Dataloader example

lib/blog/application.ex

@@ -14,6 +14,8 @@ defmodule Blog.Application do
       supervisor(BlogWeb.Endpoint, []),
       # Start your own worker by calling: Blog.Worker.start_link(arg1, arg2, arg3)
       # worker(Blog.Worker, [arg1, arg2, arg3]),
+      # Start Subscription supervisor processes
+      supervisor(Absinthe.Subscription, [BlogWeb.Endpoint])
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html

lib/blog/content/content.ex

@@ -3,6 +3,13 @@ defmodule Blog.Content do
 
   alias Blog.{Repo, Content}
 
+
+  def data(), do: Dataloader.Ecto.new(Repo, query: &query/2)
+
+  def query(queryable, params) do  
+    queryable
+  end 
+
   def list_posts(author, %{date: date}) do
     from(t in Content.Post,
       where: t.author_id == ^author.id,

lib/blog_web/channels/user_socket.ex

@@ -1,5 +1,6 @@
 defmodule BlogWeb.UserSocket do
   use Phoenix.Socket
+  use Absinthe.Phoenix.Socket, schema: BlogWeb.Schema
 
   ## Channels
   # channel "room:*", BlogWeb.RoomChannel

lib/blog_web/endpoint.ex

@@ -1,5 +1,6 @@
 defmodule BlogWeb.Endpoint do
   use Phoenix.Endpoint, otp_app: :blog
+  use Absinthe.Phoenix.Endpoint
 
   socket "/socket", BlogWeb.UserSocket
 

lib/blog_web/resolvers/content.ex

@@ -8,10 +8,19 @@ defmodule BlogWeb.Resolvers.Content do
   end
 
   def create_post(_parent, args, %{context: %{current_user: user}}) do
-    Blog.Content.create_post(user, args)
+    # Blog.Content.create_post(user, args)
+    case Blog.Content.create_post(user, args) do
+      {:ok, post} ->
+        Absinthe.Subscription.publish(BlogWeb.Endpoint, post,
+        new_post: "*"
+        )
+
+        {:ok, post}
+      {:error, changeset} ->
+        {:ok, "error"}
+      end
   end
   def create_post(_parent, _args, _resolution) do
     {:error, "Access denied"}
   end
-
 end

lib/blog_web/router.ex

@@ -10,10 +10,12 @@ defmodule BlogWeb.Router do
     pipe_through :api
 
     forward "/graphiql", Absinthe.Plug.GraphiQL,
-      schema: BlogWeb.Schema
+      schema: BlogWeb.Schema,
+      socket: BlogWeb.UserSocket
 
     forward "/", Absinthe.Plug,
-      schema: BlogWeb.Schema
+      schema: BlogWeb.Schema,
+      socket: BlogWeb.UserSocket
   end
 
 end

lib/blog_web/schema.ex

@@ -6,7 +6,23 @@ defmodule BlogWeb.Schema do
   import_types BlogWeb.Schema.ContentTypes
 
   alias BlogWeb.Resolvers
+  alias Blog.Content
 
+
+  # =============
+  # Dataloader 
+  def context(ctx) do
+     loader =
+       Dataloader.new()
+       |> Dataloader.add_source(Content, Content.data())
+
+    Map.put(ctx, :loader, loader)
+  end
+
+  def plugins do
+    [Absinthe.Middleware.Dataloader | Absinthe.Plugin.defaults()]
+  end
+
   query do
 
     @desc "Get all posts"
@@ -44,4 +60,12 @@ defmodule BlogWeb.Schema do
 
   end
 
+  subscription do
+    field :new_post, :post do
+      config fn _args, _info ->
+        {:ok, topic: "*"}
+      end
+    end 
+  end
+
 end

lib/blog_web/schema/account_types.ex

@@ -2,6 +2,8 @@ defmodule BlogWeb.Schema.AccountTypes do
   use Absinthe.Schema.Notation
 
   alias BlogWeb.Resolvers
+  alias Blog.Content
+  import Absinthe.Resolution.Helpers, only: [dataloader: 1]
 
   @desc "A user of the blog"
   object :user do
@@ -10,7 +12,7 @@ defmodule BlogWeb.Schema.AccountTypes do
     field :contacts, list_of(:contact)
     field :posts, list_of(:post) do
       arg :date, :date
-      resolve &Resolvers.Content.list_posts/3
+      resolve dataloader(Content)
     end
   end
 

mix.exs

@@ -33,16 +33,18 @@ defmodule Blog.Mixfile do
   # Type `mix help deps` for examples and options.
   defp deps do
     [
+      {:dataloader, "~> 1.0.4"},
       {:phoenix, "~> 1.3.0"},
       {:phoenix_pubsub, "~> 1.0"},
       {:phoenix_ecto, "~> 3.2"},
       {:ecto, "~> 2.2.6"},
       {:postgrex, ">= 0.0.0"},
       {:gettext, "~> 0.11"},
       {:cowboy, "~> 1.0"},
-      {:absinthe, "~> 1.4"},
+      {:absinthe, "~> 1.4.13"},
       {:absinthe_plug, "~> 1.4"},
       {:absinthe_ecto, ">= 0.0.0"},
+      {:absinthe_phoenix, "~> 1.4.0"},
       {:comeonin, "~> 4.0"},
       {:argon2_elixir, "~> 1.2"},
     ]

mix.lock

@@ -1,23 +1,27 @@
-%{"absinthe": {:hex, :absinthe, "1.4.0", "f2261f4bf62dd03a5fc75472b6ebfaa262f7133386d759cb965067e633888b0c", [], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
-  "absinthe_ecto": {:hex, :absinthe_ecto, "0.1.3", "420b68129e79fe4571a4838904ba03e282330d335da47729ad52ffd7b8c5fcb1", [], [{:absinthe, "~> 1.3.0 or ~> 1.4.0", [hex: :absinthe, repo: "hexpm", optional: false]}, {:ecto, ">= 0.0.0", [hex: :ecto, repo: "hexpm", optional: false]}], "hexpm"},
-  "absinthe_plug": {:hex, :absinthe_plug, "1.4.0", "321ba4da280d4dcea5d6cce0f4a0b28aba2b32bee25f2f0855a8dc5ca02d29cf", [], [{:absinthe, "~> 1.4", [hex: :absinthe, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.2 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
-  "argon2_elixir": {:hex, :argon2_elixir, "1.2.9", "359502d89aa82c8a0b0b690e752a3120790528b5993299abbbcf0165fa1771bf", [], [{:elixir_make, "~> 0.4", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm"},
-  "comeonin": {:hex, :comeonin, "4.0.3", "4e257dcb748ed1ca2651b7ba24fdbd1bd24efd12482accf8079141e3fda23a10", [], [{:argon2_elixir, "~> 1.2", [hex: :argon2_elixir, repo: "hexpm", optional: true]}, {:bcrypt_elixir, "~> 0.12.1 or ~> 1.0", [hex: :bcrypt_elixir, repo: "hexpm", optional: true]}, {:pbkdf2_elixir, "~> 0.12", [hex: :pbkdf2_elixir, repo: "hexpm", optional: true]}], "hexpm"},
-  "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [], [], "hexpm"},
-  "cowboy": {:hex, :cowboy, "1.1.2", "61ac29ea970389a88eca5a65601460162d370a70018afe6f949a29dca91f3bb0", [], [{:cowlib, "~> 1.0.2", [hex: :cowlib, repo: "hexpm", optional: false]}, {:ranch, "~> 1.3.2", [hex: :ranch, repo: "hexpm", optional: false]}], "hexpm"},
-  "cowlib": {:hex, :cowlib, "1.0.2", "9d769a1d062c9c3ac753096f868ca121e2730b9a377de23dec0f7e08b1df84ee", [], [], "hexpm"},
-  "db_connection": {:hex, :db_connection, "1.1.2", "2865c2a4bae0714e2213a0ce60a1b12d76a6efba0c51fbda59c9ab8d1accc7a8", [], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
-  "decimal": {:hex, :decimal, "1.4.1", "ad9e501edf7322f122f7fc151cce7c2a0c9ada96f2b0155b8a09a795c2029770", [], [], "hexpm"},
-  "ecto": {:hex, :ecto, "2.2.6", "3fd1067661d6d64851a0d4db9acd9e884c00d2d1aa41cc09da687226cf894661", [], [{:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: true]}, {:decimal, "~> 1.2", [hex: :decimal, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.8.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.13.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
+%{
+  "absinthe": {:hex, :absinthe, "1.4.13", "81eb2ff41f1b62cd6e992955f62c22c042d1079b7936c27f5f7c2c806b8fc436", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
+  "absinthe_ecto": {:hex, :absinthe_ecto, "0.1.3", "420b68129e79fe4571a4838904ba03e282330d335da47729ad52ffd7b8c5fcb1", [:mix], [{:absinthe, "~> 1.3.0 or ~> 1.4.0", [hex: :absinthe, repo: "hexpm", optional: false]}, {:ecto, ">= 0.0.0", [hex: :ecto, repo: "hexpm", optional: false]}], "hexpm"},
+  "absinthe_phoenix": {:hex, :absinthe_phoenix, "1.4.2", "cb84c81b94103fdfbbdd8b83b7b4b70a850ab7d3be6a1e56b96de2bb854b09b6", [:mix], [{:absinthe, "~> 1.4.0", [hex: :absinthe, repo: "hexpm", optional: false]}, {:absinthe_plug, "~> 1.4.0", [hex: :absinthe_plug, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.2", [hex: :phoenix, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.10.5", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:poison, "~> 2.0 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
+  "absinthe_plug": {:hex, :absinthe_plug, "1.4.0", "321ba4da280d4dcea5d6cce0f4a0b28aba2b32bee25f2f0855a8dc5ca02d29cf", [:mix], [{:absinthe, "~> 1.4", [hex: :absinthe, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.2 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
+  "argon2_elixir": {:hex, :argon2_elixir, "1.2.9", "359502d89aa82c8a0b0b690e752a3120790528b5993299abbbcf0165fa1771bf", [:make, :mix], [{:elixir_make, "~> 0.4", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm"},
+  "comeonin": {:hex, :comeonin, "4.0.3", "4e257dcb748ed1ca2651b7ba24fdbd1bd24efd12482accf8079141e3fda23a10", [:mix], [{:argon2_elixir, "~> 1.2", [hex: :argon2_elixir, repo: "hexpm", optional: true]}, {:bcrypt_elixir, "~> 0.12.1 or ~> 1.0", [hex: :bcrypt_elixir, repo: "hexpm", optional: true]}, {:pbkdf2_elixir, "~> 0.12", [hex: :pbkdf2_elixir, repo: "hexpm", optional: true]}], "hexpm"},
+  "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [:mix], [], "hexpm"},
+  "cowboy": {:hex, :cowboy, "1.1.2", "61ac29ea970389a88eca5a65601460162d370a70018afe6f949a29dca91f3bb0", [:rebar3], [{:cowlib, "~> 1.0.2", [hex: :cowlib, repo: "hexpm", optional: false]}, {:ranch, "~> 1.3.2", [hex: :ranch, repo: "hexpm", optional: false]}], "hexpm"},
+  "cowlib": {:hex, :cowlib, "1.0.2", "9d769a1d062c9c3ac753096f868ca121e2730b9a377de23dec0f7e08b1df84ee", [:make], [], "hexpm"},
+  "dataloader": {:hex, :dataloader, "1.0.4", "7c2345c53c9e5b61420013fc53c8463ba347a938b61f66677eb47d9c4a53ac5d", [:mix], [{:ecto, ">= 0.0.0", [hex: :ecto, repo: "hexpm", optional: true]}], "hexpm"},
+  "db_connection": {:hex, :db_connection, "1.1.2", "2865c2a4bae0714e2213a0ce60a1b12d76a6efba0c51fbda59c9ab8d1accc7a8", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
+  "decimal": {:hex, :decimal, "1.5.0", "b0433a36d0e2430e3d50291b1c65f53c37d56f83665b43d79963684865beab68", [:mix], [], "hexpm"},
+  "ecto": {:hex, :ecto, "2.2.6", "3fd1067661d6d64851a0d4db9acd9e884c00d2d1aa41cc09da687226cf894661", [:mix], [{:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: true]}, {:decimal, "~> 1.2", [hex: :decimal, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.8.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.13.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
   "ecto_enum": {:hex, :ecto_enum, "0.3.1", "28771a73c195553b32b434f926302092ba072ba2b50224b8d63081cad5e0846b", [], [{:ecto, ">= 0.13.1", [hex: :ecto, repo: "hexpm", optional: false]}, {:mariaex, ">= 0.3.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:postgrex, ">= 0.8.3", [hex: :postgrex, repo: "hexpm", optional: true]}], "hexpm"},
-  "elixir_make": {:hex, :elixir_make, "0.4.0", "992f38fabe705bb45821a728f20914c554b276838433349d4f2341f7a687cddf", [], [], "hexpm"},
-  "gettext": {:hex, :gettext, "0.13.1", "5e0daf4e7636d771c4c71ad5f3f53ba09a9ae5c250e1ab9c42ba9edccc476263", [], [], "hexpm"},
-  "mime": {:hex, :mime, "1.1.0", "01c1d6f4083d8aa5c7b8c246ade95139620ef8effb009edde934e0ec3b28090a", [], [], "hexpm"},
-  "phoenix": {:hex, :phoenix, "1.3.0", "1c01124caa1b4a7af46f2050ff11b267baa3edb441b45dbf243e979cd4c5891b", [], [{:cowboy, "~> 1.0", [hex: :cowboy, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.3 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
-  "phoenix_ecto": {:hex, :phoenix_ecto, "3.3.0", "702f6e164512853d29f9d20763493f2b3bcfcb44f118af2bc37bb95d0801b480", [], [{:ecto, "~> 2.1", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.9", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
-  "phoenix_pubsub": {:hex, :phoenix_pubsub, "1.0.2", "bfa7fd52788b5eaa09cb51ff9fcad1d9edfeb68251add458523f839392f034c1", [], [], "hexpm"},
-  "plug": {:hex, :plug, "1.4.3", "236d77ce7bf3e3a2668dc0d32a9b6f1f9b1f05361019946aae49874904be4aed", [], [{:cowboy, "~> 1.0.1 or ~> 1.1", [hex: :cowboy, repo: "hexpm", optional: true]}, {:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm"},
-  "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [], [], "hexpm"},
-  "poolboy": {:hex, :poolboy, "1.5.1", "6b46163901cfd0a1b43d692657ed9d7e599853b3b21b95ae5ae0a777cf9b6ca8", [], [], "hexpm"},
-  "postgrex": {:hex, :postgrex, "0.13.3", "c277cfb2a9c5034d445a722494c13359e361d344ef6f25d604c2353185682bfc", [], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm"},
-  "ranch": {:hex, :ranch, "1.3.2", "e4965a144dc9fbe70e5c077c65e73c57165416a901bd02ea899cfd95aa890986", [], [], "hexpm"}}
+  "elixir_make": {:hex, :elixir_make, "0.4.0", "992f38fabe705bb45821a728f20914c554b276838433349d4f2341f7a687cddf", [:mix], [], "hexpm"},
+  "gettext": {:hex, :gettext, "0.13.1", "5e0daf4e7636d771c4c71ad5f3f53ba09a9ae5c250e1ab9c42ba9edccc476263", [:mix], [], "hexpm"},
+  "mime": {:hex, :mime, "1.1.0", "01c1d6f4083d8aa5c7b8c246ade95139620ef8effb009edde934e0ec3b28090a", [:mix], [], "hexpm"},
+  "phoenix": {:hex, :phoenix, "1.3.0", "1c01124caa1b4a7af46f2050ff11b267baa3edb441b45dbf243e979cd4c5891b", [:mix], [{:cowboy, "~> 1.0", [hex: :cowboy, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.3 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
+  "phoenix_ecto": {:hex, :phoenix_ecto, "3.3.0", "702f6e164512853d29f9d20763493f2b3bcfcb44f118af2bc37bb95d0801b480", [:mix], [{:ecto, "~> 2.1", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.9", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
+  "phoenix_pubsub": {:hex, :phoenix_pubsub, "1.0.2", "bfa7fd52788b5eaa09cb51ff9fcad1d9edfeb68251add458523f839392f034c1", [:mix], [], "hexpm"},
+  "plug": {:hex, :plug, "1.4.3", "236d77ce7bf3e3a2668dc0d32a9b6f1f9b1f05361019946aae49874904be4aed", [:mix], [{:cowboy, "~> 1.0.1 or ~> 1.1", [hex: :cowboy, repo: "hexpm", optional: true]}, {:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm"},
+  "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm"},
+  "poolboy": {:hex, :poolboy, "1.5.1", "6b46163901cfd0a1b43d692657ed9d7e599853b3b21b95ae5ae0a777cf9b6ca8", [:rebar], [], "hexpm"},
+  "postgrex": {:hex, :postgrex, "0.13.3", "c277cfb2a9c5034d445a722494c13359e361d344ef6f25d604c2353185682bfc", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm"},
+  "ranch": {:hex, :ranch, "1.3.2", "e4965a144dc9fbe70e5c077c65e73c57165416a901bd02ea899cfd95aa890986", [:rebar3], [], "hexpm"},
+}