Programming Phoenix LiveView - Chapter 5

Using Ecto changesets without Ecto data

Note: This Livebook assumes it’s connected to an iex session for the Pento project from the book.

defmodule Player do
  defstruct [:username, :age]
end

player = %Player{}

We have a struct, easy peasy. But now how do we make it so that a changeset can work with that data? We need to describe the types of data in the struct.

With Ecto-backed data we could depend on the database schema to provide that data. But with a struct primitive we need to provide that type data primitively as well.

According to the docs for Ecto.Changeset.cast/4: data (the first argument) may be either a changeset, a schema struct or a {data, types} tuple

types = %{username: :string, age: :integer}

attrs = %{username: "player1", age: 40}

changeset =
  {player, types}
  |> Ecto.Changeset.cast(attrs, [:username, :age])
  |> Ecto.Changeset.validate_number(:age, greater_than: 18)

Promo

recipient = %Pento.Promo.Recipient{}
attrs = %{first_name: "Stephen", email: "sdballgmail.com"}

changeset = Pento.Promo.Recipient.changeset(recipient, attrs)

changeset.changes.email

Live Uploads

:code.priv_dir(:pento)

Path.join([:code.priv_dir(:pento), "static", "images"])

Search

sku_search = %Pento.Search.Sku{}
attrs = %{sku: "1234567"}
changeset = Pento.Search.build_search(sku_search, attrs)

product = Pento.Repo.get_by(Pento.Catalog.Product, sku: "1234567")

Pento.Catalog.get_product_by_sku!("1234567")