Scrivener.List

Scrivener.List is a Scrivener compatible extension that allows the pagination of a list of elements.

Features

1. Scrivener.List extends the protocol Scrivener.Paginater.paginate/2 from the scrivener library.
2. Scrivener.List also extends the function MyApp.Repo.paginate/2 from the scrivener_ecto library.

Using the second feature is entirely optional. It's provided as a convenience where the scrivener_ecto library is also being used in the project and gives access to the pre-configured MyApp.Repo module.

Usage

1. Usage without a Repo module

Scrivener.paginate(list, config)

Arguments (without a repo)

• list: A list of elements to be paginated

• config: A configuration object with the pagination details. Can be in any of the following formats:

  • %{page: page_number, page_size: page_size} (map)
  • [page: page_number, page_size: page_size] (Keyword.t)
  • %Scrivener.Config{page_number: page_number, page_size: page_size} (Scrivener.Config.t)

max_page_size cannot be configured with method 1.

Examples

def index(conn, params) do
  config = maybe_put_default_config(params)

  page = 
    ["C#", "C++", "Clojure", "Elixir", "Erlang", "Go", "JAVA", "JavaScript", "Lisp",
      "PHP", "Perl", "Python", "Ruby", "Rust", "SQL"]
    |> Enum.map(&(&1 <> "  " <> "language"))
    |> Scrivener.paginate(config)

  render conn, :index,
    people: page.entries,
    page_number: page.page_number,
    page_size: page.page_size,
    total_pages: page.total_pages,
    total_entries: page.total_entries
end

defp maybe_put_default_config(%{page: page_number, page_size: page_size} = params), do: params
defp maybe_put_default_config(_params), do: %Scrivener.Config{page_number: 1, page_size: 10}

list = ["C#", "C++", "Clojure", "Elixir", "Erlang", "Go", "JAVA", "JavaScript", "Lisp",
        "PHP", "Perl", "Python", "Ruby", "Rust", "SQL"]
        
Scrivener.paginate(list, %Scrivener.Config{page_number: 1, page_size: 4}) # %Scrivener.Config{}
Scrivener.paginate(list, page: 1, page_size: 4) # keyword list
Scrivener.paginate(list, %{page: 1, page_size: 4}) # map
Scrivener.paginate(list, %{page: 1}) # map with only page number (page_size defaults to 10)

2. Usage with a Repo module

Usage without a Repo is entirely optional and is added to Scrivener.List for convenience. Firstly, see Scrivener.Ecto and configure the MyApp.Repo module.

Example Repo configuration

defmodule MyApp.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres
  use Scrivener,
    page_size: 10,
    max_page_size: 100
end

MyApp.Repo.paginate(list, config)

Arguments (with a repo)

• list: A list of elements to be paginated

• config: A configuration object with the pagination details. Can be in any of the following formats:

  • %{page: page_number, page_size: page_size} (map)
  • [page: page_number, page_size: page_size] (Keyword.t)

max_page_size can be configured with method 1. See Scrivener.Ecto.

Example

Example based on scrivener_ecto readme.

def index(conn, params) do
  %{age: age, name: name} = params["search"] 
  
  page = MyApp.Person
  |> where([p], p.age > ^age)
  |> order_by([p], desc: p.age)
  |> preload(:friends)
  |> MyApp.Repo.all()
  |> Enum.filter(fn(person) -> person.data.friend.name = name end)
  |> MyApp.Repo.paginate(params)

  render conn, :index,
    people: page.entries,
    page_number: page.page_number,
    page_size: page.page_size,
    total_pages: page.total_pages,
    total_entries: page.total_entries
end

Installation

Add scrivener_list to your list of dependencies in mix.exs:

def deps do
  [
    {:scrivener_list, "~> 2.0"}
  ]
end

Tests

MIX_ENV=test mix test

Acknowledgements

The introduction of the protocol for scrivener enabled the separation of this package into it's own repository.

Licence

MIT