Feature request: add next page and prev page numbers

[Muhammad Arsalan]

Thanks for amazing package.

Pagination should return previous page and next page .

if current page is 1 than previous page should be null
if last page is null the next page should be null

eg:
{
total: number
currentPage: number
perPage: number
prev: number | null
next: number | null
}

it will give flexibility and ease to use for pagination in tables on the front end.

I did add the next and prev page in the code but I cannot pass the tests so I am a little confused. can I submit the PR without tests I am not sure if I can fix those tests

this is how I did

return this.client.transaction(async (trx) => {
     const result = await this.transacting(trx);
     let lastPage = null;
     if (shouldFetchTotals) {
       const countResult = await countQuery.transacting(trx);
       const total = +(countResult.TOTAL || countResult.total || 0);
       lastPage = Math.ceil(total / perPage);
       pagination = {
         total,
         lastPage: lastPage,
       };
     }

     // Add pagination data to paginator object
     pagination = postProcessResponse({
       ...pagination,
       perPage,
       currentPage,
       prev: currentPage  >1 ? currentPage - 1 : null,
       next: currentPage < lastPage ? currentPage + 1 : null,
       from: offset,
       to: offset + result.length,
     });

     return { data: result, pagination };
   });

[Felix Mosheev]

Hi, it is possible to add, but sounds like it is always uses the currentPage, therefore I'm not sure it should part of the lib...

[Muhammad Arsalan]

Thanks for responding

Yes it uses the currentPage for validating the next and previous? What are your concerns about using currentPage within lib. Or do you have any other method?

[Felix Mosheev]

currentPage is part of the lib input, your feature request, is related to manipulating input of the lib, therefore, I don't think that it should be part of the lib.

Moreover, the lib not fetches the total count always (which is an additional query), therefore, lastPage is not always available, so you can't calculate nextPage reliably.

[Muhammad Arsalan]

got your point. we can also make this optional just how the lib handles total query by passing isLengthAware prop. the same can be done here with one additional prop. like hasNextAndPrevPage it may not be best name but it can be discussed.
eg:
.paginate({ perPage: 2, currentPage: 2, isLengthAware: true ,hasNextAndPrevPage:true})

[Felix Mosheev]

I don't want to introduce additional boolean flag for this,
I can add these fields only when last page is available, therefore, only when the query is content aware (isFromStart=true, isLengthAware=true, 1currentPage=1`).

Do you think that it should be added then?

[Muhammad Arsalan]

I think it should be fine with it. thanks.

[Felix Mosheev]

Released in v3.1.0