Build your own web framework in Elixir

Do you use Phoenix, but you don’t know how it works underneath the hood? Do you have a nagging feeling that you should know more about the ins and outs of processing a web request and turning it into a rendered page?

Good, then this talk is for you!

Understanding how a web framework turns a request into a rendered page is an important aspect of building web applications. And what better way to learn the fundamentals of how a web framework works than to build one in Elixir? So join me as we build a web framework in Elixir complete with a router, controllers, and templates. We’ll take a look at how Plug has already done most of the work for us and at how we can leverage such a powerful abstraction to extend what it gives us. We’ll even look at how to make our templates render blazingly fast by compiling them into functions.

You may not be ready to bet your business on this new framework, but by the end of the talk, you’ll certainly be better equipped to understand what Phoenix is doing underneath macros and to extend it with new functionality. And hey, if you really want to create a new framework, you’ll get a solid start.

Transcript

1. Build your own web framework German Velasco @germsvel
2. thoughtbot
3. github.com/ germsvel/daze
4. Cowboy Plug EEx
5. Plug's specification defmodule Daze.Plug do def init(opts), do: opts def call(conn, _opts) do conn end end
6. Plug's specification defmodule Daze.Plug do def init(opts), do: opts def call(conn, _opts) do conn end end
7. Plug's specification defmodule Daze.Plug do def init(opts), do: opts def call(conn, _opts) do conn end end
8. Plug's specification defmodule Daze.Plug do def init(opts), do: opts def call(conn, _opts) do conn end end
9. The Basics
10. mix new daze --sup
11. config/ deps/ lib/ test/ mix.exs mix.lock
12. defmodule Daze.Mixfile do def application do [ extra_applications: [:logger, :cowboy, :plug], mod: {Daze.Application, []} ] end defp deps do [ {:cowboy, "~> 1.1.0"}, {:plug, "~> 1.4.0"} ] end end
13. defmodule Daze.Mixfile do def application do [ extra_applications: [:logger, :cowboy, :plug], mod: {Daze.Application, []} ] end defp deps do [ {:cowboy, "~> 1.1.0"}, {:plug, "~> 1.4.0"} ] end end
14. defmodule Daze.Mixfile do def application do [ extra_applications: [:logger, :cowboy, :plug], mod: {Daze.Application, []} ] end defp deps do [ {:cowboy, "~> 1.1.0"}, {:plug, "~> 1.4.0"} ] end end
15. mix deps.get
16. config/ deps/ lib/ daze/ application.ex test/ mix.exs mix.lock
17. defmodule Daze.Application do use Application def start(_type, _args) do children = [ ] opts = [strategy: :one_for_one, name: Daze.Supervisor] Supervisor.start_link(children, opts) end end
18. defmodule Daze.Application do use Application def start(_type, _args) do children = [ {Plug.Adapters.Cowboy, } ] opts = [strategy: :one_for_one, name: Daze.Supervisor] Supervisor.start_link(children, opts) end end
19. defmodule Daze.Application do use Application def start(_type, _args) do children = [ {Plug.Adapters.Cowboy, scheme: :http, } ] opts = [strategy: :one_for_one, name: Daze.Supervisor] Supervisor.start_link(children, opts) end end
20. defmodule Daze.Application do use Application def start(_type, _args) do children = [ {Plug.Adapters.Cowboy, scheme: :http, options: [port: 4001]} ] opts = [strategy: :one_for_one, name: Daze.Supervisor] Supervisor.start_link(children, opts) end end
21. defmodule Daze.Application do use Application def start(_type, _args) do children = [ {Plug.Adapters.Cowboy, scheme: :http, plug: Daze.Router, options: [port: 4001]} ] opts = [strategy: :one_for_one, name: Daze.Supervisor] Supervisor.start_link(children, opts) end end
22. config/ deps/ lib/ daze/ + router.ex test/ mix.exs mix.lock
23. defmodule Daze.Router do end
24. defmodule Daze.Router do use Plug.Router end
25. defmodule Daze.Router do use Plug.Router plug :match plug :dispatch end
26. defmodule Daze.Router do use Plug.Router plug :match plug :dispatch get "/" do send_resp(conn, 200, "We have a router!") end end
27. mix run --no-halt
29. Are we getting requests?
30. defmodule Daze.Router do use Plug.Router plug :match plug :dispatch get "/" do send_resp(conn, 200, "We have a router!") end end
31. defmodule Daze.Router do use Plug.Router plug Plug.Logger plug :match plug :dispatch get "/" do send_resp(conn, 200, "We have a router!") end end
33. mix daze.server config/ deps/ lib/ mix/ tasks/ + daze.server.ex test/ mix.exs mix.lock
34. defmodule Mix.Tasks.Daze.Server do use Mix.Task def run(args) do Mix.Tasks.Run.run(args ++ ["--no-halt"]) end end
35. defmodule Mix.Tasks.Daze.Server do use Mix.Task def run(args) do Mix.Tasks.Run.run(args ++ ["--no-halt"]) end end
36. defmodule Mix.Tasks.Daze.Server do use Mix.Task require Logger def run(args) do Logger.info("Starting Daze Server") Mix.Tasks.Run.run(args ++ ["--no-halt"]) end end
39. defmodule Daze.Router do use Plug.Router if Mix.env() == :dev do use Plug.Debugger end plug Plug.Logger plug :match plug :dispatch get "/" do send_resp(conn, 200, "We have a router!") end end
40. defmodule Daze.Router do use Plug.Router if Mix.env() == :dev do use Plug.Debugger, style: [primary: "#c0392b", accent: "#41B577"] end plug Plug.Logger plug :match plug :dispatch get "/" do send_resp(conn, 200, "We have a router!") end end
42. Controllers, Views, and Templates
43. Extract controller logic
44. defmodule Daze.Router do use Plug.Router # snip get "/" do send_resp(conn, 200, "We have a router!") end end
45. defmodule Daze.Router do use Plug.Router # snip get "/", to: Daze.Actions.Posts.Index end
46. config/ deps/ lib/ daze/ actions/ posts/ + index.ex test/ mix.exs mix.lock
47. Plugs, remember? defmodule Daze.Actions.Posts.Index do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
48. Plugs, remember? defmodule Daze.Actions.Posts.Index do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
49. Plugs, remember? defmodule Daze.Actions.Posts.Index do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
50. Plugs, remember? defmodule Daze.Actions.Posts.Index do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
52. Templates with EEx
53. defmodule Daze.Actions.Posts.Index do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
54. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
55. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
56. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex" def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
57. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:adjective] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, "Plugs all the way down!") end end
58. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:adjective] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, index("coolest")) end end
59. config/ deps/ lib/ daze/ templates/ posts/ + index.html.ex test/ mix.exs mix.lock
60. <!DOCTYPE html> <html> <head> </head> <body> EEx is the <%= adjective %>! </body> </html>
61. <!DOCTYPE html> <html> <head> </head> <body> EEx is the <%= adjective %>! </body> </html>
63. <!DOCTYPE html> <html> <head> </head> <body> EEx is the <%= adjective1 %> and the <%= adjective2 %>! </body> </html>
64. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:adjective1, :adjective2] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, index("coolest", "fastest")) end end
65. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, index(adjective1: "coolest", adjective2: "fastest")) end end
66. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, index(adjective1: "coolest", adjective2: "fastest")) end end
67. <!DOCTYPE html> <html> <head> </head> <body> EEx is the <%= @adjective1 %> and the <%= @adjective2 %>! </body> </html>
69. Views
70. defmodule Daze.Actions.Posts.Index do import Plug.Conn require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, index(adjective1: "coolest", adjective2: "fastest")) end end
71. defmodule Daze.Actions.Posts.Index do import Plug.Conn - require EEx - EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] def init(opts), do: opts def call(conn, _opts) do send_resp(conn, 200, index(adjective1: "coolest", adjective2: "fastest")) end end
72. config/ deps/ lib/ daze/ views/ + posts.ex test/ mix.exs mix.lock
73. defmodule Daze.Views.Posts do end
74. defmodule Daze.Views.Posts do require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] end
75. defmodule Daze.Actions.Posts.Index do import Plug.Conn alias Daze.Views.Posts def init(opts), do: opts def call(conn, _opts) do conn |> send_resp(200, Posts.index(adjective1: "coolest", adjective2: "fastest")) end end
76. defmodule Daze.Actions.Posts.Index do import Plug.Conn alias Daze.Views.Posts def init(opts), do: opts def call(conn, _opts) do conn |> send_resp(200, Posts.index(adjective1: "coolest", adjective2: "fastest")) end end
78. Handling forms
79. <!DOCTYPE html> <html> <head> </head> <body> <h1>Posts</h1> <div> <form action="/posts" method="post"> <label>Post:</label> <textarea name="post"></textarea> <label>Author</label> <input type="text" name="author"> <button type="submit">Post</button> </form> </div> </body> </html>
80. <!DOCTYPE html> <html> <head> </head> <body> <h1>Posts</h1> <div> <form action="/posts" method="post"> <label>Post:</label> <textarea name="post"></textarea> <label>Author</label> <input type="text" name="author"> <button type="submit">Post</button> </form> </div> </body> </html>
81. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug :dispatch get "/", to: Daze.Actions.Posts.Index end
82. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :dispatch get "/", to: Daze.Actions.Posts.Index end
83. conn # => %Plug.Conn{ query_params: _, body_params: _, params: _ }
84. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :dispatch get "/", to: Daze.Actions.Posts.Index end
85. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :dispatch get "/", to: Daze.Actions.Posts.Index post "/posts", to: Daze.Actions.Posts.Create end
86. config/ deps/ lib/ daze/ actions/ posts/ + create.ex test/ mix.exs mix.lock
87. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do end end
88. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params end
89. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params url = "/" end end
90. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params url = "/" conn end end
91. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params url = "/" conn |> put_resp_header("location", url) end end
92. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params url = "/" conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") end end
93. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params url = "/" conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end end
94. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params Daze.Repo.insert(author, %{body: post, author: author}) url = "/" conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end
95. config/ deps/ lib/ daze/ + repo.ex test/ mix.exs mix.lock
96. defmodule Daze.Repo do use Agent end
97. defmodule Daze.Repo do use Agent def start_link(_) do Agent.start_link(fn -> Map.new end, name: __MODULE__) end end
98. defmodule Daze.Repo do use Agent # snip def insert(key, value) do Agent.update(__MODULE__, fn map -> data = case Map.get(map, key) do nil -> [] values -> values end Map.put(map, key, [value | data]) end) end end
99. defmodule Daze.Repo do use Agent # snip def all do Agent.get(__MODULE__, fn map -> map |> Map.values() |> Enum.concat() end) end end
100. defmodule Daze.Application do @moduledoc false use Application def start(_type, _args) do children = [ {Plug.Adapters.Cowboy, scheme: :http, plug: Daze.Router, options: [port: 4001]}, {Daze.Repo, []} ] opts = [strategy: :one_for_one, name: Daze.Supervisor] Supervisor.start_link(children, opts) end end
101. defmodule Daze.Actions.Posts.Index do import Plug.Conn alias Daze.Views.Posts def init(opts), do: opts def call(conn, _opts) do posts = Daze.Repo.all() conn |> send_resp(200, Posts.index(posts: posts)) end end
102. <html> <body> # snip <%= if @posts do %> <ul> <%= for post <- @posts do %> <li> <%= post.body %> <strong>by <%= post.author %></strong> </li> <% end %> </ul> <% end %> </div> </body> </html>
103. <html> <body> # snip <%= if @posts do %> <ul> <%= for post <- @posts do %> <li> <%= post.body %> <strong>by <%= post.author %></strong> </li> <% end %> </ul> <% end %> </div> </body> </html>
104. <html> <body> # snip <%= if @posts do %> <ul> <%= for post <- @posts do %> <li> <%= post.body %> <strong>by <%= post.author %></strong> </li> <% end %> </ul> <% end %> </div> </body> </html>
107. Daze.Action
108. defmodule Daze.Actions.Posts.Index do import Plug.Conn alias Daze.Views.Posts def init(opts), do: opts def call(conn, _opts) do # snip end end
109. defmodule Daze.Actions.Posts.Create do import Plug.Conn def init(opts), do: opts def call(conn, _opts) do # snip end end
110. config/ deps/ lib/ daze/ + action.ex test/ mix.exs mix.lock
111. defmodule Daze.Action do defmacro __using__(opts) do quote do end end end
112. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn def init(opts), do: opts end end end
113. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() conn |> put_resp_content_type("text/html") |> send_resp(200, Posts.index(posts: posts)) end end
114. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() conn |> put_resp_content_type("text/html") |> send_resp(200, Posts.index(posts: posts)) end end
115. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() render(conn, Posts.index(posts: posts)) end def render(conn, body) do conn |> put_resp_content_type("text/html") |> send_resp(200, body) end end
116. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn def init(opts), do: opts end end end
117. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn import Daze.Action.Helpers def init(opts), do: opts end end end
118. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn import Daze.Action.Helpers def init(opts), do: opts end end defmodule Helpers do end end
119. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn import Daze.Action.Helpers def init(opts), do: opts end end defmodule Helpers do import Plug.Conn def render(conn, body) do conn |> put_resp_content_type("text/html") |> send_resp(200, body) end end end
120. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() render(conn, Posts.index(posts: posts)) end end
121. defmodule Daze.Actions.Posts.Create do use Daze.Action def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params Daze.Repo.insert(author, %{body: post, author: author}) url = "/" conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end end
122. defmodule Daze.Actions.Posts.Create do use Daze.Action def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params Daze.Repo.insert(author, %{body: post, author: author}) url = "/" conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end end
123. defmodule Daze.Actions.Posts.Create do use Daze.Action def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params Daze.Repo.insert(author, %{body: post, author: author}) redirect(conn, to: "/") end def redirect(conn, to: url) do conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end end
124. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn import Daze.Action.Helpers def init(opts), do: opts end end defmodule Helpers do import Plug.Conn def render(conn, body) do conn |> put_resp_content_type("text/html") |> send_resp(200, body) end end end
125. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn import Daze.Action.Helpers def init(opts), do: opts end end defmodule Helpers do import Plug.Conn def render(conn, body) do # snip end def redirect(conn, to: url) do conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end end end
126. defmodule Daze.Action do defmacro __using__(opts) do quote do import Plug.Conn import Daze.Action.Helpers def init(opts), do: opts end end defmodule Helpers do import Plug.Conn def render(conn, body) do # snip end def redirect(conn, to: url) do conn |> put_resp_header("location", url) |> put_resp_content_type("text/html") |> send_resp(302, "You are being redirected to #{url}") end end end
127. defmodule Daze.Actions.Posts.Create do use Daze.Action def call(conn, _opts) do %{ "post" => post, "author" => author } = conn.params Daze.Repo.insert(author, %{body: post, author: author}) redirect(conn, to: "/") end end
128. Daze.View
129. defmodule Daze.Views.Posts do require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] end
130. defmodule Daze.Views.Posts do require EEx EEx.function_from_file :def, :index, "lib/daze/templates/posts/index.html.eex", [:assigns] end
131. config/ deps/ lib/ daze/ + view.ex test/ mix.exs mix.lock
132. defmodule Daze.View do @root_path "lib/daze/templates" end
133. defmodule Daze.View do @root_path "lib/daze/templates" defmacro deftemplate(template_name, function_name) do end end
134. defmodule Daze.View do @root_path "lib/daze/templates" defmacro deftemplate(template_name, function_name) do template_path = Path.join(@root_path, template_name) end end
135. defmodule Daze.View do @root_path "lib/daze/templates" defmacro deftemplate(template_name, function_name) do template_path = Path.join(@root_path, template_name) quote do require EEx EEx.function_from_file( :def ) end end end
136. defmodule Daze.View do @root_path "lib/daze/templates" defmacro deftemplate(template_name, function_name) do template_path = Path.join(@root_path, template_name) quote do require EEx EEx.function_from_file( :def, unquote(function_name), unquote(template_path) ) end end end
137. defmodule Daze.View do @root_path "lib/daze/templates" defmacro deftemplate(template_name, function_name) do template_path = Path.join(@root_path, template_name) quote do require EEx EEx.function_from_file( :def, unquote(function_name), unquote(template_path), [:assigns] ) end end end
138. defmodule Daze.View do defmacro __using__(_) do quote do import Daze.View end end @root_path "lib/daze/templates" defmacro deftemplate(template_name, function_name) do template_path = Path.join(@root_path, template_name) quote do require EEx EEx.function_from_file( :def, unquote(function_name), unquote(template_path), [:assigns] ) end end end
139. defmodule Daze.Views.Posts do use Daze.View deftemplate("posts/index.html.eex", :index) end
141. Sessions
142. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :dispatch # snip end
143. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug Plug.Session, plug :dispatch # snip end
144. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug Plug.Session, store: :cookie, plug :dispatch # snip end
145. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug Plug.Session, store: :cookie, key: "_daze_app", plug :dispatch # snip end
146. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug Plug.Session, store: :cookie, key: "_daze_app", signing_salt: "daze salt" plug :dispatch # snip end
147. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "_daze_app", signing_salt: "daze salt" plug :dispatch # snip def put_secret_key_base(conn, _) do end end
148. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "_daze_app", signing_salt: "daze salt" plug :dispatch # snip def put_secret_key_base(conn, _) do put_in( conn.secret_key_base, "tosp2eJ0EVDXq/litnqe3iTMf4oGJuos0PbJk1NzkL4SaMEPB8OGu4T8Ym+WavGY" ) end end
149. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "_daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch # snip end
150. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "_daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch get "/", to: Daze.Actions.Posts.Index post "/posts", to: Daze.Actions.Posts.Create get "/sign_in", to: Daze.Actions.Sessions.New # snip end
151. config/ deps/ lib/ daze/ actions/ sessions/ + new.ex test/ mix.exs mix.lock
152. defmodule Daze.Actions.Sessions.New do use Daze.Action end
153. defmodule Daze.Actions.Sessions.New do use Daze.Action def call(conn, _opts) do render(conn, Daze.Views.Sessions.new([])) end end
154. config/ deps/ lib/ daze/ views/ + sessions.ex test/ mix.exs mix.lock
155. defmodule Daze.Views.Sessions do use Daze.View deftemplate("sessions/new.html.eex", :new) end
156. config/ deps/ lib/ daze/ templates/ sessions/ + new.html.eex test/ mix.exs mix.lock
157. <!DOCTYPE html> <html> <head> </head> <body> <h1>Sign in</h1> <div> <form action="/sessions" method="post"> <label>Email:</label> <input type="email" name="email"> <label>Password:</label> <input type="password" name="password"> <button type="submit">Sign in</button> </form> </div> </body> </html>
158. <!DOCTYPE html> <html> <head> </head> <body> <h1>Sign in</h1> <div> <form action="/sessions" method="post"> <label>Email:</label> <input type="email" name="email"> <label>Password:</label> <input type="password" name="password"> <button type="submit">Sign in</button> </form> </div> </body> </html>
160. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch get "/", to: Daze.Actions.Posts.Index post "/posts", to: Daze.Actions.Posts.Create get "/sign_in", to: Daze.Actions.Sessions.New post "/sessions", to: Daze.Actions.Sessions.Create # snip end
161. config/ deps/ lib/ daze/ actions/ sessions/ + create.ex test/ mix.exs mix.lock
162. defmodule Daze.Actions.Sessions.Create do use Daze.Action end
163. defmodule Daze.Actions.Sessions.Create do use Daze.Action def call(conn, _opts) do %{"email" => email} = conn.params conn |> put_session(:current_user_email, email) |> redirect(to: "/") end end
164. defmodule Daze.Actions.Sessions.Create do use Daze.Action def call(conn, _opts) do %{"email" => email} = conn.params conn |> put_session(:current_user_email, email) |> redirect(to: "/") end end
165. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() conn |> render(Posts.index(posts: posts)) end end
166. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() current_user_email = get_session(conn, :current_user_email) conn |> render(Posts.index(posts: posts)) end end
167. defmodule Daze.Actions.Posts.Index do use Daze.Action alias Daze.Views.Posts def call(conn, _opts) do posts = Daze.Repo.all() current_user_email = get_session(conn, :current_user_email) conn |> render(Posts.index(posts: posts, current_user_email: current_user_email)) end end
168. <!DOCTYPE html> <html> <head> </head> <body> <h1>Posts</h1> <%= if @current_user_email do %> Welcome <%= @current_user_email %> <% else %> <a href="/sign_in">Sign In</a> <% end %> # snip </div> </body> </html>
172. Static assets
173. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch # snip end
174. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug Plug.Static, plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch # snip end
175. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug Plug.Static, from: :daze, at: "/", plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch # snip end
176. defmodule Daze.Router do use Plug.Router # snip plug Plug.Logger plug Plug.Static, from: :daze, at: "/", only: ["images", "css"] plug :match plug Plug.Parsers, parsers: [:urlencoded, :multipart] plug :put_secret_key_base plug Plug.Session, store: :cookie, key: "daze_app", signing_salt: "daze salt" plug :fetch_session plug :dispatch # snip end
177. <!DOCTYPE html> <html> <head> <link rel="stylesheet" href="css/app.css"> </head> # snip </html>
178. config/ deps/ lib/ priv/ static/ css/ + app.css test/ mix.exs mix.lock
179. body { background-color: #fff; font-family: 'Open Sans', sans-serif; } .container { display: flex; flex-direction: column; } .header { display: flex; flex-flow: row nowrap; justify-content: space-evenly; align-items: center; margin: 4em; } .banner-image { width: 100px; } .main { display: flex; flex-flow: column nowrap; margin: auto; } .posts { margin: 3em 0.5em; } .post-item { margin: 0 0.5em 3em 0.5em; list-style: none; } .post-body { font-size: 1.5em; } .post-author { margin-top: 0.3em; display: block; text-align: right; }
180. <!DOCTYPE html> <html> <head> <link rel="stylesheet" href="css/app.css"> </head> <body> <div class="container"> <div class="header"> <img class="banner-image" src="images/elixir-daze.svg"> <h1>Posts</h1> # snip </div> </body> </html>
181. config/ deps/ lib/ priv/ static/ images/ + elixir-daze.svg test/ mix.exs mix.lock
182. Demo
184. Final thoughts
185. github.com/germsvel/daze @germsvel