1 defmodule Pleroma.Pagination do
3 Implements Mastodon-compatible pagination.
13 def fetch_paginated(query, params) do
14 options = cast_params(params)
19 |> enforce_order(options)
22 def paginate(query, options) do
24 |> restrict(:min_id, options)
25 |> restrict(:since_id, options)
26 |> restrict(:max_id, options)
27 |> restrict(:order, options)
28 |> restrict(:limit, options)
31 defp cast_params(params) do
40 Enum.reduce(params, %{}, fn
41 {key, _value}, acc when is_atom(key) -> Map.drop(acc, [key])
42 {key, value}, acc -> Map.put(acc, key, value)
45 changeset = cast({%{}, param_types}, params, Map.keys(param_types))
49 defp restrict(query, :min_id, %{min_id: min_id}) do
50 where(query, [q], q.id > ^min_id)
53 defp restrict(query, :since_id, %{since_id: since_id}) do
54 where(query, [q], q.id > ^since_id)
57 defp restrict(query, :max_id, %{max_id: max_id}) do
58 where(query, [q], q.id < ^max_id)
61 defp restrict(query, :order, %{min_id: _}) do
62 order_by(query, [u], fragment("? asc nulls last", u.id))
65 defp restrict(query, :order, _options) do
66 order_by(query, [u], fragment("? desc nulls last", u.id))
69 defp restrict(query, :limit, options) do
70 limit = Map.get(options, :limit, @default_limit)
76 defp restrict(query, _, _), do: query
78 defp enforce_order(result, %{min_id: _}) do
83 defp enforce_order(result, _), do: result