Packages

scrivener

0.1.0
2.7.2 2.7.1 2.7.0 2.6.0 2.5.0 2.4.0 2.3.0 2.2.1 2.2.0 2.1.1 2.1.0 2.0.0 1.2.2 1.2.1 1.2.0 1.1.4 1.1.3 1.1.2 1.1.1 1.1.0 1.0.0 0.13.0 0.12.0 0.11.0 0.10.0 0.9.0 0.8.0 0.7.1 0.7.0 0.6.0 0.5.1 0.5.0 0.4.0 0.3.0 0.2.2 0.2.1 0.2.0 0.1.0

Pagination for the Elixir ecosystem

HexDocs

Current section

Files

Jump to
Readme
38 Versions
1 Dependency
17 Dependants
Files
Activity
scrivener lib scrivener.ex
Raw

lib/scrivener.ex 

defmodule Scrivener do

  import Ecto.Query



  alias Scrivener.Config



  def paginate(query) do

    paginate(query, Config.new)

  end



  def paginate(query, opts) when is_list(opts) do

    paginate(query, Config.new(opts))

  end



  def paginate(query, %Config{} = config) do

    %Scrivener.Page{

      page_size: config.page_size,

      page_number: config.page_number,

      records: records(query, config.repo, config.page_number, config.page_size),

      total_pages: total_pages(query, config.repo, config.page_size)

    }

  end



  def paginate(query, %{} = params, opts \\ []) do

    config = Config.new(params, opts)

    paginate(query, config)

  end



  defp ceiling(float) do

    t = trunc(float)



    case float - t do

      neg when neg < 0 ->

        t

      pos when pos > 0 ->

        t + 1

      _ -> t

    end

  end





  defp records(query, repo, page_number, page_size) do

    offset = page_size * (page_number - 1)



    query

    |> limit([_], ^page_size)

    |> offset([_], ^offset)

    |> repo.all

  end



  def total_pages(query, repo, page_size) do

    count = query

    |> exclude(:order_by)

    |> exclude(:preload)

    |> exclude(:select)

    |> select([e], count(e.id))

    |> repo.one



    ceiling(count / page_size)

  end

end