defmodule MusicLibraryWeb.Pagination do
use Phoenix.Component
use Gettext, backend: MusicLibraryWeb.Gettext
attr :pagination_params, :map, required: true
def pagination(assigns) do
page_links = generate_page_links(assigns.pagination_params)
assigns = assign(assigns, :page_links, page_links)
~H"""
"""
end
defp justify_content(nil, _next_page), do: "justify-end"
defp justify_content(_prev_page, nil), do: "justify-start"
defp justify_content(_prev_page, _next_page), do: "justify-between"
attr :page_number, :integer, required: true
attr :page_size, :integer, required: true
attr :query, :string, required: true
defp next_link(assigns) do
~H"""
<.link
class="relative inline-flex items-center rounded-r-md px-2 py-2 text-gray-400 ring-1 ring-inset ring-gray-300 hover:bg-gray-50 focus:z-20 focus:outline-offset-0"
patch={"?" <> encode_query(page: @page_number, page_size: @page_size, query: @query)}
>
Next
"""
end
attr :page_number, :integer, required: true
attr :page_size, :integer, required: true
attr :query, :string, required: true
defp prev_link(assigns) do
~H"""
<.link
class="relative inline-flex items-center rounded-l-md px-2 py-2 text-gray-400 ring-1 ring-inset ring-gray-300 hover:bg-gray-50 focus:z-20 focus:outline-offset-0"
patch={"?" <> encode_query(page: @page_number, page_size: @page_size, query: @query)}
>
Previous
"""
end
defp separator(assigns) do
~H"""
...
"""
end
attr :page_number, :integer, required: true
attr :page_size, :integer, required: true
attr :active, :boolean, default: false
attr :query, :string, required: true
defp numbered_link(assigns) when assigns.active do
~H"""
<%= @page_number %>
"""
end
defp numbered_link(assigns) do
~H"""
<.link
class="relative hidden items-center first:rounded-l-md last:rounded-r-md px-4 py-2 text-sm font-semibold text-gray-900 ring-1 ring-inset ring-gray-300 hover:bg-gray-50 focus:z-20 focus:outline-offset-0 md:inline-flex"
patch={"?" <> encode_query(page: @page_number, page_size: @page_size, query: @query)}
>
<%= @page_number %>
"""
end
def page_to_offset(page, per_page) do
(page - 1) * per_page
end
defp total_pages(total_entries, page_size) do
without_remainder = div(total_entries, page_size)
if rem(total_entries, page_size) == 0 do
without_remainder
else
without_remainder + 1
end
end
defp encode_query(params) do
params
|> Enum.filter(fn {_, v} -> v not in ["", nil] end)
|> URI.encode_query()
end
@visible_left_pages 3
@visible_right_pages 3
@middle "..."
defp generate_page_links(pagination_params) do
%{
total_entries: total_entries,
page: page,
page_size: page_size
} = pagination_params
total_pages = total_pages(total_entries, page_size)
all_pages = Enum.to_list(1..total_pages)
{left_pages, middle_pages, right_pages} =
Enum.reduce(all_pages, {[], [], []}, fn p, {left_p, middle_p, right_p} ->
cond do
p < page - 2 ->
{left_p ++ [p], middle_p, right_p}
p > page + 2 ->
{left_p, middle_p, right_p ++ [p]}
true ->
{left_p, middle_p ++ [p], right_p}
end
end)
prev_page = if page > 1, do: page - 1
next_page = if page < total_pages, do: page + 1
left_separator = if Enum.count(left_pages) > @visible_left_pages, do: @middle
right_separator = if Enum.count(right_pages) > @visible_right_pages, do: @middle
visible_left_pages = Enum.take(left_pages, @visible_left_pages)
visible_right_pages = Enum.take(right_pages, -@visible_right_pages)
%{
query: pagination_params.query,
total_pages: total_pages,
prev_page: prev_page,
visible_left_pages: visible_left_pages,
left_separator: left_separator,
middle_pages: middle_pages,
right_separator: right_separator,
visible_right_pages: visible_right_pages,
next_page: next_page
}
end
end