1 # Pleroma: A lightweight social networking server
3 # Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
4 # SPDX-License-Identifier: AGPL-3.0-only
6 defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
8 alias Pleroma.Web.MediaProxy
9 alias Pleroma.Web.Metadata
10 alias Pleroma.Web.Metadata.Providers.Provider
11 alias Pleroma.Web.Metadata.Utils
14 @media_types ["image", "audio", "video"]
17 def build_tags(%{activity_id: id, object: object, user: user}) do
18 attachments = build_attachments(id, object)
19 scrubbed_content = Utils.scrub_html_and_truncate(object)
23 {:meta, [name: "twitter:description", content: scrubbed_content], []}
25 if attachments == [] or Metadata.activity_nsfw?(object) do
28 {:meta, [name: "twitter:card", content: "summary"], []}
36 def build_tags(%{user: user}) do
37 with truncated_bio = Utils.scrub_html_and_truncate(user.bio) do
40 {:meta, [name: "twitter:description", content: truncated_bio], []},
42 {:meta, [name: "twitter:card", content: "summary"], []}
47 defp title_tag(user) do
48 {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []}
51 def image_tag(user) do
52 {:meta, [name: "twitter:image", content: MediaProxy.preview_url(User.avatar_url(user))], []}
55 defp build_attachments(id, %{data: %{"attachment" => attachments}}) do
56 Enum.reduce(attachments, [], fn attachment, acc ->
58 Enum.reduce(attachment["url"], [], fn url, acc ->
59 case Utils.fetch_media_type(@media_types, url["mediaType"]) do
62 {:meta, [name: "twitter:card", content: "player"], []},
63 {:meta, [name: "twitter:player:width", content: "480"], []},
64 {:meta, [name: "twitter:player:height", content: "80"], []},
65 {:meta, [name: "twitter:player", content: player_url(id)], []}
69 # Not using preview_url for this. It saves bandwidth, but the image dimensions will
70 # be wrong. We generate it on the fly and have no way to capture or analyze the
71 # image to get the dimensions. This can be an issue for apps/FEs rendering images
72 # in timelines too, but you can get clever with the aspect ratio metadata as a
76 {:meta, [name: "twitter:card", content: "summary_large_image"], []},
79 name: "twitter:player",
80 content: MediaProxy.url(url["href"])
84 |> maybe_add_dimensions(url)
87 # fallback to old placeholder values
88 height = url["height"] || 480
89 width = url["width"] || 480
92 {:meta, [name: "twitter:card", content: "player"], []},
93 {:meta, [name: "twitter:player", content: player_url(id)], []},
94 {:meta, [name: "twitter:player:width", content: "#{width}"], []},
95 {:meta, [name: "twitter:player:height", content: "#{height}"], []},
96 {:meta, [name: "twitter:player:stream", content: MediaProxy.url(url["href"])],
98 {:meta, [name: "twitter:player:stream:content_type", content: url["mediaType"]],
112 defp build_attachments(_id, _object), do: []
114 defp player_url(id) do
115 Pleroma.Web.Router.Helpers.o_status_url(Pleroma.Web.Endpoint, :notice_player, id)
118 # Videos have problems without dimensions, but we used to not provide WxH for images.
119 # A default (read: incorrect) fallback for images is likely to cause rendering bugs.
120 defp maybe_add_dimensions(metadata, url) do
122 !is_nil(url["height"]) && !is_nil(url["width"]) ->
125 {:meta, [name: "twitter:player:width", content: "#{url["width"]}"], []},
126 {:meta, [name: "twitter:player:height", content: "#{url["height"]}"], []}