Introduce group basic federation, event new page and notifications

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

lib/service/formatter/oembed.ex

@@ -0,0 +1,34 @@
+defmodule Mobilizon.Service.Formatter.OEmbed do
+  @moduledoc """
+  Custom strategy to filter HTML content in OEmbed html
+  """
+
+  require FastSanitize.Sanitizer.Meta
+  alias FastSanitize.Sanitizer.Meta
+
+  @valid_schemes ~w(https http)
+
+  Meta.strip_comments()
+
+  Meta.allow_tag_with_uri_attributes(:a, ["href"], @valid_schemes)
+  Meta.allow_tag_with_uri_attributes(:img, ["src"], @valid_schemes)
+
+  Meta.allow_tag_with_these_attributes(:audio, ["controls"])
+
+  Meta.allow_tag_with_uri_attributes(:embed, ["src"], @valid_schemes)
+  Meta.allow_tag_with_these_attributes(:embed, ["height type width"])
+
+  Meta.allow_tag_with_uri_attributes(:iframe, ["src"], @valid_schemes)
+
+  Meta.allow_tag_with_these_attributes(
+    :iframe,
+    ["allowfullscreen frameborder allow height scrolling width"]
+  )
+
+  Meta.allow_tag_with_uri_attributes(:source, ["src"], @valid_schemes)
+  Meta.allow_tag_with_these_attributes(:source, ["type"])
+
+  Meta.allow_tag_with_these_attributes(:video, ["controls height loop width"])
+
+  Meta.strip_everything_not_covered()
+end