defmodule AshPostgres.Repo do
@moduledoc """
Resources that use `AshPostgres.DataLayer` use a `Repo` to access the database.
This repo is a thin wrapper around an `Ecto.Repo`.
You can use `Ecto.Repo`'s `init/2` to configure your repo like normal, but
instead of returning `{:ok, config}`, use `super(config)` to pass the
configuration to the `AshPostgres.Repo` implementation.
## Installed Extensions
To configure your list of installed extensions, define `installed_extensions/0`
Extensions can be a string, representing a standard postgres extension, or a module that implements `AshPostgres.CustomExtension`.
That custom extension will be called to generate migrations that serve a specific purpose.
Extensions that are relevant to ash_postgres:
* "ash-functions" - This isn't really an extension, but it expresses that certain functions
should be added when generating migrations, to support the `||` and `&&` operators in expressions.
* `"uuid-ossp"` - Sets UUID primary keys defaults in the migration generator
* `"pg_trgm"` - Makes the `AshPostgres.Functions.TrigramSimilarity` function available
* "citext" - Allows case insensitive fields to be used
* `"vector"` - Makes the `AshPostgres.Functions.VectorCosineDistance` function available. See `AshPostgres.Extensions.Vector` for more setup instructions.
```
def installed_extensions() do
["pg_trgm", "uuid-ossp", "vector", YourCustomExtension]
end
```
## Transaction Hooks
You can define `on_transaction_begin/1`, which will be invoked whenever a transaction is started for Ash.
This will be invoked with a map containing a `type` key and metadata.
```elixir
%{type: :create, %{resource: YourApp.YourResource, action: :action}}
```
"""
@doc "Use this to inform the data layer about what extensions are installed"
@callback installed_extensions() :: [String.t() | module()]
@doc """
Use this to inform the data layer about the oldest potential postgres version it will be run on.
Must be an integer greater than or equal to 13.
## Combining with other tools
For things like `Fly.Repo`, where you might need to have more fine grained control over the repo module,
you can use the `define_ecto_repo?: false` option to `use AshPostgres.Repo`.
"""
@callback min_pg_version() :: integer()
@callback on_transaction_begin(reason :: Ash.DataLayer.transaction_reason()) :: term
@doc "Return a list of all schema names (only relevant for a multitenant implementation)"
@callback all_tenants() :: [String.t()]
@doc "The path where your tenant migrations are stored (only relevant for a multitenant implementation)"
@callback tenant_migrations_path() :: String.t() | nil
@doc "The path where your migrations are stored"
@callback migrations_path() :: String.t() | nil
@doc "The default prefix(postgres schema) to use when building queries"
@callback default_prefix() :: String.t()
@doc "Allows overriding a given migration type for *all* fields, for example if you wanted to always use :timestamptz for :utc_datetime fields"
@callback override_migration_type(atom) :: atom
defmacro __using__(opts) do
quote bind_quoted: [opts: opts] do
if Keyword.get(opts, :define_ecto_repo?, true) do
otp_app = opts[:otp_app] || raise("Must configure OTP app")
use Ecto.Repo,
adapter: Ecto.Adapters.Postgres,
otp_app: otp_app
end
@behaviour AshPostgres.Repo
defoverridable insert: 2, insert: 1, insert!: 2, insert!: 1
def installed_extensions, do: []
def tenant_migrations_path, do: nil
def migrations_path, do: nil
def default_prefix, do: "public"
def override_migration_type(type), do: type
def min_pg_version, do: 10
def transaction!(fun) do
case fun.() do
{:ok, value} -> value
{:error, error} -> raise Ash.Error.to_error_class(error)
end
end
def all_tenants do
raise """
`#{inspect(__MODULE__)}.all_tenants/0` was called, but was not defined. In order to migrate tenants, you must define this function.
For example, you might say:
def all_tenants do
for org <- MyApp.Accounts.all_organizations!() do
org.schema
end
end
"""
end
def init(_, config) do
new_config =
config
|> Keyword.put(:installed_extensions, installed_extensions())
|> Keyword.put(:tenant_migrations_path, tenant_migrations_path())
|> Keyword.put(:migrations_path, migrations_path())
|> Keyword.put(:default_prefix, default_prefix())
{:ok, new_config}
end
def on_transaction_begin(_reason), do: :ok
def insert(struct_or_changeset, opts \\ []) do
struct_or_changeset
|> to_ecto()
|> then(fn value ->
repo = get_dynamic_repo()
Ecto.Repo.Schema.insert(
__MODULE__,
repo,
value,
Ecto.Repo.Supervisor.tuplet(repo, prepare_opts(:insert, opts))
)
end)
|> from_ecto()
end
def insert!(struct_or_changeset, opts \\ []) do
struct_or_changeset
|> to_ecto()
|> then(fn value ->
repo = get_dynamic_repo()
Ecto.Repo.Schema.insert!(
__MODULE__,
repo,
value,
Ecto.Repo.Supervisor.tuplet(repo, prepare_opts(:insert, opts))
)
end)
|> from_ecto()
end
def from_ecto({:ok, result}), do: {:ok, from_ecto(result)}
def from_ecto({:error, _} = other), do: other
def from_ecto(nil), do: nil
def from_ecto(value) when is_list(value) do
Enum.map(value, &from_ecto/1)
end
def from_ecto(%resource{} = record) do
if Spark.Dsl.is?(resource, Ash.Resource) do
empty = struct(resource)
resource
|> Ash.Resource.Info.relationships()
|> Enum.reduce(record, fn relationship, record ->
case Map.get(record, relationship.name) do
%Ecto.Association.NotLoaded{} ->
Map.put(record, relationship.name, Map.get(empty, relationship.name))
value ->
Map.put(record, relationship.name, from_ecto(value))
end
end)
else
record
end
end
def from_ecto(other), do: other
def to_ecto(nil), do: nil
def to_ecto(value) when is_list(value) do
Enum.map(value, &to_ecto/1)
end
def to_ecto(%resource{} = record) do
if Spark.Dsl.is?(resource, Ash.Resource) do
resource
|> Ash.Resource.Info.relationships()
|> Enum.reduce(record, fn relationship, record ->
value =
case Map.get(record, relationship.name) do
%Ash.NotLoaded{} ->
%Ecto.Association.NotLoaded{
__field__: relationship.name,
__cardinality__: relationship.cardinality
}
value ->
to_ecto(value)
end
Map.put(record, relationship.name, value)
end)
else
record
end
end
def to_ecto(other), do: other
defoverridable init: 2,
on_transaction_begin: 1,
installed_extensions: 0,
all_tenants: 0,
tenant_migrations_path: 0,
default_prefix: 0,
override_migration_type: 1,
min_pg_version: 0
end
end
end
