Save associations changes in items_changes

lib/paper_trail.ex

@@ -253,7 +253,7 @@ defmodule PaperTrail do
       event: "update",
       item_type: changeset.data.__struct__ |> Module.split |> List.last,
       item_id: changeset.data.id,
-      item_changes: changeset.changes,
+      item_changes: serialize_changes(changeset) || %{},
       originator_id: case originator_ref do
         nil -> nil
         _ -> originator_ref |> Map.get(:id)
@@ -298,6 +298,44 @@ defmodule PaperTrail do
     Map.drop(model, [:__struct__, :__meta__] ++ relationships)
   end
 
+  defp serialize_changes(data), do: serialize_changes(data, true)
+  defp serialize_changes(data, is_root) do
+    case is_map(data) do
+      false -> data
+      true -> deep_serialize(data, is_root)
+    end
+  end
+
+  defp deep_serialize(data, is_root) do
+    if Map.has_key?(data, :__struct__) do
+      case data.__struct__ do
+        Ecto.Changeset -> extract_values(data, is_root)
+        _ -> data
+      end
+    else
+      data
+    end
+  end
+
+  defp extract_values(changeset, is_root) do
+    if changeset.changes != %{} do
+      init = initial_value(changeset, is_root)
+      changeset.changes
+      |> Enum.reduce(init, fn({key, value}, accum) ->
+        value = if is_list(value) do
+          Enum.map(value, &serialize_changes(&1, false))
+          |> Enum.filter(fn(v) -> ! is_nil(v) end)
+        else
+          serialize_changes(value, false)
+        end
+        Map.put(accum, key, value)
+      end)
+    end
+  end
+
+  defp initial_value(_, true), do: %{}
+  defp initial_value(changeset, false), do: %{id: changeset.data.id}
+
   defp add_prefix(changeset, nil), do: changeset
   defp add_prefix(changeset, prefix), do: Ecto.put_meta(changeset, prefix: prefix)
 end

test/paper_trail_test.exs

@@ -10,6 +10,7 @@ defmodule PaperTrailTest do
   @repo PaperTrail.RepoClient.repo
   @create_company_params %{name: "Acme LLC", is_active: true, city: "Greenwich"}
   @update_company_params %{city: "Hong Kong", website: "http://www.acme.com", facebook: "acme.llc"}
+  @create_company_with_people_params %{name: "Acme LLC", is_active: true, city: "Greenwich", people: [%{first_name: "Izel"}]}
 
   doctest PaperTrail
 
@@ -326,6 +327,45 @@ defmodule PaperTrailTest do
     assert person == first(Person, :id) |> @repo.one |> serialize
   end
 
+  test "updating a company with people changes creates a version with correct attributes" do
+   {:ok, %{model: company}} = create_company_with_people_with_version()
+   person_id = List.first(company.people).id
+   {:ok, result} = Company.people_changeset(company, %{
+     name: "Another Company",
+     people: [%{id: person_id, first_name: "abmm"}]
+   }) |> PaperTrail.update
+   company_count = Person.count()
+   version_count = Version.count()
+   company = result[:model] |> serialize
+   version = result[:version] |> serialize
+   assert Map.keys(result) == [:model, :version]
+   assert company_count == 1
+   assert version_count == 2
+   assert Map.drop(company, [:id, :inserted_at, :updated_at]) == %{
+     name: "Another Company",
+     address: nil,
+     city: "Greenwich",
+     twitter: nil,
+     facebook: nil,
+     founded_in: nil,
+     is_active: true,
+     website: nil
+   }
+   assert Map.drop(version, [:id, :inserted_at]) == %{
+     event: "update",
+     item_type: "SimpleCompany",
+     item_id: company.id,
+     item_changes: %{
+       name: "Another Company",
+       people: [%{ first_name: "abmm", id: person_id}]
+     },
+     originator_id: nil,
+     origin: nil,
+     meta: nil
+   }
+   assert company == first(Company, :id) |> @repo.one |> serialize
+  end
+
   test "deleting a person creates a person version with correct attributes" do
     create_company_with_version(%{name: "Acme LLC", website: "http://www.acme.com"})
     {:ok, target_company_insertion} = create_company_with_version(%{
@@ -391,6 +431,10 @@ defmodule PaperTrailTest do
     Company.changeset(company, params) |> PaperTrail.update(options)
   end
 
+  defp create_company_with_people_with_version(params \\ @create_company_with_people_params, options \\ nil) do
+    Company.people_changeset(%Company{}, params) |> PaperTrail.insert(options)
+  end
+
   defp serialize(model) do
     relationships = model.__struct__.__schema__(:associations)
     Map.drop(model, [:__struct__, :__meta__] ++ relationships)

test/support/simple_models.exs

@@ -30,6 +30,13 @@ defmodule SimpleCompany do
     |> no_assoc_constraint(:people)
   end
 
+  def people_changeset(model, params \\ %{}) do
+    model
+    |> cast(params, @optional_fields)
+    |> cast_assoc(:people)
+    |> validate_required([:name])
+  end
+
   def count do
     from(record in __MODULE__, select: count(record.id)) |> PaperTrail.RepoClient.repo.one
   end