From 9a870edf983cd95dc2d3fe4b5ca1fd904830fde4 Mon Sep 17 00:00:00 2001
From: James Gough <james@peacefulprogramming.dev>
Date: Sat, 3 May 2025 18:05:11 +0100
Subject: [PATCH 1/3] test it

---
 test/polymorphic_embed_test.exs | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/test/polymorphic_embed_test.exs b/test/polymorphic_embed_test.exs
index 7dced00..8844431 100644
--- a/test/polymorphic_embed_test.exs
+++ b/test/polymorphic_embed_test.exs
@@ -2598,6 +2598,35 @@ defmodule PolymorphicEmbedTest do
       assert [input] = Floki.find(html, "#reminder_channel2_0_number")
       assert Floki.attribute(input, "type") == ["text"]
     end
+
+    test "uses default value if value is nil" do
+      reminder_module = get_module(Reminder, :polymorphic)
+
+      attrs = %{
+        date: ~U[2020-05-28 02:57:19Z],
+        text: "This is an Email reminder",
+        channel2: nil
+      }
+
+      changeset =
+        reminder_module
+        |> struct()
+        |> reminder_module.changeset(attrs)
+
+      html =
+        render_component(
+          &liveview_form_component/1,
+          %{changeset: changeset, field: :channel2}
+        )
+        |> Floki.parse_fragment!()
+
+      assert [input] = Floki.find(html, ~s([name="reminder[channel2][__type__]"]))
+      assert Floki.attribute(input, "type") == ["hidden"]
+      assert Floki.attribute(input, "value") == ["sms"]
+
+      assert [input] = Floki.find(html, "#reminder_channel2_0_number")
+      assert Floki.attribute(input, "type") == ["text"]
+    end
   end
 
   describe "polymorphic_embed_inputs_for/2" do
@@ -3513,7 +3542,7 @@ defmodule PolymorphicEmbedTest do
       :let={f}
       for={@changeset}
     >
-      <.polymorphic_embed_inputs_for field={f[@field]} :let={sms_form}>
+      <.polymorphic_embed_inputs_for field={f[@field]} :let={sms_form} default={%PolymorphicEmbed.Channel.SMS{}}>
         <%= text_input sms_form, :number %>
       </.polymorphic_embed_inputs_for>
     </.form>

From ddc2768d3cf6d929a062ebd6c4b62449d185a505 Mon Sep 17 00:00:00 2001
From: James Gough <james@peacefulprogramming.dev>
Date: Sat, 3 May 2025 18:05:24 +0100
Subject: [PATCH 2/3] fix it

---
 lib/polymorphic_embed/html/helpers.ex | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/polymorphic_embed/html/helpers.ex b/lib/polymorphic_embed/html/helpers.ex
index 7822d46..1091a55 100644
--- a/lib/polymorphic_embed/html/helpers.ex
+++ b/lib/polymorphic_embed/html/helpers.ex
@@ -62,7 +62,12 @@ if Code.ensure_loaded?(Phoenix.HTML) && Code.ensure_loaded?(Phoenix.HTML.Form) d
           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: []
+
+            cond do
+              module -> [struct(module)]
+              options[:default] -> [options[:default]]
+              true -> []
+            end
 
           data ->
             List.wrap(data)

From 8ddf0b36d23ff6305e77f028fe232a7fa892860b Mon Sep 17 00:00:00 2001
From: Andrea Leopardi <an.leopardi@gmail.com>
Date: Tue, 6 May 2025 14:26:55 +0200
Subject: [PATCH 3/3] Update lib/polymorphic_embed/html/helpers.ex

---
 lib/polymorphic_embed/html/helpers.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/polymorphic_embed/html/helpers.ex b/lib/polymorphic_embed/html/helpers.ex
index 1091a55..433a73a 100644
--- a/lib/polymorphic_embed/html/helpers.ex
+++ b/lib/polymorphic_embed/html/helpers.ex
@@ -65,7 +65,7 @@ if Code.ensure_loaded?(Phoenix.HTML) && Code.ensure_loaded?(Phoenix.HTML.Form) d
 
             cond do
               module -> [struct(module)]
-              options[:default] -> [options[:default]]
+              default = options[:default] -> [default]
               true -> []
             end