Handle DateTime fields through Repo

lib/dlex/node.ex

@@ -238,7 +238,7 @@ defmodule Dlex.Node do
     float: "float",
     string: "string",
     geo: "geo",
-    datetime: "datetime",
+    utc_datetime: "datetime",
     uid: "[uid]"
   ]
 

lib/dlex/repo.ex

@@ -138,6 +138,7 @@ defmodule Dlex.Repo do
     end
   end
 
+  def encode(%DateTime{} = data), do: data
   def encode(%{__struct__: struct} = data) do
     data
     |> Map.from_struct()
@@ -148,6 +149,7 @@ defmodule Dlex.Repo do
   def encode(data) when is_list(data), do: encode_list(data, [])
   def encode(data), do: data
 
+
   defp encode_kv([], map, _struct), do: map
   defp encode_kv([{_key, nil} | kv], map, struct), do: encode_kv(kv, map, struct)
 
@@ -227,6 +229,8 @@ defmodule Dlex.Repo do
     with %{} = map <- do_decode(map, lookup, strict?), do: {:ok, map}
   end
 
+
+
   defp do_decode(map, lookup, strict?) when is_map(map) and is_map(lookup) do
     with %{"dgraph.type" => [type_string]} <- map,
          type when type != nil <- Map.get(lookup, type_string) do
@@ -264,6 +268,11 @@ defmodule Dlex.Repo do
     end)
   end
 
+  defp do_decode_field(struct, {field_name, :utc_datetime}, value, lookup, strict?) when not is_struct(value) do
+    {:ok, new_value} = Calendar.DateTime.Parse.rfc3339_utc(value)
+    do_decode_field(struct, {field_name, :utc_datetime}, new_value, lookup, strict?)
+  end
+
   defp do_decode_field(struct, {field_name, field_type}, value, lookup, strict?) do
     case Ecto.Type.load(field_type, value) do
       {:ok, loaded_value} ->

mix.exs

@@ -30,6 +30,7 @@ defmodule Dlex.MixProject do
     [
       {:db_connection, "~> 2.1"},
       {:grpc, "~> 0.3.1"},
+      {:calendar, "~> 1.0.0"},
       {:jason, "~> 1.0", optional: true},
       {:mint, "~> 1.0", optional: true},
       {:castore, "~> 0.1.4", optional: true},

test/dlex/node_test.exs

@@ -8,7 +8,7 @@ defmodule Dlex.NodeTest do
       assert "user" == User.__schema__(:source)
       assert :string == User.__schema__(:type, :name)
       assert :integer == User.__schema__(:type, :age)
-      assert [:name, :age, :friends, :location] == User.__schema__(:fields)
+      assert [:name, :age, :friends, :location, :modified] == User.__schema__(:fields)
     end
 
     test "alter" do
@@ -22,11 +22,13 @@ defmodule Dlex.NodeTest do
                  },
                  %{"predicate" => "user.age", "type" => "int"},
                  %{"predicate" => "user.friends", "type" => "[uid]"},
-                 %{"predicate" => "user.location", "type" => "geo"}
+                 %{"predicate" => "user.location", "type" => "geo"},
+                 %{"predicate" => "user.modified", "type" => "datetime"}
                ],
                "types" => [
                  %{
                    "fields" => [
+                     %{"name" => "user.modified", "type" => "datetime"},
                      %{"name" => "user.location", "type" => "geo"},
                      %{"name" => "user.friends", "type" => "[uid]"},
                      %{"name" => "user.age", "type" => "int"},

test/dlex/repo_test.exs

@@ -36,6 +36,14 @@ defmodule Dlex.RepoTest do
       assert {:ok, %{uid: _uid}} = TestRepo.set(valid_changeset)
     end
 
+    test "setting datetime field in Changeset" do
+      now = DateTime.utc_now()
+      changeset = Ecto.Changeset.cast(%User{}, %{name: "TimeTraveler", age: 20, modified: now}, [:name, :age, :modified])
+      assert {:ok, %{uid: uid}} = TestRepo.set(changeset)
+
+      assert {:ok, %User{name: "TimeTraveler", age: 20, modified: now}} = TestRepo.get(uid)
+    end
+
     test "using custom types" do
       changes = %{name: "John", age: 30, location: %{lat: 15.5, lon: 10.2}}
       changeset = Changeset.cast(%User{}, changes, [:name, :age, :location])

test/test_helper.exs

@@ -48,6 +48,7 @@ defmodule Dlex.User do
     field :age, :integer
     field :friends, :uid
     field :location, Dlex.Geo
+    field :modified, :utc_datetime
     field :cache, :any, virtual: true
   end
 end