mobilizon/lib/federation/web_finger/xml_builder.ex

55 lines
1.8 KiB
Elixir

# Portions of this file are derived from Pleroma:
# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social>
# SPDX-License-Identifier: AGPL-3.0-only
# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/xml_builder.ex
defmodule Mobilizon.Federation.WebFinger.XmlBuilder do
@moduledoc """
Extremely basic XML encoder. Builds XRD for WebFinger host_meta.
"""
@typep content :: list({tag :: atom(), attributes :: map()}) | String.t()
@typep document :: {tag :: atom(), attributes :: map(), content :: content}
@doc """
Return the XML representation for a document.
"""
@spec to_doc(document :: document) :: String.t()
def to_doc(document), do: ~s(<?xml version="1.0" encoding="UTF-8"?>) <> to_xml(document)
@spec to_xml(document) :: String.t()
@spec to_xml({tag :: atom(), attributes :: map()}) :: String.t()
@spec to_xml({tag :: atom(), content :: content}) :: String.t()
@spec to_xml(content :: content) :: String.t()
defp to_xml({tag, attributes, content}) do
open_tag = make_open_tag(tag, attributes)
content_xml = to_xml(content)
"<#{open_tag}>#{content_xml}</#{tag}>"
end
defp to_xml({tag, %{} = attributes}) do
open_tag = make_open_tag(tag, attributes)
"<#{open_tag} />"
end
defp to_xml({tag, content}), do: to_xml({tag, %{}, content})
defp to_xml(content) when is_binary(content), do: to_string(content)
defp to_xml(content) when is_list(content) do
Enum.map_join(content, &to_xml/1)
end
defp to_xml(%NaiveDateTime{} = time), do: NaiveDateTime.to_iso8601(time)
@spec make_open_tag(tag :: atom, attributes :: map()) :: String.t()
defp make_open_tag(tag, attributes) do
attributes_string =
Enum.map_join(attributes, " ", fn {attribute, value} -> "#{attribute}=\"#{value}\"" end)
[to_string(tag), attributes_string] |> Enum.join(" ") |> String.trim()
end
end