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# EctoNestedChangeset

This is an experimental package for manipulating nested Ecto changesets.

## Installation

Add `ecto_nested_changeset` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:ecto_nested_changeset, "~> 0.1.2"}
  ]
end
```

See the module documentation of `EctoNestedChangeset` for usage examples.

## Usage

```elixir
category = %Category{
  posts: [
    %Post{
      id: 1,
      comments: [
        %Comment{body: "potato", id: 1},
        %Comment{body: "you", id: 2}
      ],
      title: "must"
    },
    %Post{comments: [], id: 2, title: "young"}
  ]
}

category
|> Ecto.Changeset.change()
|> append_at(:posts, %Post{title: "Padawan", comments: []})
|> prepend_at([:posts, 0, :comments], %Comment{body: "ecneitaP"})
|> delete_at([:posts, 0, :comments, 1], mode: {:action, :delete})
|> insert_at([:posts, 1], %Post{title: "have"})
|> append_at([:posts, 2, :comments], %Comment{body: "my"})
|> update_at([:posts, 0, :comments, 0, :body], &String.reverse/1)
|> Ecto.Changeset.apply_changes()

%Category{
  posts: [
    %Post{
      comments: [
        %Comment{body: "Patience"},
        %Comment{body: "you", id: 2}
      ],
      id: 1,
      title: "must"
    },
    %Post{title: "have"},
    %Post{
      comments: [%Comment{body: "my"}],
      id: 2,
      title: "young"
    },
    %Post{title: "Padawan"}
  ]
}
```

## Example application

There is an example Phoenix application with a dynamic nested LiveView form in
the `/example` folder of the repository.

```bash
cd example
mix setup
mix phx.server
```

You can access the list of pet owners at http://localhost:4000.