EctoNestedChangeset

This is a package for manipulating nested Ecto changesets.

Installation

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

def deps do
  [
    {:ecto_nested_changeset, "~> 1.0.0"}
  ]
end

Usage

The primary use case of this library is the manipulation of Ecto changesets used as a source for dynamic, nested forms in Phoenix LiveView.

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.

git clone https://github.com/woylie/ecto_nested_changeset.git
cd ecto_nested_changeset/example
mix setup
mix phx.server

Note that Postgres needs to be running to use the application.

You can access the application at http://localhost:4000.

Status

This library is actively maintained, but given its narrow purpose, it will not see frequent updates.