# Pleroma: A lightweight social networking server # Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Web.Metadata.Providers.OpenGraph do alias Pleroma.Web.Metadata.Providers.Provider alias Pleroma.Web.Metadata alias Pleroma.{HTML, Formatter, User} alias Pleroma.Web.MediaProxy @behaviour Provider @impl Provider def build_tags(%{ object: object, user: user }) do attachments = build_attachments(object) scrubbed_content = scrub_html_and_truncate(object) # Zero width space content = if scrubbed_content != "" and scrubbed_content != "\u200B" do ": “" <> scrubbed_content <> "”" else "" end # Most previews only show og:title which is inconvenient. Instagram # hacks this by putting the description in the title and making the # description longer prefixed by how many likes and shares the post # has. Here we use the descriptive nickname in the title, and expand # the full account & nickname in the description. We also use the cute^Wevil # smart quotes around the status text like Instagram, too. [ {:meta, [ property: "og:title", content: "#{user.name}" <> content ], []}, {:meta, [property: "og:url", content: object.data["id"]], []}, {:meta, [ property: "og:description", content: "#{user_name_string(user)}" <> content ], []}, {:meta, [property: "og:type", content: "website"], []} ] ++ if attachments == [] or Metadata.activity_nsfw?(object) do [ {:meta, [property: "og:image", content: attachment_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 = scrub_html_and_truncate(user.bio || "") do [ {:meta, [ property: "og:title", content: user_name_string(user) ], []}, {:meta, [property: "og:url", content: User.profile_url(user)], []}, {:meta, [property: "og:description", content: truncated_bio], []}, {:meta, [property: "og:type", content: "website"], []}, {:meta, [property: "og:image", content: attachment_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 -> media_type = Enum.find(["image", "audio", "video"], fn media_type -> String.starts_with?(url["mediaType"], media_type) end) # TODO: Add additional properties to objects when we have the data available. # Also, 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 the Whatsapp Rich Preview. case media_type do "audio" -> [ {:meta, [property: "og:" <> media_type, content: attachment_url(url["href"])], []} | acc ] "image" -> [ {:meta, [property: "og:" <> media_type, content: attachment_url(url["href"])], []}, {:meta, [property: "og:image:width", content: 150], []}, {:meta, [property: "og:image:height", content: 150], []} | acc ] "video" -> [ {:meta, [property: "og:" <> media_type, content: attachment_url(url["href"])], []} | acc ] _ -> acc end end) acc ++ rendered_tags end) end defp scrub_html_and_truncate(%{data: %{"content" => content}} = object) do content # html content comes from DB already encoded, decode first and scrub after |> HtmlEntities.decode() |> String.replace(~r/<br\s?\/?>/, " ") |> HTML.get_cached_stripped_html_for_object(object, __MODULE__) |> Formatter.demojify() |> Formatter.truncate() end defp scrub_html_and_truncate(content) when is_binary(content) do content # html content comes from DB already encoded, decode first and scrub after |> HtmlEntities.decode() |> String.replace(~r/<br\s?\/?>/, " ") |> HTML.strip_tags() |> Formatter.demojify() |> Formatter.truncate() end defp attachment_url(url) do MediaProxy.url(url) end defp user_name_string(user) do "#{user.name} " <> if user.local do "(@#{user.nickname}@#{Pleroma.Web.Endpoint.host()})" else "(@#{user.nickname})" end end end