[Question] If I needed to return total count for pagination, where is the best place to implement?

[davidhenley]

If I am using pagination to skip and take based on page size, but still need to return total items to the client, where should I implement this?

I want to run count after the where filter so I get the actual count of items returned from the search but before my pagination.

In the specification? or run Count() on the entire table first then use the specification?

Do I need a filter specification, and then another pagination specification?

        public GetCustomersForListSpecification(QueryParams query)
        {
            if (!string.IsNullOrWhiteSpace(query.Filter))
                Query.Where(x => x.Name.Contains(query.Filter));

           **********
           NEED TO CALCULATE TOTAL COUNT HERE BEFORE PAGINATION
           **********

            Query
                .Select(x => new CustomerForListResponse
                {
                    Id = x.Id,
                    Name = x.Name
                })
                .Skip((query.Page - 1) * query.PerPage)
                .Take(query.PerPage);
        }

I was using this on the IQueryable:

var source = _context.Customers.Where(x => x.Name.Contains(query.Filter));
var count = await source.CountAsync();
var items = await source.Skip((query.Page - 1) * query.PerPage).Take(query.PerPage).ToListAsync();

Is this a job for an evaluator? I'm trying to find documentation on this

[davidhenley]

Duplicate #134

[davidhenley]

EDIT: Can we add this to docs? A simple example would be fine for best practices?

Thank you for this amazing package! It will slim my code down a lot.

[fiseni]

Here is the issue #135. I tried to elaborate it, we'll need to add it to the docs.

[davidhenley]

Thanks @fiseni I’m playing with it now.

I just came upon this package and trying to grok it.

Are the 2 YouTube videos currently the best way to learn more about extending the specs and evaluators?

[fiseni]

Not really to be honest. Perhaps we need to create a new video, a planned one :) We recorded the last ones on the fly with no particular agenda.

I know we're lacking good docs. We started working on it, but we're far from finished.
https://ardalis.github.io/Specification/

[davidhenley]

OK, thank you! Once I understand everything going on I'll see if I can create some PR's!

[ardalis]

If you want to add/update anything in the docs, they're just markdown files here:
https://github.com/ardalis/Specification/tree/main/docs

Thanks!

[tnlthanzeel]

hi all. im having a scenario where i start the specification from the aggregate root and include children with skip and take. it works fine. but how can i get the totalrecord count of the children using this library?