More of a How-To, than a best practice, but since Pagination with GraphQL resolvers is a bit confusing, here are some things on that:
Using Pagination Arguments in a UDF
Docs can be helpful, even if they get a bad reputation! They have a good example of how to use pagination arguments in a UDF.
I created a helper function that builds on that example:
const paginateWithOptions = (set, size, after, before) =>
q.If(
q.Equals(before, null),
q.If(
q.Equals(after, null),
q.Paginate(set, { size: size }),
q.Paginate(set, { size: size, after: after })
),
q.Paginate(set, { size: size, before: before })
)
Use like this:
{
name: "paginatedResolver",
body: q.Query(
q.Lambda(
['input', 'size', 'after', 'before'],
q.Map(
paginateWithOptions(
q.Call(q.Function('getSomeSet'), q.Var('input')),
q.Var('size'),
q.Var('after'),
q.Var('before')
),
q.Lambda('ref', q.Get(q.Var('ref')))
)
)
)
})
Where getSomeSet UDF returns a Set, for example from Match(Index(...))