pleroma/lib/pleroma/formatter.ex
2022-02-25 23:11:42 -07:00

161 lines
5.1 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2022 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{} = user ->
{mention_from_user(user, opts),
%{acc | mentions: MapSet.put(acc.mentions, {"@" <> nickname, user})}}
_ ->
{buffer, acc}
end
end
def mention_from_user(%User{id: id} = user, opts \\ %{mentions_format: :full}) do
user_url = user.uri || user.ap_id
nickname_text = get_nickname_text(user.nickname, opts)
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()
end
def hashtag_handler("#" <> tag = tag_text, _buffer, _opts, acc) do
tag = String.downcase(tag)
url = "#{Pleroma.Web.Endpoint.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 markdown_to_html(text) do
Earmark.as_html!(text, %Earmark.Options{compact_output: true})
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