Elixir & Phoenix – fast, concurrent and explicit
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The document discusses Elixir and Phoenix, highlighting their features such as fast performance, concurrency, and explicitness. It includes code examples demonstrating key concepts like pattern matching, functional programming, and Ecto associations. The presentation concludes by questioning whether one should start new projects using Elixir and Phoenix, suggesting that the decision depends on individual circumstances.
![defmodule MyMap do
@doc """
iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
"""
def map(list, function) do
Enum.reverse do_map([], list, function)
end
defp do_map(acc, [], _function) do
acc
end
defp do_map(acc, [head | tail], function) do
do_map([function.(head) | acc], tail, function)
end
end](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-11-320.jpg)
![defmodule MyMap do
@doc """
iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
"""
def map(list, function) do
Enum.reverse do_map([], list, function)
end
defp do_map(acc, [], _function) do
acc
end
defp do_map(acc, [head | tail], function) do
do_map([function.(head) | acc], tail, function)
end
end
Ruby-like Syntax](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-12-320.jpg)
![defmodule MyMap do
@doc """
iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
"""
def map(list, function) do
Enum.reverse do_map([], list, function)
end
defp do_map(acc, [], _function) do
acc
end
defp do_map(acc, [head | tail], function) do
do_map([function.(head) | acc], tail, function)
end
end
First-class functions](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-14-320.jpg)
![defmodule MyMap do
@doc """
iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
"""
def map(list, function) do
Enum.reverse do_map([], list, function)
end
defp do_map(acc, [], _function) do
acc
end
defp do_map(acc, [head | tail], function) do
do_map([function.(head) | acc], tail, function)
end
end
Tail-Call Optimization](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-15-320.jpg)
![defmodule MyMap do
@doc """
iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
"""
def map(list, function) do
Enum.reverse do_map([], list, function)
end
defp do_map(acc, [], _function) do
acc
end
defp do_map(acc, [head | tail], function) do
do_map([function.(head) | acc], tail, function)
end
end
Pattern Matching](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-16-320.jpg)
![defmodule Patterns do
def greet(%{name: name, age: age}) do
IO.puts "Hi there #{name}, what's up at #{age}?"
end
def greet(%{name: "Denis Defreyne"}) do
IO.puts "Hi Denis, are you all set for your talk?"
end
def greet(%{name: name}) do
IO.puts "Hi there #{name}"
end
def greet(_) do
IO.puts "Hi"
end
end
Patterns.greet %{name: "Tobi", age: 27, something: :else}
Patterns.greet %{name: "Denis Defreyne"}
Patterns.greet %{name: "Tobi"}
Patterns.greet ["Mop"]
Pattern Matching](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-17-320.jpg)
![defmodule Patterns do
def greet(%{name: name, age: age}) do
IO.puts "Hi there #{name}, what's up at #{age}?"
end
def greet(%{name: "Denis Defreyne"}) do
IO.puts "Hi Denis, are you all set for your talk?"
end
def greet(%{name: name}) do
IO.puts "Hi there #{name}"
end
def greet(_) do
IO.puts "Hi"
end
end
Patterns.greet %{name: "Tobi", age: 27, something: :else}
Patterns.greet %{name: "Denis Defreyne"}
Patterns.greet %{name: "Tobi"}
Patterns.greet ["Mop"]
Pattern Matching](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-18-320.jpg)
![defmodule Patterns do
def greet(%{name: name, age: age}) do
IO.puts "Hi there #{name}, what's up at #{age}?"
end
def greet(%{name: "Denis Defreyne"}) do
IO.puts "Hi Denis, are you all set for your talk?"
end
def greet(%{name: name}) do
IO.puts "Hi there #{name}"
end
def greet(_) do
IO.puts "Hi"
end
end
Patterns.greet %{name: "Tobi", age: 27, something: :else}
Patterns.greet %{name: "Denis Defreyne"}
Patterns.greet %{name: "Tobi"}
Patterns.greet ["Mop"]
Pattern Matching](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-19-320.jpg)
![defmodule Patterns do
def greet(%{name: name, age: age}) do
IO.puts "Hi there #{name}, what's up at #{age}?"
end
def greet(%{name: "Denis Defreyne"}) do
IO.puts "Hi Denis, are you all set for your talk?"
end
def greet(%{name: name}) do
IO.puts "Hi there #{name}"
end
def greet(_) do
IO.puts "Hi"
end
end
Patterns.greet %{name: "Tobi", age: 27, something: :else}
Patterns.greet %{name: "Denis Defreyne"}
Patterns.greet %{name: "Tobi"}
Patterns.greet ["Mop"]
Pattern Matching](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-20-320.jpg)
![defmodule Patterns do
def greet(%{name: name, age: age}) do
IO.puts "Hi there #{name}, what's up at #{age}?"
end
def greet(%{name: "Denis Defreyne"}) do
IO.puts "Hi Denis, are you all set for your talk?"
end
def greet(%{name: name}) do
IO.puts "Hi there #{name}"
end
def greet(_) do
IO.puts "Hi"
end
end
Patterns.greet %{name: "Tobi", age: 27, something: :else}
Patterns.greet %{name: "Denis Defreyne"}
Patterns.greet %{name: "Tobi"}
Patterns.greet ["Mop"]
Pattern Matching](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-21-320.jpg)
![defmodule MyMap do
@doc """
iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
"""
def map(list, function) do
Enum.reverse do_map([], list, function)
end
defp do_map(acc, [], _function) do
acc
end
defp do_map(acc, [head | tail], function) do
do_map([function.(head) | acc], tail, function)
end
end
Doctesting](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-22-320.jpg)
![defmacro plug(plug, opts []) do
quote do
@plugs {unquote(plug), unquote(opts), true}
end
end
Meta Programming](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-23-320.jpg)
![defprotocol Blank do
@doc "Returns true if data is considered blank/empty"
def blank?(data)
end
defimpl Blank, for: List do
def blank?([]), do: true
def blank?(_), do: false
end
defimpl Blank, for: Map do
def blank?(map), do: map_size(map) == 0
end
defimpl Blank, for: Atom do
def blank?(false), do: true
def blank?(nil), do: true
def blank?(_), do: false
end
Polymorphism](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-24-320.jpg)
![defprotocol Blank do
@doc "Returns true if data is considered blank/empty"
def blank?(data)
end
defimpl Blank, for: List do
def blank?([]), do: true
def blank?(_), do: false
end
defimpl Blank, for: Map do
def blank?(map), do: map_size(map) == 0
end
defimpl Blank, for: Atom do
def blank?(false), do: true
def blank?(nil), do: true
def blank?(_), do: false
end
Polymorphism](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-25-320.jpg)
![defprotocol Blank do
@doc "Returns true if data is considered blank/empty"
def blank?(data)
end
defimpl Blank, for: List do
def blank?([]), do: true
def blank?(_), do: false
end
defimpl Blank, for: Map do
def blank?(map), do: map_size(map) == 0
end
defimpl Blank, for: Atom do
def blank?(false), do: true
def blank?(nil), do: true
def blank?(_), do: false
end
Polymorphism](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-26-320.jpg)
![defmodule Plug do
@type opts :: tuple | atom | integer | float | [opts]
@callback init(opts) :: opts
@callback call(Plug.Conn.t, opts) :: Plug.Conn.t
end
“Interfaces”](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-29-320.jpg)
![defmodule Plug do
@type opts :: tuple | atom | integer | float | [opts]
@callback init(opts) :: opts
@callback call(Plug.Conn.t, opts) :: Plug.Conn.t
end
“Interfaces”](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-30-320.jpg)
![defmodule Plug.Head do
@behaviour Plug
alias Plug.Conn
def init([]), do: []
def call(%Conn{method: "HEAD"} = conn, []) do
%{conn | method: "GET"}
end
def call(conn, []), do: conn
end
“Interfaces”](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-31-320.jpg)
![defmodule Plug.Head do
@behaviour Plug
alias Plug.Conn
def init([]), do: []
def call(%Conn{method: "HEAD"} = conn, []) do
%{conn | method: "GET"}
end
def call(conn, []), do: conn
end
“Interfaces”](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-32-320.jpg)
![2.2.2 :001 > [1, 2, 3, 4].map { |i| i + 1 }
=> [2, 3, 4, 5]
iex(2)> Enum.map [1, 2, 3, 4], fn(i) -> i + 1 end
[2, 3, 4, 5]
vs
Where to call functions](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-37-320.jpg)
![scope "/", Rumbl do
pipe_through :browser
get "/", PageController, :index
resources "/users", UserController,
only: [:index, :show, :new, :create]
resources "/sessions", SessionController,
only: [:new, :create, :delete]
get "/watch/:id", WatchController, :show
end
Routes](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-57-320.jpg)
![scope "/", Rumbl do
pipe_through :browser
get "/", PageController, :index
resources "/users", UserController,
only: [:index, :show, :new, :create]
resources "/sessions", SessionController,
only: [:new, :create, :delete]
get "/watch/:id", WatchController, :show
end
Routes](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-58-320.jpg)
![pipeline :browser do
plug :accepts, ["html"]
plug :fetch_session
plug :fetch_flash
plug :protect_from_forgery
plug :put_secure_browser_headers
plug Rumbl.Auth, repo: Rumbl.Repo
end
pipeline :api do
plug :accepts, ["json"]
end
Pipelines](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-59-320.jpg)
![def new_changeset(model, params %{}) do
model
|> cast(params, ~w(name username), [])
|> unique_constraint(:username)
|> validate_length(:username, min: 1, max: 20)
end
def registration_changeset(model, params) do
model
|> new_changeset(params)
|> cast(params, ~w(password), [])
|> validate_length(:password, min: 6, max: 100)
|> put_pass_hash()
end
Changesets](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-65-320.jpg)
![defmodule Rumbl.VideoChannel do
use Rumbl.Web, :channel
def join("videos:" <> video_id, _params, socket) do
{:ok, socket}
end
def handle_in("new_annotation", params, socket) do
broadcast! socket, "new_annotation", %{
user: %{username: "anon"},
body: params["body"],
at: params["at"]
}
{:reply, :ok, socket}
end
end
Channels](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-67-320.jpg)
![iex(17)> user = Repo.preload(user, :videos)
iex(18)> user.videos
[%Rumbl.Video{__meta__: #Ecto.Schema.Metadata<:loaded>,
category: #Ecto.Association.NotLoaded<association
:category is not loaded>,
category_id: nil, description: "such great many wow", id:
3,
inserted_at: #Ecto.DateTime<2016-02-28T18:42:41Z>, title:
"Hubidubiee",
updated_at: #Ecto.DateTime<2016-02-28T18:42:41Z>, url:
"www.lol.com",
user: #Ecto.Association.NotLoaded<association :user is
not loaded>,
user_id: 5}]
Explicit preloading](https://image.slidesharecdn.com/codemotionberlin-161025070200/85/Elixir-Phoenix-fast-concurrent-and-explicit-72-320.jpg)
Elixir & Phoenix – fast, concurrent and explicit
- 7. Elixir and Phoenix fast, concurrent and explicit Tobias Pfeiffer @PragTob pragtob.info
- 8. Elixir and Phoenix fast, concurrent and explicit Tobias Pfeiffer @PragTob pragtob.info
- 10. Platform
- 11. defmodule MyMap do @doc """ iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] """ def map(list, function) do Enum.reverse do_map([], list, function) end defp do_map(acc, [], _function) do acc end defp do_map(acc, [head | tail], function) do do_map([function.(head) | acc], tail, function) end end
- 12. defmodule MyMap do @doc """ iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] """ def map(list, function) do Enum.reverse do_map([], list, function) end defp do_map(acc, [], _function) do acc end defp do_map(acc, [head | tail], function) do do_map([function.(head) | acc], tail, function) end end Ruby-like Syntax
- 14. defmodule MyMap do @doc """ iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] """ def map(list, function) do Enum.reverse do_map([], list, function) end defp do_map(acc, [], _function) do acc end defp do_map(acc, [head | tail], function) do do_map([function.(head) | acc], tail, function) end end First-class functions
- 15. defmodule MyMap do @doc """ iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] """ def map(list, function) do Enum.reverse do_map([], list, function) end defp do_map(acc, [], _function) do acc end defp do_map(acc, [head | tail], function) do do_map([function.(head) | acc], tail, function) end end Tail-Call Optimization
- 16. defmodule MyMap do @doc """ iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] """ def map(list, function) do Enum.reverse do_map([], list, function) end defp do_map(acc, [], _function) do acc end defp do_map(acc, [head | tail], function) do do_map([function.(head) | acc], tail, function) end end Pattern Matching
- 17. defmodule Patterns do def greet(%{name: name, age: age}) do IO.puts "Hi there #{name}, what's up at #{age}?" end def greet(%{name: "Denis Defreyne"}) do IO.puts "Hi Denis, are you all set for your talk?" end def greet(%{name: name}) do IO.puts "Hi there #{name}" end def greet(_) do IO.puts "Hi" end end Patterns.greet %{name: "Tobi", age: 27, something: :else} Patterns.greet %{name: "Denis Defreyne"} Patterns.greet %{name: "Tobi"} Patterns.greet ["Mop"] Pattern Matching
- 18. defmodule Patterns do def greet(%{name: name, age: age}) do IO.puts "Hi there #{name}, what's up at #{age}?" end def greet(%{name: "Denis Defreyne"}) do IO.puts "Hi Denis, are you all set for your talk?" end def greet(%{name: name}) do IO.puts "Hi there #{name}" end def greet(_) do IO.puts "Hi" end end Patterns.greet %{name: "Tobi", age: 27, something: :else} Patterns.greet %{name: "Denis Defreyne"} Patterns.greet %{name: "Tobi"} Patterns.greet ["Mop"] Pattern Matching
- 19. defmodule Patterns do def greet(%{name: name, age: age}) do IO.puts "Hi there #{name}, what's up at #{age}?" end def greet(%{name: "Denis Defreyne"}) do IO.puts "Hi Denis, are you all set for your talk?" end def greet(%{name: name}) do IO.puts "Hi there #{name}" end def greet(_) do IO.puts "Hi" end end Patterns.greet %{name: "Tobi", age: 27, something: :else} Patterns.greet %{name: "Denis Defreyne"} Patterns.greet %{name: "Tobi"} Patterns.greet ["Mop"] Pattern Matching
- 20. defmodule Patterns do def greet(%{name: name, age: age}) do IO.puts "Hi there #{name}, what's up at #{age}?" end def greet(%{name: "Denis Defreyne"}) do IO.puts "Hi Denis, are you all set for your talk?" end def greet(%{name: name}) do IO.puts "Hi there #{name}" end def greet(_) do IO.puts "Hi" end end Patterns.greet %{name: "Tobi", age: 27, something: :else} Patterns.greet %{name: "Denis Defreyne"} Patterns.greet %{name: "Tobi"} Patterns.greet ["Mop"] Pattern Matching
- 21. defmodule Patterns do def greet(%{name: name, age: age}) do IO.puts "Hi there #{name}, what's up at #{age}?" end def greet(%{name: "Denis Defreyne"}) do IO.puts "Hi Denis, are you all set for your talk?" end def greet(%{name: name}) do IO.puts "Hi there #{name}" end def greet(_) do IO.puts "Hi" end end Patterns.greet %{name: "Tobi", age: 27, something: :else} Patterns.greet %{name: "Denis Defreyne"} Patterns.greet %{name: "Tobi"} Patterns.greet ["Mop"] Pattern Matching
- 22. defmodule MyMap do @doc """ iex> MyMap.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] """ def map(list, function) do Enum.reverse do_map([], list, function) end defp do_map(acc, [], _function) do acc end defp do_map(acc, [head | tail], function) do do_map([function.(head) | acc], tail, function) end end Doctesting
- 23. defmacro plug(plug, opts []) do quote do @plugs {unquote(plug), unquote(opts), true} end end Meta Programming
- 24. defprotocol Blank do @doc "Returns true if data is considered blank/empty" def blank?(data) end defimpl Blank, for: List do def blank?([]), do: true def blank?(_), do: false end defimpl Blank, for: Map do def blank?(map), do: map_size(map) == 0 end defimpl Blank, for: Atom do def blank?(false), do: true def blank?(nil), do: true def blank?(_), do: false end Polymorphism
- 25. defprotocol Blank do @doc "Returns true if data is considered blank/empty" def blank?(data) end defimpl Blank, for: List do def blank?([]), do: true def blank?(_), do: false end defimpl Blank, for: Map do def blank?(map), do: map_size(map) == 0 end defimpl Blank, for: Atom do def blank?(false), do: true def blank?(nil), do: true def blank?(_), do: false end Polymorphism
- 26. defprotocol Blank do @doc "Returns true if data is considered blank/empty" def blank?(data) end defimpl Blank, for: List do def blank?([]), do: true def blank?(_), do: false end defimpl Blank, for: Map do def blank?(map), do: map_size(map) == 0 end defimpl Blank, for: Atom do def blank?(false), do: true def blank?(nil), do: true def blank?(_), do: false end Polymorphism
- 27. @spec all?(t) :: boolean @spec all?(t, (element -> as_boolean(term))) :: boolean def all?(enumerable, fun fn(x) -> x end) def all?(enumerable, fun) when is_list(enumerable) and is_function(fun, 1) do do_all?(enumerable, fun) end Implemented in itself!
- 28. @spec all?(t) :: boolean @spec all?(t, (element -> as_boolean(term))) :: boolean def all?(enumerable, fun fn(x) -> x end) def all?(enumerable, fun) when is_list(enumerable) and is_function(fun, 1) do do_all?(enumerable, fun) end Optional Type Annotations
- 29. defmodule Plug do @type opts :: tuple | atom | integer | float | [opts] @callback init(opts) :: opts @callback call(Plug.Conn.t, opts) :: Plug.Conn.t end “Interfaces”
- 30. defmodule Plug do @type opts :: tuple | atom | integer | float | [opts] @callback init(opts) :: opts @callback call(Plug.Conn.t, opts) :: Plug.Conn.t end “Interfaces”
- 31. defmodule Plug.Head do @behaviour Plug alias Plug.Conn def init([]), do: [] def call(%Conn{method: "HEAD"} = conn, []) do %{conn | method: "GET"} end def call(conn, []), do: conn end “Interfaces”
- 32. defmodule Plug.Head do @behaviour Plug alias Plug.Conn def init([]), do: [] def call(%Conn{method: "HEAD"} = conn, []) do %{conn | method: "GET"} end def call(conn, []), do: conn end “Interfaces”
- 37. 2.2.2 :001 > [1, 2, 3, 4].map { |i| i + 1 } => [2, 3, 4, 5] iex(2)> Enum.map [1, 2, 3, 4], fn(i) -> i + 1 end [2, 3, 4, 5] vs Where to call functions
- 39. Pipe people = DB.find_customers orders = Orders.for_customers(people) tax = sales_tax(orders, 2013) filing = prepare_filing(tax)
- 40. filing = DB.find_customers |> Orders.for_customers |> sales_tax(2013) |> prepare_filing Pipe
- 42. filing = DB.find_customers |> Orders.for_customers |> sales_tax(2013) |> prepare_filing Pipe
- 44. person = Person.new(attributes) person = do_something(person) insert_in_db(person) Immutable Data
- 49. Testing++
- 50. Readability
- 51. First class actor support
- 52. OTP
- 53. Supervisors
- 54. Umbrella apps
- 56. connection |> endpoint |> router |> pipelines |> controller |> model |> view Flow
- 57. scope "/", Rumbl do pipe_through :browser get "/", PageController, :index resources "/users", UserController, only: [:index, :show, :new, :create] resources "/sessions", SessionController, only: [:new, :create, :delete] get "/watch/:id", WatchController, :show end Routes
- 58. scope "/", Rumbl do pipe_through :browser get "/", PageController, :index resources "/users", UserController, only: [:index, :show, :new, :create] resources "/sessions", SessionController, only: [:new, :create, :delete] get "/watch/:id", WatchController, :show end Routes
- 59. pipeline :browser do plug :accepts, ["html"] plug :fetch_session plug :fetch_flash plug :protect_from_forgery plug :put_secure_browser_headers plug Rumbl.Auth, repo: Rumbl.Repo end pipeline :api do plug :accepts, ["json"] end Pipelines
- 60. def new(conn, _params) do changeset = User.new_changeset(%User{}) render conn, "new.html", changeset: changeset end Controller
- 61. defmodule Rumbl.User do use Rumbl.Web, :model schema "users" do field :name, :string field :username, :string field :password, :string, virtual: true field :password_hash, :string has_many :videos, Rumbl.Video timestamps end # ... end Model
- 62. defmodule Rumbl.UserView do use Rumbl.Web, :view alias Rumbl.User def first_name(%{name: name}) do name |> String.split(" ") |> Enum.at(0) end end View
- 63. <%= form_for @changeset, user_path(@conn, :create), fn form -> %> <div class="form-group"> <%= text_input form, :name, placeholder: "Name", class: "form-control" %> <%= error_tag form, :name %> </div> <div class="form-group"> <%= text_input form, :username, placeholder: "Username", class: "form-control" %> <%= error_tag form, :username %> </div> <div class="form-group"> <%= password_input form, :password, placeholder: "Password", class: "form-control" %> <%= error_tag form, :password %> </div> <%= submit "Create User", class: "btn btn-primary" %> <% end %> Template
- 65. def new_changeset(model, params %{}) do model |> cast(params, ~w(name username), []) |> unique_constraint(:username) |> validate_length(:username, min: 1, max: 20) end def registration_changeset(model, params) do model |> new_changeset(params) |> cast(params, ~w(password), []) |> validate_length(:password, min: 6, max: 100) |> put_pass_hash() end Changesets
- 66. def create(conn, %{"user" => user_params}) do changeset = User.registration_changeset(%User{}, user_params) case Repo.insert changeset do {:ok, user} -> conn |> Rumbl.Auth.login(user) |> put_flash(:info, "You successfully registered!") |> redirect(to: user_path(conn, :index)) {:error, changeset}-> render conn, "new.html", changeset: changeset end end Changesets
- 67. defmodule Rumbl.VideoChannel do use Rumbl.Web, :channel def join("videos:" <> video_id, _params, socket) do {:ok, socket} end def handle_in("new_annotation", params, socket) do broadcast! socket, "new_annotation", %{ user: %{username: "anon"}, body: params["body"], at: params["at"] } {:reply, :ok, socket} end end Channels
- 68. The right tool
- 69. iex(13)> user = Repo.get_by(User, name: "Homer") iex(14)> user.videos #Ecto.Association.NotLoaded<association :videos is not loaded> Explicit preloading
- 70. iex(13)> user = Repo.get_by(User, name: "Homer") iex(14)> user.videos #Ecto.Association.NotLoaded<association :videos is not loaded> Explicit preloading
- 71. iex(15)> Repo.preload(user, :videos) iex(16)> user.videos #Ecto.Association.NotLoaded<association :videos is not loaded> Explicit preloading
- 72. iex(17)> user = Repo.preload(user, :videos) iex(18)> user.videos [%Rumbl.Video{__meta__: #Ecto.Schema.Metadata<:loaded>, category: #Ecto.Association.NotLoaded<association :category is not loaded>, category_id: nil, description: "such great many wow", id: 3, inserted_at: #Ecto.DateTime<2016-02-28T18:42:41Z>, title: "Hubidubiee", updated_at: #Ecto.DateTime<2016-02-28T18:42:41Z>, url: "www.lol.com", user: #Ecto.Association.NotLoaded<association :user is not loaded>, user_id: 5}] Explicit preloading
- 73. So we all go and do Elixir and Phoenix now?
- 74. ❤
- 75. Dirtiness
- 76. Baggage
- 77. Eco-System
- 78. A new land
- 79. So, would you start a new project in Elixir and Phoenix now? Q&A question #1
- 80. IT DEPENDS
- 81. IT DEPENDS
- 82. Thanks & Enjoy Elixir Tobias Pfeiffer @PragTob pragtob.info
- 83. Photo Attribution ● CC BY-ND 2.0 – https://www.flickr.com/photos/mmmswan/8918529543/ ● CC BY 2.0 – https://flic.kr/p/eKGRRJ ● CC BY-NC 2.0 – https://www.flickr.com/photos/-jule/2728475835/ – https://flic.kr/p/emoKPd ● CC BY-NC-ND 2.0 – https://flic.kr/p/eyC7ZT – https://www.flickr.com/photos/75487768@N04/14029339573/ – https://flic.kr/p/bG2r2D ● CC BY-SA 2.0 – https://commons.wikimedia.org/wiki/File:Heckert_GNU_white.svg – https://flic.kr/p/cEJDC3