Absinthe Query Args

.formatter.exs

@@ -11,7 +11,9 @@ locals_without_parens = [
   derive_event: 1,
   derive_event: 2,
   import_commands: 1,
-  import_commands: 2
+  import_commands: 2,
+  query_args: 1,
+  query_args: 2
 ]
 
 [

example/.formatter.exs

@@ -1,5 +1,5 @@
 # Used by "mix format"
 [
-  import_deps: [:commanded, :cqrs_tools, :ecto, :phoenix],
+  import_deps: [:absinthe, :commanded, :cqrs_tools, :ecto, :phoenix],
   inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
 ]

example/lib/example_api/resolvers/user_resolver.ex

@@ -7,6 +7,10 @@ defmodule ExampleApi.Resolvers.UserResolver do
 
   import ExecutionResultHelper
 
+  def user(args, _res) do
+     {:ok, Users.get_user!(args)}
+  end
+
   def users(args, _res) do
     args
     |> Users.list_users_query!()

example/lib/example_api/types/user_types.ex

@@ -1,7 +1,11 @@
 defmodule ExampleApi.Types.UserTypes do
   @moduledoc false
+  use Cqrs.Absinthe
   use Absinthe.Schema.Notation
   use Absinthe.Relay.Schema.Notation, :modern
+
+  alias Example.Queries.{ListUsers, GetUser}
+
   import ExampleApi.Resolvers.UserResolver
 
   enum :user_status do
@@ -19,10 +23,13 @@ defmodule ExampleApi.Types.UserTypes do
   connection(node_type: :user)
 
   object :user_queries do
+    field :user, :user do
+      query_args GetUser, except: [:name]
+      resolve &user/2
+    end
+
     connection field :users, node_type: :user do
-      arg :status, :user_status
-      arg :email, :string
-      arg :name, :string
+      query_args ListUsers, status: :user_status
       resolve &users/2
     end
   end

lib/cqrs/absinthe.ex

@@ -0,0 +1,83 @@
+if Code.ensure_loaded?(Absinthe) do
+  defmodule Cqrs.Absinthe do
+    defmacro __using__(_) do
+      quote do
+        import Cqrs.Absinthe, only: [query_args: 1, query_args: 2]
+      end
+    end
+
+    @doc """
+    Creates args for an `Absinthe` query from a [query's](`Cqrs.Query`) filters.
+
+    ## Options
+
+    * `:only` - Restrict importing to only the filters listed
+    * `:except` - Imports all filters except for those listed
+    * any filter name to an existing absinthe_type
+
+    ## Examples
+        field :user, :user do
+          query_args GetUser, except: [:name]
+          resolve &user/2
+        end
+
+        connection field :users, node_type: :user do
+          query_args ListUsers, status: :user_status
+          resolve &users/2
+        end
+
+    """
+    defmacro query_args(query_module, opts \\ []) do
+      query_args = __create_query_args__(query_module, opts)
+      Module.eval_quoted(__CALLER__, query_args)
+    end
+
+    def __create_query_args__(query_module, opts) do
+      quote do
+        _ = unquote(query_module).__info__(:functions)
+
+        unless function_exported?(unquote(query_module), :__query__, 0) do
+          raise Cqrs.BoundedContext.InvalidQueryError, query: unquote(query_module)
+        end
+
+        filters = Cqrs.Absinthe.__extract_filters__(unquote(query_module), unquote(opts))
+        |> Enum.map(fn {name, absinthe_type, required} ->
+          case required do
+            true -> quote do: arg(unquote(name), non_null(unquote(absinthe_type)))
+            false -> quote do: arg(unquote(name), unquote(absinthe_type))
+          end
+        end)
+      end
+    end
+
+    def __extract_filters__(query_module, opts) do
+      filters = query_module.__filters__()
+
+      only = Keyword.get(opts, :only, [])
+      except = Keyword.get(opts, :except, [])
+
+      filters =
+        case {only, except} do
+          {[], []} -> filters
+          {[], except} -> Enum.reject(filters, &Enum.member?(except, elem(&1, 0)))
+          {only, []} -> Enum.filter(filters, &Enum.member?(only, elem(&1, 0)))
+          _ -> raise "You can only specify :only or :except"
+        end
+
+      Enum.map(filters, fn filter ->
+        {name, _type, filter_opts} = filter
+        absinthe_type = Cqrs.Absinthe.__absinthe_type__(filter, opts)
+        required = Keyword.get(filter_opts, :required, false)
+        {name, absinthe_type, required}
+      end)
+    end
+
+    def __absinthe_type__({name, Ecto.Enum, _}, opts) do
+      enum_type = Keyword.get(opts, name) || raise "Must supply absinthe enum type for #{name}"
+      quote do: unquote(enum_type)
+    end
+
+    def __absinthe_type__({_name, :binary_id, _}, _opts), do: quote(do: :id)
+    def __absinthe_type__({_name, type, _}, _opts), do: quote(do: unquote(type))
+  end
+end

lib/cqrs/bounded_context.ex

@@ -337,8 +337,9 @@ defmodule Cqrs.BoundedContext do
         commands =
           case {only, except} do
             {[], []} -> commands
-            {_only, except} -> Enum.reject(commands, &Enum.member?(except, &1))
-            {only, _except} -> Enum.filter(commands, &Enum.member?(only, &1))
+            {[], except} -> Enum.reject(commands, &Enum.member?(except, &1))
+            {only, []} -> Enum.filter(commands, &Enum.member?(only, &1))
+            _ -> raise "You can only specify :only or :except"
           end
 
         Enum.map(commands, fn module -> BoundedContext.command(module, unquote(opts)) end)

lib/cqrs/query.ex

@@ -125,6 +125,7 @@ defmodule Cqrs.Query do
 
       @filter_docs Documentation.field_docs("Filters", @filters, @required_filters)
 
+      def __filters__, do: @filters
       def __filter_docs__, do: @filter_docs
       def __module_docs__, do: @moduledoc
       def __query__, do: String.trim_leading(to_string(__MODULE__), "Elixir.")
@@ -196,7 +197,7 @@ defmodule Cqrs.Query do
       required = Keyword.get(unquote(opts), :required, @require_all_filters)
       if required, do: @required_filters(unquote(name))
 
-      @filters {unquote(name), unquote(type), unquote(opts)}
+      @filters {unquote(name), unquote(type), Keyword.put(unquote(opts), :required, required)}
     end
   end
 

mix.exs

@@ -1,7 +1,7 @@
 defmodule CqrsTools.MixProject do
   use Mix.Project
 
-  @version "0.1.6"
+  @version "0.1.7"
 
   def project do
     [
@@ -39,6 +39,7 @@ defmodule CqrsTools.MixProject do
     [
       {:ecto, "~> 3.2"},
       {:jason, "~> 1.2", optional: true},
+      {:absinthe, "~> 1.6", optional: true},
       {:ex_doc, "~> 0.24", only: :dev, runtime: false},
       {:commanded, "~> 1.2", only: [:dev, :test], runtime: false},
       {:elixir_uuid, "~> 1.6", override: true, hex: :uuid_utils, only: :test}

mix.lock

@@ -1,4 +1,5 @@
 %{
+  "absinthe": {:hex, :absinthe, "1.6.4", "d2958908b72ce146698de8ccbc03622630471eb0e354e06823aaef183e5067bd", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "6e9c1cf36d86c704cb9a9c78db62d1c2676b03e0f61a28a23fc42749e8cd41ae"},
   "backoff": {:hex, :backoff, "1.1.6", "83b72ed2108ba1ee8f7d1c22e0b4a00cfe3593a67dbc792799e8cce9f42f796b", [:rebar3], [], "hexpm", "cf0cfff8995fb20562f822e5cc47d8ccf664c5ecdc26a684cbe85c225f9d7c39"},
   "commanded": {:hex, :commanded, "1.2.0", "d0c604e885132cbca875c238b741e0e2059c54395b4087d3d91763ebf06254d2", [:mix], [{:backoff, "~> 1.1", [hex: :backoff, repo: "hexpm", optional: false]}, {:elixir_uuid, "~> 1.2", [hex: :elixir_uuid, repo: "hexpm", optional: false]}, {:jason, "~> 1.2", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: true]}], "hexpm", "64e51d04773d0b74568ea1d0886c57e350139438096992ad3456d9d80363d0b5"},
   "decimal": {:hex, :decimal, "2.0.0", "a78296e617b0f5dd4c6caf57c714431347912ffb1d0842e998e9792b5642d697", [:mix], [], "hexpm", "34666e9c55dea81013e77d9d87370fe6cb6291d1ef32f46a1600230b1d44f577"},