Passing paging parameters to a Function

Help
,
1

Hi,

I have an index and I’m using it from within a UDF. I’d like to allow the user to pass size/before/after parameters to the function and to use them inside when calling to the index.

Here’s what I tried, but it doesn’t work:

Query(
  Lambda(
    [
      "paramA",
      "paramB",
      "size",
      "cursorBefore",
      "cursorAfter"
    ],
    Let(
      {
        paging: If(
          Not(IsNull(Var("cursorAfter"))),
          { size: Var("size"), after: Var("cursorAfter") },
          If(
            Not(IsNull(Var("cursorBefore"))),
            { size: Var("size"), before: Var("cursorBefore") },
            { size: Var("size") }
          )
        )
      },
      Map(
        Paginate(
            Match(Index("my_index"), [
              Var("paramA"),
              Var("paramB")
            ])
          ),
          Var("paging") /*couldn't get anything here that works*/
        ),
        Lambda(
          ["ref"],
          Get(Var("ref"))
        )
      )
    )
  )
)

The above definition of paging is very verbose and I got to it after a lot of trial and error that didn’t work. It seems that Paginate only accepts static paging definition.

Any idea?
Thanks!

2

This is right. Though it is unfortunate. There might already be a ticket out to fix that, but I certainly don’t know where it is.

You’ll have to put the Pagination function in each branch of If functions. I like to use a helper function in js to make defining these kind of UDFs easier.

The following is part time of a topic on GraphQl, but this bit is as every bit of relevant for plain FQL.

UPDATE (April 2023): I replied again with a link to an example in documentation of creating a pagination UDF.

3

Hi @ptpaterson, thanks for the quick reply.
I will try that later today

5

There is an example in the docs of how to create a UDF that accepts size, before and after arguments for pagination. This is often required for GraphQL custom resolvers, but the technique is not exclusive to that.