public async Task <QueryResult <T> > GetQueryResultAsync <T>(PostQuery queryObj, Expression <Func <Post, T> > exp)
{
queryObj.NotNull();
exp.NotNull();
var result = new QueryResult <T>();
var query = _context.Posts
.Include(p => p.Category)
.Include(p => p.Tags)
.ThenInclude(pt => pt.Tag)
.AsQueryable();
query = query
.ApplyFiltering(queryObj)
.ApplySearching(queryObj);
result.TotalItems = await query.CountAsync();
query = query
.ApplyOrdering(queryObj)
.ApplyPaging(queryObj);
result.Items = await query
.Select(exp)
.ToListAsync();
return(result);
}
public static IQueryable <Post> ApplyFiltering(this IQueryable <Post> query, PostQuery queryObj)
{
query.NotNull();
queryObj.NotNull();
if (queryObj.CategoryId.HasValue)
{
query = query.Where(p => p.CategoryId == queryObj.CategoryId.Value);
}
if (queryObj.TagId.HasValue)
{
query = query.Where(p => p.Tags.Any(pt => pt.TagId == queryObj.TagId.Value));
}
return(query);
}