nullable maps with nested models

Author: efcasado

modules/openapi-generator/src/main/resources/elixir/ecto_utils.ex.mustache

@@ -1,29 +1,33 @@
 {{>licenseInfo}}
 defmodule {{moduleName}}.EctoUtils do
   def cast_nested_map(changeset, field, schema) do
-    values = Map.get(changeset.changes, field) || %{}
+    case Map.get(changeset.changes, field) do
+      nil ->
+        changeset
 
-    {result_map, errors} =
-      Enum.reduce(values, {%{}, []}, fn {key, params}, {acc, errs} ->
-        changeset = schema.changeset(struct(schema), params)
+      values ->
+        {result_map, errors} =
+          Enum.reduce(values, {%{}, []}, fn {key, params}, {acc, errs} ->
+            changeset = schema.changeset(struct(schema), params)
 
-        case Ecto.Changeset.apply_action(changeset, changeset.action || :insert) do
-          {:ok, struct} ->
-            {Map.put(acc, key, struct), errs}
+            case Ecto.Changeset.apply_action(changeset, changeset.action || :insert) do
+              {:ok, struct} ->
+                {Map.put(acc, key, struct), errs}
 
-          {:error, nested_cs} ->
-            {Map.put(acc, key, nested_cs), [{key, nested_cs} | errs]}
-        end
-      end)
+              {:error, nested_cs} ->
+                {Map.put(acc, key, nested_cs), [{key, nested_cs} | errs]}
+            end
+          end)
 
-    changeset =
-      Ecto.Changeset.put_change(changeset, field, result_map)
+        changeset =
+          Ecto.Changeset.put_change(changeset, field, result_map)
 
-    if errors == [] do
-      changeset
-    else
-      Ecto.Changeset.add_error(changeset, field, "contains invalid nested entries")
-      |> Map.put(:valid?, false)
+        if errors == [] do
+          changeset
+        else
+          Ecto.Changeset.add_error(changeset, field, "contains invalid nested entries")
+          |> Map.put(:valid?, false)
+        end
     end
   end
 end

samples/client/petstore/elixir/lib/openapi_petstore/ecto_utils.ex

@@ -3,29 +3,33 @@
 
 defmodule OpenapiPetstore.EctoUtils do
   def cast_nested_map(changeset, field, schema) do
-    values = Map.get(changeset.changes, field) || %{}
+    case Map.get(changeset.changes, field) do
+      nil ->
+        changeset
 
-    {result_map, errors} =
-      Enum.reduce(values, {%{}, []}, fn {key, params}, {acc, errs} ->
-        changeset = schema.changeset(struct(schema), params)
+      values ->
+        {result_map, errors} =
+          Enum.reduce(values, {%{}, []}, fn {key, params}, {acc, errs} ->
+            changeset = schema.changeset(struct(schema), params)
 
-        case Ecto.Changeset.apply_action(changeset, changeset.action || :insert) do
-          {:ok, struct} ->
-            {Map.put(acc, key, struct), errs}
+            case Ecto.Changeset.apply_action(changeset, changeset.action || :insert) do
+              {:ok, struct} ->
+                {Map.put(acc, key, struct), errs}
 
-          {:error, nested_cs} ->
-            {Map.put(acc, key, nested_cs), [{key, nested_cs} | errs]}
-        end
-      end)
+              {:error, nested_cs} ->
+                {Map.put(acc, key, nested_cs), [{key, nested_cs} | errs]}
+            end
+          end)
 
-    changeset =
-      Ecto.Changeset.put_change(changeset, field, result_map)
+        changeset =
+          Ecto.Changeset.put_change(changeset, field, result_map)
 
-    if errors == [] do
-      changeset
-    else
-      Ecto.Changeset.add_error(changeset, field, "contains invalid nested entries")
-      |> Map.put(:valid?, false)
+        if errors == [] do
+          changeset
+        else
+          Ecto.Changeset.add_error(changeset, field, "contains invalid nested entries")
+          |> Map.put(:valid?, false)
+        end
     end
   end
 end