go for source_changeset.changes first, fallback to struct field

Author: nduitz

lib/polymorphic_embed/html/helpers.ex

@@ -57,46 +57,70 @@ if Code.ensure_loaded?(Phoenix.HTML) && Code.ensure_loaded?(Phoenix.HTML.Form) d
 
       struct = Ecto.Changeset.apply_changes(source_changeset)
 
-      list_data =
-        case Map.get(struct, field) do
-          nil ->
-            type = Keyword.get(options, :polymorphic_type, get_polymorphic_type(form, field))
-            module = PolymorphicEmbed.get_polymorphic_module(struct.__struct__, field, type)
-            if module, do: [struct(module)], else: []
-
-          data ->
-            List.wrap(data)
-        end
-
-      list_data
-      |> Enum.with_index()
-      |> Enum.map(fn {data, i} ->
-        params =
-          case params do
+      Map.get(source_changeset.changes, field)
+      |> case do
+        nil ->
+          case Map.get(struct, field) do
             nil ->
-              %{}
-
-            params when is_list(params) ->
-              Enum.at(params, i) || %{}
+              type = Keyword.get(options, :polymorphic_type, get_polymorphic_type(form, field))
+              module = PolymorphicEmbed.get_polymorphic_module(struct.__struct__, field, type)
+              if module, do: [struct(module)], else: []
 
-            params when is_map(params) ->
-              Map.get(params, to_string(i), %{})
+            data ->
+              List.wrap(data)
           end
 
-        changeset =
+        data when is_list(data) ->
           data
-          |> Ecto.Changeset.change()
-          |> apply_action(parent_action)
 
-        errors = get_errors(changeset)
-
-        changeset = %Ecto.Changeset{
-          changeset
-          | action: parent_action,
-            params: params,
-            errors: errors,
-            valid?: errors == []
-        }
+        data ->
+          List.wrap(data)
+      end
+      |> Enum.with_index()
+      |> Enum.map(fn
+        {%Ecto.Changeset{} = changeset, i} ->
+          params = changeset.params || %{}
+          errors = get_errors(changeset)
+
+          %{changeset: changeset, params: params, errors: errors, index: i}
+
+        {data, i} ->
+          params =
+            case params do
+              nil ->
+                %{}
+
+              params when is_list(params) ->
+                Enum.at(params, i) || %{}
+
+              params when is_map(params) ->
+                Map.get(params, to_string(i), %{})
+            end
+
+          changeset =
+            data
+            |> Ecto.Changeset.change()
+            |> apply_action(parent_action)
+
+          errors = get_errors(changeset)
+
+          changeset = %{
+            changeset
+            | action: parent_action,
+              params: params,
+              errors: errors,
+              valid?: errors == []
+          }
+
+          %{changeset: changeset, params: params, errors: errors, index: i}
+      end)
+      |> Enum.map(fn prepared_data ->
+        %{
+          changeset: changeset,
+          params: params,
+          errors: errors,
+          index: i
+        } = prepared_data
 
         %schema{} = source_changeset.data
 
@@ -116,7 +140,8 @@ if Code.ensure_loaded?(Phoenix.HTML) && Code.ensure_loaded?(Phoenix.HTML.Form) d
           name: if(array?, do: name <> "[" <> index_string <> "]", else: name),
           index: if(array?, do: i),
           errors: errors,
-          data: data,
+          data: changeset.data,
+          action: parent_action,
           params: params,
           hidden: [{type_field_name, to_string(type)}],
           options: options

test/polymorphic_embed_test.exs

@@ -2704,15 +2704,26 @@ defmodule PolymorphicEmbedTest do
     for generator <- @generators do
       reminder_module = get_module(Reminder, generator)
 
-      attrs = %{
-        date: ~U[2020-05-28 02:57:19Z],
-        text: "This is an Email reminder",
-        channel: %{
-          address: "a",
-          valid: true,
-          confirmed: true
-        }
-      }
+      attrs =
+        if polymorphic?(generator) do
+          %{
+            date: ~U[2020-05-28 02:57:19Z],
+            text: "This is an Email reminder",
+            channel: %{
+              address: "a",
+              valid: true,
+              confirmed: true
+            }
+          }
+        else
+          %{
+            number: ~U[2020-05-28 02:57:19Z],
+            text: "This is a non polymorphic reminder",
+            channel: %{
+              number: "a"
+            }
+          }
+        end
 
       changeset =
         struct(reminder_module)
@@ -2721,8 +2732,19 @@ defmodule PolymorphicEmbedTest do
       contents =
         safe_inputs_for(changeset, :channel, generator, fn f ->
           assert f.impl == Phoenix.HTML.FormData.Ecto.Changeset
-          assert f.errors == []
-          text_input(f, :address)
+
+          if polymorphic?(generator) do
+            assert f.errors == [
+                     {:address,
+                      {"should be at least %{count} character(s)",
+                       [count: 3, validation: :length, kind: :min, type: :string]}}
+                   ]
+
+            text_input(f, :address)
+          else
+            assert f.errors == []
+            text_input(f, :number)
+          end
         end)
 
       expected_contents =
@@ -2732,7 +2754,7 @@ defmodule PolymorphicEmbedTest do
           <input id="reminder_channel_address" name="reminder[channel][address]" type="text" value="a">
           """,
           else: ~s"""
-          <input id="reminder_channel_address" name="reminder[channel][address]" type="text" value="a">
+          <input id="reminder_channel_number" name="reminder[channel][number]" type="text" value="a">
           """
         )
 
@@ -2745,7 +2767,12 @@ defmodule PolymorphicEmbedTest do
           generator,
           fn f ->
             assert f.impl == Phoenix.HTML.FormData.Ecto.Changeset
-            text_input(f, :address)
+
+            if polymorphic?(generator) do
+              text_input(f, :address)
+            else
+              text_input(f, :number)
+            end
           end
         )
 
@@ -2756,7 +2783,7 @@ defmodule PolymorphicEmbedTest do
           <input id="reminder_channel_address" name="reminder[channel][address]" type="text" value="a">
           """,
           else: ~s"""
-          <input id="reminder_channel_address" name="reminder[channel][address]" type="text" value="a">
+          <input id="reminder_channel_number" name="reminder[channel][number]" type="text" value="a">
           """
         )