Improve json-ld metadata on event live streams

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/metadata/utils.ex

@@ -29,7 +29,7 @@ defmodule Mobilizon.Service.Metadata.Utils do
   * Slices it to a limit and add an ellipsis character
   * Returns a default description if text is empty
   """
-  @spec process_description(String.t(), String.t(), integer()) :: String.t()
+  @spec process_description(String.t(), String.t(), integer() | nil) :: String.t()
   def process_description(description, locale \\ "en", limit \\ @slice_limit)
   def process_description(nil, locale, limit), do: process_description("", locale, limit)
 
@@ -56,6 +56,8 @@ defmodule Mobilizon.Service.Metadata.Utils do
   defdelegate datetime_to_string(datetime, locale \\ "en", format \\ :medium), to: DateTime
   defdelegate render_address(address), to: Address
 
+  defp maybe_slice(description, nil), do: description
+
   defp maybe_slice(description, limit) do
     if String.length(description) > limit do
       description

lib/web/views/json_ld/object_view.ex

@@ -9,6 +9,9 @@ defmodule Mobilizon.Web.JsonLD.ObjectView do
   alias Mobilizon.Web.JsonLD.ObjectView
   alias Mobilizon.Web.Router.Helpers, as: Routes
 
+  import Mobilizon.Service.Metadata.Utils,
+    only: [process_description: 3]
+
   @spec render(String.t(), map()) :: map()
   def render("group.json", %{group: %Actor{} = group}) do
     res = %{
@@ -54,12 +57,12 @@ defmodule Mobilizon.Web.JsonLD.ObjectView do
       "@context" => "https://schema.org",
       "@type" => "Event",
       "name" => event.title,
-      "description" => event.description,
+      "description" => process_description(event.description, "en", nil),
       # We assume for now performer == organizer
       "performer" => organizer,
       "organizer" => organizer,
-      "location" => render_location(event),
+      "location" => render_all_locations(event),
-      "eventAttendanceMode" => eventAttendanceMode(event),
+      "eventAttendanceMode" => event |> attendance_mode() |> event_attendance_mode(),
       "eventStatus" =>
         if(event.status == :cancelled,
           do: "https://schema.org/EventCancelled",
@@ -164,39 +167,66 @@ defmodule Mobilizon.Web.JsonLD.ObjectView do
   defp reservation_status(:not_approved), do: "https://schema.org/ReservationHold"
   defp reservation_status(_), do: "https://schema.org/ReservationConfirmed"
 
-  @spec render_location(map()) :: map() | nil
+  defp render_all_locations(%Event{} = event) do
-  defp render_location(%{physical_address: %Address{} = address}),
+    []
-    do: render_one(address, ObjectView, "place.json", as: :address)
+    |> render_location(event)
+    |> render_virtual_location(event)
+  end
+
+  @spec render_location(list(), map()) :: list()
+  defp render_location(locations, %{physical_address: %Address{} = address}),
+    do: locations ++ [render_one(address, ObjectView, "place.json", as: :address)]
+
+  defp render_location(locations, _), do: locations
 
   # For now the Virtual Location of an event is it's own URL,
   # but in the future it will be a special field
-  defp render_location(%Event{url: event_url}) do
+  defp render_virtual_location(locations, %Event{
-    %{
+         url: event_url,
-      "@type" => "VirtualLocation",
+         metadata: metadata,
-      "url" => event_url
+         options: %EventOptions{is_online: is_online}
-    }
+       }) do
+    links = virtual_location_links(metadata)
+    fallback_links = if is_online, do: [event_url], else: []
+    links = if length(links) > 0, do: Enum.map(links, & &1.value), else: fallback_links
+
+    locations ++
+      Enum.map(
+        links,
+        &%{
+          "@type" => "VirtualLocation",
+          "url" => &1
+        }
+      )
   end
 
-  defp render_location(_), do: nil
+  defp render_virtual_location(locations, _), do: locations
 
   defp render_address(%{physical_address: %Address{} = address}),
     do: render_one(address, ObjectView, "address.json", as: :address)
 
   defp render_address(_), do: nil
 
-  @livestream_keys ["mz:live", "mz:visio"]
+  defp event_attendance_mode(:online), do: "https://schema.org/OnlineEventAttendanceMode"
+  defp event_attendance_mode(:offline), do: "https://schema.org/OfflineEventAttendanceMode"
+  defp event_attendance_mode(:mixed), do: "https://schema.org/MixedEventAttendanceMode"
 
-  defp eventAttendanceMode(%Event{options: %EventOptions{is_online: true}}),
+  defp attendance_mode(%Event{options: %EventOptions{is_online: true}}),
-    do: "https://schema.org/OnlineEventAttendanceMode"
+    do: :online
 
-  defp eventAttendanceMode(%Event{physical_address: %Address{}, metadata: metadata}) do
+  defp attendance_mode(%Event{physical_address: %Address{}, metadata: metadata}) do
-    if Enum.any?(metadata, &String.contains?(&1["key"], @livestream_keys)) do
+    if metadata |> virtual_location_links() |> length() > 0 do
-      "https://schema.org/MixedEventAttendanceMode"
+      :mixed
     else
-      "https://schema.org/OfflineEventAttendanceMode"
+      :offline
     end
   end
 
-  defp eventAttendanceMode(%Event{}),
+  defp attendance_mode(%Event{}),
-    do: "https://schema.org/OfflineEventAttendanceMode"
+    do: :offline
+
+  @livestream_keys ["mz:live", "mz:visio"]
+  @spec virtual_location_links(list()) :: list()
+  defp virtual_location_links(metadata),
+    do: Enum.filter(metadata, &String.contains?(&1.key, @livestream_keys))
 end