I created a library (only on GitHub for now) to support keyset pagination with absinthe_relay. It’s basically a drop-in replacement in your resolver. An example of paginating a usersConnection:

# in your resolver function
AbsintheRelayKeysetConnection.from_query(
  ecto_users_query,
  &MyRepo.all/1,
  # these args would come from the API user
  %{
    sorts: [%{name: :desc}, %{id: :desc}],
    first: 10,
    after: "0QTwn5SRWyJNbyIsMjZd"
  },
  # you would hard-code this configuration
  %{unique_column: :id}
)

The reason a unique_column is specified here is to be a “tie breaker” to ensure a unique value for sorting and paginating. See the moduledocs for more details.

If using this, you might put (for example) under your usersConnection:

arg(:sorts, list_of(:user_order_by))

You’d use user_order_by to define the ways you allow sorting for that record type. (You might want to consider what index support you have or need.)

  input_object :user_order_by do
    @desc "By email"
    field(:email, :sort_direction)

    @desc "By first name"
    field(:first_name, :sort_direction)

   # etc
  end

:sort_direction is a simple enum type:

  enum :sort_direction do
    @desc "Ascending (for example, 1,2,3 or a,b,c)."
    value(:asc)
    @desc "Descending (for example, 3,2,1 or c,b,a)."
    value(:desc)
  end

@benwilson512 I’d love to contribute this to absinthe_relay | Hex if you’re interested. If not, I might release it as a separate package.

@nathanl not a guide per-se but some examples from other open source Elixir codebases that may help you:

• With Absinthe Relay

  • Blockscout
    • blockscout/types.ex at master · blockscout/blockscout · GitHub
    • blockscout/transaction_test.exs at master · blockscout/blockscout · GitHub

• Without Absinthe Relay

  • Sanbase
    • sanbase2/pagination_types.ex at master · santiment/sanbase2 · GitHub
    • sanbase2/entity_comment.ex at master · santiment/sanbase2 · GitHub
  • Level
    • level/pagination.ex at master · unstacked/level · GitHub

Hey Nathan! That library is great! I’ve some changes I plan to send as a PR (behaviour for Cursor to allow custom cursor implementations, making and marking the default Cursor as “tamper-resistant”, rather than tamper-proof, using Ecto’s dynamic/2 to allow > 3). Still working on some things, including adding tests for a NaiveDateTime sort, and I’m thinking of allowing the key for sorts to be configurable, although this could also be changed in the resolvers before calling from_query/4.

I’m also planning some tests on nullable columns, to see how it affects sorting (IIRC, == nil isn’t allowed in Ecto, and is_nil/1 should be used instead). Maybe this will be outside the scope though, given that asc and desc don’t cover the cases for all possible sorts:

• :asc
• :asc_nulls_last
• :asc_nulls_first
• :desc
• :desc_nulls_last
• :desc_nulls_first

And I’m not sure if it makes sense to allow all these cases.

FYI - this library is now published at absinthe_relay_keyset_connection | Hex

I don’t have a guide but I recently made a demo project that had cursor based pagination using Relay. Absinthe Relay image upload with Expo React Native