defmodule Spark.Dsl do
@using_schema [
single_extension_kinds: [
type: {:list, :atom},
default: [],
doc:
"The extension kinds that are allowed to have a single value. For example: `[:data_layer]`"
],
many_extension_kinds: [
type: {:list, :atom},
default: [],
doc:
"The extension kinds that can have multiple values. e.g `[notifiers: [Notifier1, Notifier2]]`"
],
untyped_extensions?: [
type: :boolean,
default: true,
doc: "Whether or not to support an `extensions` key which contains untyped extensions"
],
default_extensions: [
type: :keyword_list,
default: [],
doc: """
The extensions that are included by default. e.g `[data_layer: Default, notifiers: [Notifier1]]`
Default values for single extension kinds are overwritten if specified by the implementor, while many extension
kinds are appended to if specified by the implementor.
"""
]
]
@type entity :: %Spark.Dsl.Entity{}
@type section :: %Spark.Dsl.Section{}
@moduledoc """
The primary entry point for adding a DSL to a module.
To add a DSL to a module, add `use Spark.Dsl, ...options`. The options supported with `use Spark.Dsl` are:
#{Spark.OptionsHelpers.docs(@using_schema)}
See the callbacks defined in this module to augment the behavior/compilation of the module getting a Dsl.
## Schemas/Data Types
Spark DSLs use a superset of `NimbleOptions` for the `schema` that makes up sections/entities of the DSL.
For more information, see `Spark.OptionsHelpers`.
"""
@type opts :: Keyword.t()
@type t :: map()
@doc """
Validate/add options. Those options will be passed to `handle_opts` and `handle_before_compile`
"""
@callback init(opts) :: {:ok, opts} | {:error, String.t() | term}
@doc """
Handle options in the context of the module. Must return a `quote` block.
If you want to persist anything in the DSL persistence layer,
use `@persist {:key, value}`. It can be called multiple times to
persist multiple times.
"""
@callback handle_opts(Keyword.t()) :: Macro.t()
@doc """
Handle options in the context of the module, after all extensions have been processed. Must return a `quote` block.
"""
@callback handle_before_compile(Keyword.t()) :: Macro.t()
defmacro __using__(opts) do
opts = Spark.OptionsHelpers.validate!(opts, @using_schema)
their_opt_schema =
Enum.map(opts[:single_extension_kinds], fn extension_kind ->
{extension_kind, type: :atom, default: opts[:default_extensions][extension_kind]}
end) ++
Enum.map(opts[:many_extension_kinds], fn extension_kind ->
{extension_kind, type: {:list, :atom}, default: []}
end)
their_opt_schema =
if opts[:untyped_extensions?] do
Keyword.put(their_opt_schema, :extensions, type: {:list, :atom})
else
their_opt_schema
end
their_opt_schema = Keyword.put(their_opt_schema, :otp_app, type: :atom)
quote bind_quoted: [
their_opt_schema: their_opt_schema,
parent_opts: opts,
parent: __CALLER__.module
],
generated: true do
require Spark.Dsl.Extension
@dialyzer {:nowarn_function, handle_opts: 1, handle_before_compile: 1}
Module.register_attribute(__MODULE__, :spark_dsl, persist: true)
Module.register_attribute(__MODULE__, :spark_default_extensions, persist: true)
Module.register_attribute(__MODULE__, :spark_extension_kinds, persist: true)
@spark_dsl true
@spark_default_extensions parent_opts[:default_extensions]
|> Keyword.values()
|> List.flatten()
@spark_extension_kinds List.wrap(parent_opts[:many_extension_kinds]) ++
List.wrap(parent_opts[:single_extension_kinds])
def init(opts), do: {:ok, opts}
def default_extensions, do: @spark_default_extensions
def handle_opts(opts) do
quote do
end
end
def handle_before_compile(opts) do
quote do
end
end
defoverridable init: 1, handle_opts: 1, handle_before_compile: 1
defmacro __using__(opts) do
parent = unquote(parent)
parent_opts = unquote(parent_opts)
their_opt_schema = unquote(their_opt_schema)
require Spark.Dsl.Extension
{opts, extensions} =
parent_opts[:default_extensions]
|> Enum.reduce(opts, fn {key, defaults}, opts ->
Keyword.update(opts, key, defaults, fn current_value ->
cond do
key in parent_opts[:single_extension_kinds] ->
current_value || defaults
key in parent_opts[:many_extension_kinds] || key == :extensions ->
List.wrap(current_value) ++ List.wrap(defaults)
true ->
current_value
end
end)
end)
|> Spark.Dsl.expand_modules(parent_opts, __CALLER__)
opts =
opts
|> Spark.OptionsHelpers.validate!(their_opt_schema)
|> init()
|> Spark.Dsl.unwrap()
body =
quote generated: true do
parent = unquote(parent)
opts = unquote(opts)
parent_opts = unquote(parent_opts)
their_opt_schema = unquote(their_opt_schema)
@opts opts
@before_compile Spark.Dsl
@after_compile __MODULE__
@spark_is parent
@spark_parent parent
def spark_is, do: @spark_is
defmacro __after_compile__(_, _) do
quote do
transformers_to_run =
@extensions
|> Enum.flat_map(& &1.transformers())
|> Spark.Dsl.Transformer.sort()
|> Enum.filter(& &1.after_compile?())
__MODULE__
|> Spark.Dsl.Extension.run_transformers(
transformers_to_run,
@spark_dsl_config,
__ENV__
)
end
end
Module.register_attribute(__MODULE__, :persist, accumulate: true)
opts
|> @spark_parent.handle_opts()
|> Code.eval_quoted([], __ENV__)
if opts[:otp_app] do
@persist {:otp_app, opts[:otp_app]}
end
@persist {:module, __MODULE__}
for single_extension_kind <- parent_opts[:single_extension_kinds] do
@persist {single_extension_kind, opts[single_extension_kind]}
Module.put_attribute(__MODULE__, single_extension_kind, opts[single_extension_kind])
end
for many_extension_kind <- parent_opts[:many_extension_kinds] do
@persist {many_extension_kind, opts[many_extension_kind] || []}
Module.put_attribute(
__MODULE__,
many_extension_kind,
opts[many_extension_kind] || []
)
end
end
preparations = Spark.Dsl.Extension.prepare(extensions)
[body | preparations]
end
end
end
@doc false
def unwrap({:ok, value}), do: value
def unwrap({:error, error}), do: raise(error)
@doc false
def expand_modules(opts, their_opt_schema, env) do
Enum.reduce(opts, {[], []}, fn {key, value}, {opts, extensions} ->
cond do
key in their_opt_schema[:single_extension_kinds] ->
mod = Macro.expand(value, env)
extensions =
if Spark.implements_behaviour?(mod, Spark.Dsl.Extension) do
[mod | extensions]
else
extensions
end
{Keyword.put(opts, key, mod), extensions}
key in their_opt_schema[:many_extension_kinds] || key == :extensions ->
mods =
value
|> List.wrap()
|> Enum.map(&Macro.expand(&1, env))
extensions =
extensions ++
Enum.filter(mods, &Spark.implements_behaviour?(&1, Spark.Dsl.Extension))
{Keyword.put(opts, key, mods), extensions}
true ->
{Keyword.put(opts, key, value), extensions}
end
end)
end
defmacro __before_compile__(env) do
parent = Module.get_attribute(env.module, :spark_parent)
opts = Module.get_attribute(env.module, :opts)
parent_code = parent.handle_before_compile(opts)
code =
quote generated: true, bind_quoted: [dsl: __MODULE__] do
require Spark.Dsl.Extension
Module.register_attribute(__MODULE__, :spark_is, persist: true)
Module.put_attribute(__MODULE__, :spark_is, @spark_is)
Spark.Dsl.Extension.set_state(@persist)
for {block, bindings} <- @spark_dsl_config[:eval] || [] do
Code.eval_quoted(block, bindings, __ENV__)
end
def __spark_placeholder__, do: nil
def spark_dsl_config do
@spark_dsl_config
end
if @moduledoc do
@moduledoc """
#{@moduledoc}
#{Spark.Dsl.Extension.explain(@extensions, @spark_dsl_config)}
"""
else
@moduledoc Spark.Dsl.Extension.explain(@extensions, @spark_dsl_config)
end
end
[code, parent_code]
end
def is?(module, type) when is_atom(module) do
module.spark_is() == type
rescue
_ -> false
end
def is?(_module, _type), do: false
end
