mobilizon/lib/service/formatter/default_scrubbler.ex

# 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/html.ex

defmodule Mobilizon.Service.Formatter.DefaultScrubbler do
  @moduledoc """
  Custom strategy to filter HTML content.
  """

  require FastSanitize.Sanitizer.Meta
  alias FastSanitize.Sanitizer.Meta

  # credo:disable-for-previous-line
  # No idea how to fix this one…

  @valid_schemes ~w(https http)

  Meta.strip_comments()

  Meta.allow_tag_with_uri_attributes(:a, ["href", "data-user", "data-tag"], @valid_schemes)

  Meta.allow_tag_with_this_attribute_values(:a, "class", [
    "hashtag",
    "u-url",
    "mention",
    "u-url mention",
    "mention u-url"
  ])

  Meta.allow_tag_with_this_attribute_values(:a, "rel", [
    "tag",
    "nofollow",
    "noopener",
    "noreferrer",
    "ugc"
  ])

  # Rel attributes are separated by spaces
  Meta.allow_tag_with_this_attribute_values(:a, "rel", [
    "noopener noreferrer ugc"
  ])

  Meta.allow_tag_with_these_attributes(:a, ["name", "title", "target"])

  Meta.allow_tag_with_these_attributes(:abbr, ["title"])

  Meta.allow_tag_with_these_attributes(:b, [])
  Meta.allow_tag_with_these_attributes(:blockquote, [])
  Meta.allow_tag_with_these_attributes(:br, [])
  Meta.allow_tag_with_these_attributes(:code, [])
  Meta.allow_tag_with_these_attributes(:del, [])
  Meta.allow_tag_with_these_attributes(:em, [])
  Meta.allow_tag_with_these_attributes(:i, [])
  Meta.allow_tag_with_these_attributes(:li, [])
  Meta.allow_tag_with_these_attributes(:ol, [])
  Meta.allow_tag_with_these_attributes(:p, [])
  Meta.allow_tag_with_these_attributes(:pre, [])
  Meta.allow_tag_with_these_attributes(:strong, [])
  Meta.allow_tag_with_these_attributes(:u, [])
  Meta.allow_tag_with_these_attributes(:ul, [])
  Meta.allow_tag_with_uri_attributes(:img, ["src"], @valid_schemes)

  Meta.allow_tag_with_these_attributes(:img, [
    "width",
    "height",
    "class",
    "title",
    "alt",
    "data-media-id"
  ])

  Meta.allow_tag_with_this_attribute_values(:span, "class", ["h-card", "mention"])
  Meta.allow_tag_with_this_attribute_values(:span, "dir", ["ltr", "rtl", "auto"])
  Meta.allow_tag_with_these_attributes(:span, ["data-user"])

  Meta.allow_tag_with_these_attributes(:h1, [])
  Meta.allow_tag_with_these_attributes(:h2, [])
  Meta.allow_tag_with_these_attributes(:h3, [])
  Meta.allow_tag_with_these_attributes(:h4, [])
  Meta.allow_tag_with_these_attributes(:h5, [])
  Meta.allow_tag_with_these_attributes(:hr, [])

  Meta.strip_everything_not_covered()
end