add tree node function

lib/radiator/outline.ex

@@ -64,23 +64,37 @@ defmodule Radiator.Outline do
 
  @doc """
  Gets all nodes of an episode as a tree.
+ Uses a Common Table Expression (CTE) to recursively query the database.
 
  ## Examples
 
  iex> get_node_tree(123)
  [%Node{}, %Node{}, ..]
  """
  def get_node_tree(episode_id) do
-
  node_tree_initial_query =
  Node
  |> where([n], is_nil(n.parent_id))
  |> where([n], n.episode_id == ^episode_id)
- |> select([n], %{uuid: n.uuid, content: n.content, parent_id: n.parent_id, prev_id: n.prev_id, level: 0})
-
- node_tree_recursion_query = from outline_node in "outline_nodes",
- join: node_tree in "node_tree", on: outline_node.parent_id == node_tree.uuid,
- select: [outline_node.uuid, outline_node.content, outline_node.parent_id, outline_node.prev_id, node_tree.level + 1]
+ |> select([n], %{
+ uuid: n.uuid,
+ content: n.content,
+ parent_id: n.parent_id,
+ prev_id: n.prev_id,
+ level: 0
+ })
+
+ node_tree_recursion_query =
+ from outline_node in "outline_nodes",
+ join: node_tree in "node_tree",
+ on: outline_node.parent_id == node_tree.uuid,
+ select: [
+ outline_node.uuid,
+ outline_node.content,
+ outline_node.parent_id,
+ outline_node.prev_id,
+ node_tree.level + 1
+ ]
 
  node_tree_query =
  node_tree_initial_query
@@ -90,17 +104,30 @@ defmodule Radiator.Outline do
  "node_tree"
  |> recursive_ctes(true)
  |> with_cte("node_tree", as: ^node_tree_query)
- |> select([n], %{uuid: n.uuid, content: n.content, parent_id: n.parent_id, prev_id: n.prev_id, level: n.level})
+ |> select([n], %{
+ uuid: n.uuid,
+ content: n.content,
+ parent_id: n.parent_id,
+ prev_id: n.prev_id,
+ level: n.level
+ })
  |> Repo.all()
- |> Enum.map(fn %{uuid: uuid, content: content, parent_id: parent_id, prev_id: prev_id, level: level} ->
+ |> Enum.map(fn %{
+ uuid: uuid,
+ content: content,
+ parent_id: parent_id,
+ prev_id: prev_id,
+ level: level
+ } ->
  %Node{
  uuid: binaray_uuid_to_ecto_uuid(uuid),
  content: content,
- parent_id:  binaray_uuid_to_ecto_uuid(parent_id),
- prev_id:  binaray_uuid_to_ecto_uuid(prev_id),
+ parent_id: binaray_uuid_to_ecto_uuid(parent_id),
+ prev_id: binaray_uuid_to_ecto_uuid(prev_id),
  level: level
  }
  end)
+
  {:ok, tree}
  end
 
@@ -175,6 +202,7 @@ defmodule Radiator.Outline do
  defp broadcast_node_action({:error, error}, _action), do: {:error, error}
 
  defp binaray_uuid_to_ecto_uuid(nil), do: nil
+
  defp binaray_uuid_to_ecto_uuid(uuid) do
  Ecto.UUID.load!(uuid)
  end

priv/repo/seeds.exs

@@ -61,6 +61,5 @@ alias Radiator.{Accounts, Outline, Podcast}
  prev_id: node211.uuid
  })
 
-
- {:ok, past_parent_node} =
- Outline.create_node(%{content: "Old Content", episode_id: past_episode.id})
+{:ok, past_parent_node} =
+ Outline.create_node(%{content: "Old Content", episode_id: past_episode.id})

test/radiator/outline_test.exs

@@ -92,14 +92,17 @@ defmodule Radiator.OutlineTest do
  Node
  |> where([n], n.episode_id == ^episode_id)
  |> Repo.all()
+
  assert Enum.count(tree) == Enum.count(all_nodes)
+
  Enum.each(tree, fn node ->
- assert node.uuid == List.first(Enum.filter(all_nodes, fn n -> n.uuid == node.uuid end)).uuid
+ assert node.uuid ==
+ List.first(Enum.filter(all_nodes, fn n -> n.uuid == node.uuid end)).uuid
  end)
  end
 
  test "does not return a node not in this episode", %{
- parent: parent
+  parent: parent
  } do
  episode_id = parent.episode_id
  other_node = node_fixture(parent_id: nil, prev_id: nil, content: "other content")
@@ -120,7 +123,9 @@ defmodule Radiator.OutlineTest do
  node_6 = node_fixture(episode_id: episode.id, parent_id: parent.uuid, prev_id: node_5.uuid)
 
  nested_node_1 = node_fixture(episode_id: episode.id, parent_id: node_3.uuid, prev_id: nil)
- nested_node_2 = node_fixture(episode_id: episode.id, parent_id: node_3.uuid, prev_id: nested_node_1.uuid)
+
+ nested_node_2 =
+ node_fixture(episode_id: episode.id, parent_id: node_3.uuid, prev_id: nested_node_1.uuid)
 
  %{
  node_1: node_1,