Programming Phoenix

Building Forms

Now that we have a database-backed repository, let’s add the ability to create new users in our system. We’re going to use Phoenix’s form builders for that purpose. First, open up your controller at web/controllers/user_controller.ex and set up a new user record for our new template, like this:

ecto/listings/rumbl/web/controllers/user_controller.change1.ex

alias Rumbl.User

def new(conn, _params) do
  changeset = User.changeset(%User{})
  render conn, "new.html", changeset: changeset
end

Notice the User.changeset function. This function receives a struct and the controller parameter, and returns an Ecto.Changeset. Changesets let Ecto manage record changes, cast parameters, and perform validations. We use a changeset ...