Ecto.CursorPagination

Cursor Pagination

Good Explanation of why cursor pagination is superior to offset/limit:

http://blog.novatec-gmbh.de/art-pagination-offset-vs-value-based-paging/ https://www.percona.com/files/presentations/ppc2009/PPC2009_mysql_pagination.pdf

Installation

If available in Hex, the package can be installed as:

1. Add ecto_cursor_pagination to your list of dependencies in mix.exs:

   def deps do
     [{:ecto_cursor_pagination, "~> 0.1.1"}]
   end

2. Ensure ecto_cursor_pagination is started before your application:

   def application do
     [applications: [:ecto_cursor_pagination]]
   end

Recommended Setup

• Configure this application

  • Add to your config/config.exs or each config/env_name.exs:

    config :ecto_cursor_pagination,
      per_page: 15,
      cursor_id: :id

Example controller Action

def index(conn, params) do
  last_seen_param = Map.get(params, "last_seen_id", "")
  direction_param = Map.get(params, "dir", "")

  query = Todo
          |> filter_by_uuid("user_id", params["user_id"])
          |> filter_by_string("name", params["name"])
          |> filter_by_string("type", params["type"])
  query = Ecto.CursorPagination.paginate(query, last_seen_param, direction_param)

  render(conn, "index.json", data: MyApp.Repo.all(query))
end

Contributing

Before submitting your pull request, please run:

• mix credo --strict
• mix coveralls
• mix dialyzer

Please squash your pull request’s commits into a single commit with a message and detailed description explaining the commit.