mobilizon.chapril.org-mobil.../lib/service/formatter/formatter.ex
Thomas Citharel c8735e5837
Fix parsing links with hashtag characters
Closes #1008

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2022-01-18 12:46:33 +01:00

166 lines
5.2 KiB
Elixir

# Portions of this file are derived from Pleroma:
# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social>
# SPDX-License-Identifier: AGPL-3.0-only
# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/formatter.ex
defmodule Mobilizon.Service.Formatter do
@moduledoc """
Formats input text to structured data, extracts mentions and hashtags.
"""
alias Mobilizon.Actors
alias Mobilizon.Actors.Actor
alias Mobilizon.Service.Formatter.HTML
alias Phoenix.HTML.Tag
alias Mobilizon.Web.Endpoint
# https://github.com/rrrene/credo/issues/912
# credo:disable-for-next-line Credo.Check.Readability.MaxLineLength
@link_regex ~r"((?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~%:/?#[\]@!\$&'\(\)\*\+,;=.]+)|[0-9a-z+\-\.]+:[0-9a-z$-_.+!*'(),]+"ui
@markdown_characters_regex ~r/(`|\*|_|{|}|[|]|\(|\)|#|\+|-|\.|!)/
@spec escape_mention_handler(String.t(), String.t(), any(), any()) :: String.t()
defp escape_mention_handler("@" <> nickname = mention, buffer, _, _) do
case Actors.get_actor_by_name(nickname) do
%Actor{} ->
# escape markdown characters with `\\`
# (we don't want something like @user__name to be parsed by markdown)
String.replace(mention, @markdown_characters_regex, "\\\\\\1")
nil ->
buffer
end
end
@spec mention_handler(String.t(), String.t(), any(), map()) :: {String.t(), map()}
def mention_handler("@" <> nickname, buffer, _opts, acc) do
case Actors.get_actor_by_name(nickname) do
# %Actor{preferred_username: preferred_username} = actor ->
# link = "<span class='h-card mention'>@<span>#{preferred_username}</span></span>"
#
# {link, %{acc | mentions: MapSet.put(acc.mentions, {"@" <> nickname, actor})}}
%Actor{type: :Person, id: id, preferred_username: preferred_username} = actor ->
# link =
# "<span class='h-card mention' data-user='#{id}'>@<span>#{preferred_username}</span></span>"
link =
Tag.content_tag(
:span,
[
"@",
Tag.content_tag(
:span,
preferred_username
)
],
"data-user": id,
class: "h-card mention"
)
|> Phoenix.HTML.safe_to_string()
{link, %{acc | mentions: MapSet.put(acc.mentions, {"@" <> nickname, actor})}}
nil ->
{buffer, acc}
end
end
@spec hashtag_handler(String.t(), String.t(), any(), map()) :: {String.t(), map()}
def hashtag_handler("#" <> tag = tag_text, _buffer, _opts, acc) do
tag = String.downcase(tag)
url = "#{Endpoint.url()}/tag/#{tag}"
link =
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.
"""
@spec linkify(String.t(), keyword()) ::
{String.t(), [{String.t(), Actor.t()}], [{String.t(), String.t()}]}
def linkify(text, options \\ []) do
options = linkify_opts() ++ options
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
@doc """
Escapes a special characters in mention names.
"""
@spec mentions_escape(String.t(), Keyword.t()) :: String.t()
def mentions_escape(text, options \\ []) do
options =
Keyword.merge(options,
mention: true,
url: false,
mention_handler: &escape_mention_handler/4
)
Linkify.link(text, options)
end
@spec html_escape(
{text :: String.t(), mentions :: list(), hashtags :: list()},
type :: String.t()
) :: {String.t(), list(), list()}
@spec html_escape(text :: String.t(), type :: String.t()) :: String.t()
def html_escape({text, mentions, hashtags}, type) do
{html_escape(text, type), mentions, hashtags}
end
def html_escape(text, "text/html") do
with {:ok, content} <- HTML.filter_tags(text) do
content
end
end
def html_escape(text, "text/plain") do
@link_regex
|> Regex.split(text, include_captures: true)
|> Enum.map_every(2, fn chunk ->
{:safe, part} = Phoenix.HTML.html_escape(chunk)
part
end)
|> Enum.join("")
end
@spec truncate(String.t(), non_neg_integer(), String.t()) :: String.t()
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
@spec linkify_opts :: Keyword.t()
defp linkify_opts do
Mobilizon.Config.get(__MODULE__) ++
[
hashtag: true,
hashtag_handler: &__MODULE__.hashtag_handler/4,
mention: true,
mention_handler: &__MODULE__.mention_handler/4
]
end
end