spc-pleroma/lib/pleroma/web/metadata/providers/open_graph.ex

149 lines
4.9 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.Web.Metadata.Providers.OpenGraph do
alias Pleroma.User
alias Pleroma.Web.MediaProxy
alias Pleroma.Web.Metadata
alias Pleroma.Web.Metadata.Providers.Provider
alias Pleroma.Web.Metadata.Utils
@behaviour Provider
@media_types ["image", "audio", "video"]
@impl Provider
def build_tags(%{
object: object,
url: url,
user: user
}) do
attachments = build_attachments(object)
scrubbed_content = Utils.scrub_html_and_truncate(object)
[
{:meta,
[
property: "og:title",
content: Utils.user_name_string(user)
], []},
{:meta, [property: "og:url", content: url], []},
{:meta,
[
property: "og:description",
content: scrubbed_content
], []},
{:meta, [property: "og:type", content: "article"], []}
] ++
if attachments == [] or Metadata.activity_nsfw?(object) do
[
{:meta, [property: "og:image", content: MediaProxy.preview_url(User.avatar_url(user))],
[]},
{:meta, [property: "og:image:width", content: 150], []},
{:meta, [property: "og:image:height", content: 150], []}
]
else
attachments
end
end
@impl Provider
def build_tags(%{user: user}) do
with truncated_bio = Utils.scrub_html_and_truncate(user.bio) do
[
{:meta,
[
property: "og:title",
content: Utils.user_name_string(user)
], []},
{:meta, [property: "og:url", content: user.uri || user.ap_id], []},
{:meta, [property: "og:description", content: truncated_bio], []},
{:meta, [property: "og:type", content: "article"], []},
{:meta, [property: "og:image", content: MediaProxy.preview_url(User.avatar_url(user))],
[]},
{:meta, [property: "og:image:width", content: 150], []},
{:meta, [property: "og:image:height", content: 150], []}
]
end
end
defp build_attachments(%{data: %{"attachment" => attachments}}) do
Enum.reduce(attachments, [], fn attachment, acc ->
rendered_tags =
Enum.reduce(attachment["url"], [], fn url, acc ->
# TODO: Whatsapp only wants JPEG or PNGs. It seems that if we add a second og:image
# object when a Video or GIF is attached it will display that in Whatsapp Rich Preview.
case Utils.fetch_media_type(@media_types, url["mediaType"]) do
"audio" ->
[
{:meta, [property: "og:audio", content: MediaProxy.url(url["href"])], []}
| acc
]
# Not using preview_url for this. It saves bandwidth, but the image dimensions will
# be wrong. We generate it on the fly and have no way to capture or analyze the
# image to get the dimensions. This can be an issue for apps/FEs rendering images
# in timelines too, but you can get clever with the aspect ratio metadata as a
# workaround.
"image" ->
[
{:meta, [property: "og:image", content: MediaProxy.url(url["href"])], []},
{:meta, [property: "og:image:alt", content: attachment["name"]], []}
| acc
]
|> maybe_add_dimensions(url)
"video" ->
[
{:meta, [property: "og:video", content: MediaProxy.url(url["href"])], []}
| acc
]
|> maybe_add_dimensions(url)
|> maybe_add_video_thumbnail(url)
_ ->
acc
end
end)
acc ++ rendered_tags
end)
end
defp build_attachments(_), do: []
# We can use url["mediaType"] to dynamically fill the metadata
defp maybe_add_dimensions(metadata, url) do
type = url["mediaType"] |> String.split("/") |> List.first()
cond do
!is_nil(url["height"]) && !is_nil(url["width"]) ->
metadata ++
[
{:meta, [property: "og:#{type}:width", content: "#{url["width"]}"], []},
{:meta, [property: "og:#{type}:height", content: "#{url["height"]}"], []}
]
true ->
metadata
end
end
# Media Preview Proxy makes thumbnails of videos without resizing, so we can trust the
# width and height of the source video.
defp maybe_add_video_thumbnail(metadata, url) do
cond do
Pleroma.Config.get([:media_preview_proxy, :enabled], false) ->
metadata ++
[
{:meta, [property: "og:image:width", content: "#{url["width"]}"], []},
{:meta, [property: "og:image:height", content: "#{url["height"]}"], []},
{:meta, [property: "og:image", content: MediaProxy.preview_url(url["href"])], []}
]
true ->
metadata
end
end
end