-
- @doc """
- Get sanitized HTML from cache, or scrub it and save to cache.
- """
- def get_scrubbed_html(
- content,
- scrubbers,
- %{data: %{"object" => object}} = activity
- ) do
- scrubber_cache =
- if is_list(object["scrubber_cache"]) do
- object["scrubber_cache"]
- else
- []
- end
-
- signature = generate_scrubber_signature(scrubbers)
-
- {new_scrubber_cache, scrubbed_html} =
- Enum.map_reduce(scrubber_cache, nil, fn
- entry, _content ->
- if Map.keys(entry["scrubbers"]) == Map.keys(signature) do
- if entry["scrubbers"] == signature do
- {entry, entry["content"]}
- else
- # Remove the entry if scrubber version is outdated
- {nil, nil}
- end
- end
- end)
-
- # Remove nil objects
- new_scrubber_cache = Enum.reject(new_scrubber_cache, &is_nil/1)
-
- if scrubbed_html == nil or new_scrubber_cache != scrubber_cache do
- scrubbed_html = HTML.filter_tags(content, scrubbers)
- new_scrubber_cache = [%{:scrubbers => signature, :content => scrubbed_html} | new_scrubber_cache]
- update_scrubber_cache(activity, new_scrubber_cache)
- end
- scrubbed_html
- end
-
- defp generate_scrubber_signature(scrubbers) do
- Enum.reduce(scrubbers, %{}, fn scrubber, signature ->
- Map.put(signature, to_string(scrubber), scrubber.version)
- end)
- end
-
- defp update_scrubber_cache(activity, scrubber_cache) do
- cng =
- Object.change(activity, %{
- data: Kernel.put_in(activity.data, ["object", "scrubber_cache"], scrubber_cache)
- })
-
- {:ok, _struct} = Repo.update(cng)
- end