To create a Customer resource using the Ash DSL and the Ash framework in an Elixir application with PostgreSQL as the data layer, you'll need to follow these steps. I'll break down each step and provide code examples as needed.
Make sure you have Elixir and PostgreSQL installed on your system. Then, create a new Elixir project using Mix:
mix new your_customer_app
cd your_customer_app
Add the required dependencies to your mix.exs
file:
defp deps do
[
{:ash, "~> 0.3"},
{:ash_postgres, "~> 0.3"},
{:ash_graphql, "~> 0.3"},
{:ecto_sql, "~> 3.7"},
{:absinthe, "~> 1.6"},
{:absinthe_plug, "~> 1.6"},
# Add other dependencies as needed
]
end
Now, fetch the dependencies:
mix deps.get
Create a new Ash resource for the Customer entity. In your project's lib/your_customer_app/resources
directory, create a file named customer_resource.ex
:
defmodule YourCustomerApp.Resources.CustomerResource do
use Ash.Resource
attributes do
field :first_name, :string
field :last_name, :string
field :email, :string
validate_length(:first_name, min: 2, max: 50)
validate_length(:last_name, min: 2, max: 50)
validate_format(:email, ~r/^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/, message: "Invalid email format")
validate_unique(:email)
end
data_layer Ash.Postgres.DataLayer
actions do
create
update
delete
end
api do
actions([:create, :update, :delete])
end
graphql do
type YourCustomerApp.GraphQL.Types.CustomerType
end
end
Generate an Ecto migration for the Customer table:
mix ecto.gen.migration create_customers
Open the generated migration file in priv/repo/migrations
and define the up
and down
functions to create and drop the customers
table with the required fields.
defmodule YourCustomerApp.Repo.Migrations.CreateCustomers do
use Ecto.Migration
def up do
create table(:customers) do
add :first_name, :string
add :last_name, :string
add :email, :string, unique: true
timestamps()
end
create(unique_index(:customers, [:email]))
end
def down do
drop table(:customers)
end
end
Run the migration:
mix ecto.migrate
In your application's configuration (config/config.exs
), add the Ash configuration:
config :your_customer_app, YourCustomerApp.Ash.Repo,
data_layer: Ash.Postgres.DataLayer
Now, configure GraphQL in the same file:
config :your_customer_app, YourCustomerAppWeb.Schema,
# ...
:modules, [YourCustomerAppWeb.Schema.Types.CustomerType]
Define a GraphQL type for the Customer in lib/your_customer_app_web/schema/types/customer_type.ex
:
defmodule YourCustomerAppWeb.Schema.Types.CustomerType do
use Absinthe.Schema.Notation
alias YourCustomerApp.Resources.CustomerResource
object do
field :id, :id
field :first_name, :string
field :last_name, :string
field :email, :string
interfaces([Ash.GraphQL.Interfaces.Node])
end
end
In your GraphQL schema file (lib/your_customer_app_web/schema.ex
), define the queries and mutations for Customer:
defmodule YourCustomerAppWeb.Schema do
use Absinthe.Schema
alias YourCustomerApp.Resources.CustomerResource
query do
field :customer, CustomerResource.get_action(:read)
end
mutation do
field :create_customer, CustomerResource.get_action(:create)
field :update_customer, CustomerResource.get_action(:update)
field :delete_customer, CustomerResource.get_action(:delete)
end
# ...
end
You should now have a Customer resource configured with Ash, Ecto, and GraphQL. To run your application:
mix phx.server
You can use GraphQL queries and mutations to interact with the Customer resource using your API. Make sure to replace YourCustomerApp
with your actual application module names and adjust the code accordingly for your project structure.