# Pleroma: A lightweight social networking server # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Formatter do alias Pleroma.HTML alias Pleroma.User @safe_mention_regex ~r/^(\s*(?<mentions>(@.+?\s+){1,})+)(?<rest>.*)/s @link_regex ~r"((?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~%:/?#[\]@!\$&'\(\)\*\+,;=.]+)|[0-9a-z+\-\.]+:[0-9a-z$-_.+!*'(),]+"ui @markdown_characters_regex ~r/(`|\*|_|{|}|[|]|\(|\)|#|\+|-|\.|!)/ defp linkify_opts do Pleroma.Config.get(Pleroma.Formatter) ++ [ hashtag: true, hashtag_handler: &Pleroma.Formatter.hashtag_handler/4, mention: true, mention_handler: &Pleroma.Formatter.mention_handler/4 ] end def escape_mention_handler("@" <> nickname = mention, buffer, _, _) do case User.get_cached_by_nickname(nickname) do %User{} -> # escape markdown characters with `\\` # (we don't want something like @user__name to be parsed by markdown) String.replace(mention, @markdown_characters_regex, "\\\\\\1") _ -> buffer end end def mention_handler("@" <> nickname, buffer, opts, acc) do case User.get_cached_by_nickname(nickname) do %User{id: id} = user -> user_url = user.uri || user.ap_id nickname_text = get_nickname_text(nickname, opts) link = Phoenix.HTML.Tag.content_tag( :span, Phoenix.HTML.Tag.content_tag( :a, ["@", Phoenix.HTML.Tag.content_tag(:span, nickname_text)], "data-user": id, class: "u-url mention", href: user_url, rel: "ugc" ), class: "h-card" ) |> Phoenix.HTML.safe_to_string() {link, %{acc | mentions: MapSet.put(acc.mentions, {"@" <> nickname, user})}} _ -> {buffer, acc} end end def hashtag_handler("#" <> tag = tag_text, _buffer, _opts, acc) do tag = String.downcase(tag) url = "#{Pleroma.Web.base_url()}/tag/#{tag}" link = Phoenix.HTML.Tag.content_tag(:a, tag_text, class: "hashtag", "data-tag": tag, href: url, rel: "tag ugc" ) |> Phoenix.HTML.safe_to_string() {link, %{acc | tags: MapSet.put(acc.tags, {tag_text, tag})}} end @doc """ Parses a text and replace plain text links with HTML. Returns a tuple with a result text, mentions, and hashtags. If the 'safe_mention' option is given, only consecutive mentions at the start the post are actually mentioned. """ @spec linkify(String.t(), keyword()) :: {String.t(), [{String.t(), User.t()}], [{String.t(), String.t()}]} def linkify(text, options \\ []) do options = linkify_opts() ++ options if options[:safe_mention] && Regex.named_captures(@safe_mention_regex, text) do %{"mentions" => mentions, "rest" => rest} = Regex.named_captures(@safe_mention_regex, text) acc = %{mentions: MapSet.new(), tags: MapSet.new()} {text_mentions, %{mentions: mentions}} = Linkify.link_map(mentions, acc, options) {text_rest, %{tags: tags}} = Linkify.link_map(rest, acc, options) {text_mentions <> text_rest, MapSet.to_list(mentions), MapSet.to_list(tags)} else acc = %{mentions: MapSet.new(), tags: MapSet.new()} {text, %{mentions: mentions, tags: tags}} = Linkify.link_map(text, acc, options) {text, MapSet.to_list(mentions), MapSet.to_list(tags)} end end @doc """ Escapes a special characters in mention names. """ def mentions_escape(text, options \\ []) do options = Keyword.merge(options, mention: true, url: false, mention_handler: &Pleroma.Formatter.escape_mention_handler/4 ) if options[:safe_mention] && Regex.named_captures(@safe_mention_regex, text) do %{"mentions" => mentions, "rest" => rest} = Regex.named_captures(@safe_mention_regex, text) Linkify.link(mentions, options) <> Linkify.link(rest, options) else Linkify.link(text, options) end end def html_escape({text, mentions, hashtags}, type) do {html_escape(text, type), mentions, hashtags} end def html_escape(text, "text/html") do HTML.filter_tags(text) end def html_escape(text, "text/plain") do Regex.split(@link_regex, text, include_captures: true) |> Enum.map_every(2, fn chunk -> {:safe, part} = Phoenix.HTML.html_escape(chunk) part end) |> Enum.join("") end def truncate(text, max_length \\ 200, omission \\ "...") do # Remove trailing whitespace text = Regex.replace(~r/([^ \t\r\n])([ \t]+$)/u, text, "\\g{1}") if String.length(text) < max_length do text else length_with_omission = max_length - String.length(omission) String.slice(text, 0, length_with_omission) <> omission end end defp get_nickname_text(nickname, %{mentions_format: :full}), do: User.full_nickname(nickname) defp get_nickname_text(nickname, _), do: User.local_nickname(nickname) end