault(expr);
var dalUser = user?.ToDalUser();
if (dalUser == null)
{
return null;
}
dalUser.Roles = _roleRepository.GetRolesByUserId(user.UserId);
return dalUser;
}
public DalUser GetByPredicate(Expression <Func <DalUser, bool> > expression)
{
var visitor = new ParameterTypeVisitor <DalUser, User>(expression);
var expr = visitor.Convert();
var user = _dbContext.Set <User>().FirstOrDefault(expr);
var dalUser = user?.ToDalUser();
if (dalUser == null)
{
return(null);
}
dalUser.Roles = _roleRepository.GetRolesByUserId(user.UserId);
return(dalUser);
}
public IEnumerable<DalLot> GetByPredicateMany(Expression<Func<DalLot, bool>> expression)
{
var visitor = new ParameterTypeVisitor<DalLot, Lot>(expression);
var expr = visitor.Convert();
var lots = _dbContext.Set<Lot>().Where(expr);
return lots.Select(lot => new DalLot()
{
Id = lot.LotId,
IsBlocked = lot.IsBlocked,
CategoryName = lot.Category.CategoryName,
CategoryRefId = lot.CategoryRefId,
IsConfirm = lot.IsConfirm,
Discription = lot.Discription,
BlockReason = lot.BlockReason,
LotName = lot.LotName,
SellerRefId = lot.SellerRefId,
EndDate = lot.EndDate,
IsSold = lot.IsSold,
SellerEmail = lot.Seller.Email,
SellerLogin = lot.Seller.Login,
StartDate = lot.StartDate,
StartingBid = lot.StartingBid
});
}
