internal static IQueryable <TEntity> Paged <TEntity>(this IQueryable <TEntity> source, int itemId, bool isPrev, int count = 0)
where TEntity : class, IListItemEntity, new()
{
Check.NotNull(source, nameof(source));
if (source is SpEntityQueryable <TEntity, ISpEntryDataContext> )
{
var executor = (source as SpEntityQueryable <TEntity, ISpEntryDataContext>).GetExecutor();
if (executor != null)
{
var args = (SpQueryArgs <ISpEntryDataContext>)executor.SpQueryArgs.Clone();
var lastItem = itemId > 0 ? source.Where(item => item.Id == itemId).FirstListItem() : null;
if (lastItem != null)
{
args.IsPaged = true;
args.IsPagedPrev = isPrev;
var expression = new PagedExpression <ISpEntryDataContext>(source.Expression, args, lastItem, false);
var provider = new SpEntityQueryable <TEntity>(args).Provider;
source = new SpEntityQueryable <TEntity>(provider, source.Expression).Concat(new SpEntityQueryable <TEntity>(provider, expression));
if (count > 0)
{
source = source.Take(count);
}
}
else
{
source = Enumerable.Empty <TEntity>().AsQueryable();
}
}
}
return(source);
}
public static IQueryable <TEntity> Previous <TEntity>(this IQueryable <TEntity> source, int count = 0)
where TEntity : class, IListItemEntity, new()
{
Check.NotNull(source, nameof(source));
if (source is SpEntityQueryable <TEntity, ISpEntryDataContext> )
{
var executor = (source as SpEntityQueryable <TEntity, ISpEntryDataContext>).GetExecutor();
if (executor != null)
{
var args = (SpQueryArgs <ISpEntryDataContext>)executor.SpQueryArgs.Clone();
var firstItem = args.IsPaged && args.IsPagedPrev ? source.ToListItems().FirstOrDefault() : source.FirstListItem();
if (firstItem != null)
{
args.IsPaged = true;
args.IsPagedPrev = true;
var expression = new PagedExpression <ISpEntryDataContext>(source.Expression, args, firstItem, true);
var provider = new SpEntityQueryable <TEntity>(args).Provider;
source = new SpEntityQueryable <TEntity>(provider, source.Expression).Concat(new SpEntityQueryable <TEntity>(provider, expression));
if (count > 0)
{
source = source.Take(count);
}
}
}
}
return(source);
}
public virtual void VisitPagedClause(PagedExpression <TContext /*, TEntity*/> expression, QueryModel queryModel)
{
if (_args != null && _spView != null)
{
var visitor = new PagedExpressionVisitor <TContext, TEntity>(_args, expression, _spView);
visitor.VisitQueryModel(queryModel);
_args.PagingInfo = visitor.PagingInfo;
_args.IsPaged = true;
}
}
public PagedExpressionVisitor(SpQueryArgs <TContext> args, PagedExpression <TContext /*, TEntity*/> expression, Caml.View spView) : base(args, null)
{
_args = args;
_expression = expression;
_spView = spView;
}