ELIXIR-VIDEO-11
Books
defmodule Servidor.Book do
defstruct id: 0, title: "", author: "", year: 0, pages: 0
end
defmodule Servidor.BooksApi do
alias Servidor.Book
def books do
[
%Book{
id: 1,
title: "O homem que calculava",
author: "Malba Tahan",
year: 1993,
pages: 250
},
%Book{
id: 2,
title: "A arte de ser um perfeito mau professor",
author: "Malba Tahan",
year: 1967,
pages: 122
},
%Book{
id: 3,
title: "Acordaram-me de madrugada",
author: "Malba Tahan",
year: 1973,
pages: 318
},
%Book{
id: 4,
title: "Antologia da matemática",
author: "Malba Tahan",
year: 1960,
pages: nil
},
%Book{
id: 5,
title: "Belezas e maravilhas do céu",
author: "Malba Tahan",
year: 1974,
pages: 205
},
%Book{
id: 6,
title: "Didática da matemática",
author: "Malba Tahan",
year: 1961,
pages: nil
},
%Book{
id: 7,
title: "A lógica na matemática",
author: "Malba Tahan",
year: 1966,
pages: 183
},
%Book{
id: 8,
title: "Matematica, Curiosa y Divertida",
author: "Malba Tahan",
year: 2006,
pages: nil
},
%Book{
id: 9,
title: "Matemática divertida e delirante",
author: "Malba Tahan",
year: 1962,
pages: 266
},
%Book{
id: 10,
title: "A matemática na lenda e na história",
author: "Malba Tahan",
year: 1974,
pages: 225
},
%Book{
id: 11,
title: "The Lord of the Rings",
author: "J.R.R. Tolkien",
year: 1954,
pages: 1193
},
%Book{
id: 12,
title: "The fellowship of the ring",
author: "J.R.R. Tolkien",
year: 1954,
pages: 498
},
%Book{
id: 13,
title: "The Two Towers",
author: "J.R.R. Tolkien",
year: 1954,
pages: 438
},
%Book{
id: 14,
title: "The Hobbit",
author: "J.R.R. Tolkien",
year: 1937,
pages: 310
},
%Book{
id: 15,
title: "The Return of the King",
author: "J.R.R. Tolkien",
year: 1950,
pages: 500
},
%Book{
id: 16,
title: "Novels (Hobbit / Lord of the Rings)",
author: "J.R.R. Tolkien",
year: 1979,
pages: 1601
},
%Book{
id: 17,
title: "The Silmarillion",
author: "J.R.R. Tolkien",
year: 1977,
pages: 432
},
%Book{
id: 18,
title: "Insomnia",
author: "Stephen King",
year: 1994,
pages: 740
},
%Book{
id: 19,
title: "The Hobbit",
author: "Charles Dixon",
year: 1990,
pages: 144
},
%Book{
id: 20,
title: "The Children of Húrin",
author: "J.R.R. Tolkien",
year: 2001,
pages: 313
},
%Book{
id: 21,
title: "And Then There Were None",
author: "Agatha Christie",
year: 1939,
pages: 240
},
%Book{
id: 22,
title: "Murder on the Orient Express",
author: "Agatha Christie",
year: 1933,
pages: 253
},
%Book{
id: 23,
title: "The Murder of Roger Ackroyd",
author: "Agatha Christie",
year: 1926,
pages: 256
},
%Book{
id: 24,
title: "The A.B.C. Murders",
author: "Agatha Christie",
year: 1936,
pages: 232
},
%Book{
id: 25,
title: "Curtain",
author: "Agatha Christie",
year: 1975,
pages: 238
},
%Book{
id: 26,
title: "Insomnia",
author: "Stephen King",
year: 1994,
pages: 740
},
%Book{
id: 27,
title: "The Bachman Books (Long Walk / Rage / Roadwork / Running Man)",
author: "Stephen King",
year: 1985,
pages: 880
},
%Book{
id: 28,
title: "The Murder at the Vicarage",
author: "Agatha Christie",
year: 1930,
pages: 253
},
%Book{
id: 29,
title: "The Mysterious Affair at Styles",
author: "Agatha Christie",
year: 1920,
pages: 222
},
%Book{
id: 30,
title: "The Big Four",
author: "Agatha Christie",
year: 1927,
pages: 224
}
]
end
end
defmodule Servidor.BooksController do
def book_item(book) do
"\nId: #{book.id}/ Título: #{book.title}/ Autor: #{book.author}"
end
end
Comprehension
# numeros = [1, 2, 3, 4, 5]
# letras = ["a", "b", "c"]
# for x <- numeros, y <- numeros, z <- letras do
# {x , y, z}
# end
books = Servidor.BooksApi.books()
# for book <- books, do: book.title
# for book <- books, do: {book.title, book.author}
# for book <- books, do: %{title: book.title, author: book.author}
Comprehension / pattern matching
# for %{author: "J.R.R. Tolkien"} = book <- books do
# %{t: book.title, a: book.author}
# end
# for %{author: "Agatha Christie"} = book <- books, do: %{t: book.title, a: book.author}
for %{author: "Malba Tahan", title: title} = _book <- books, do: %{t: title}
Comprehension / filter
# Enum.filter(books, fn book -> book.id == 1 end)
# for book <- books, book.id == 1, do: %{t: book.title}
for book <- books, book.author == "Stephen King", do: %{t: book.title}
Comprehension / filter function
sk? = fn author -> author == "Stephen King" end
ac? = fn author -> author == "Agatha Christie" end
mt? = fn author -> author == "Malba Tahan" end
jk? = fn author -> author == "J.R.R. Tolkien" end
# for book <- books, sk?.(book.author), do: %{a: book.author, t: book.title}
# for book <- books, ac?.(book.author), do: %{a: book.author, t: book.title}
# for book <- books, mt?.(book.author), do: %{a: book.author, t: book.title}
# for book <- books, jk?.(book.author), do: %{a: book.author, t: book.title}
# for book <- books, jk?.(book.author) || mt?.(book.author), do: %{a: book.author, t: book.title}
# for book <- books, !jk?.(book.author), do: %{a: book.author, t: book.title}
EEx
# EEx.eval_string "Hi, <%= @name %>", assigns: [name: "Roger"]
html = "Os livros do <%= @name %> (<%= 10 + 20 %>)
"
EEx.eval_string html, assigns: [name: "Roger"]
EEx / inspect
html = """
Os livros do <%= @name %>
<%= inspect(@books) %>
"""
result = EEx.eval_string(html, assigns: [name: "Roger", books: books])
IO.puts(result)
EEx / comprehension
html = """
Os livros do <%= @name %>
<%= for book <- @books do %>
<%= book.author %> / <%= book.title %>
<% end %>
by Elixir
"""
result = EEx.eval_string(html, assigns: [name: "João", books: books])
IO.puts(result)
EEx / comprehension com filtro
html = """
Os livros do <%= @name %>
Autor: <%= @autor %>
<%= for book <- @books, book.author == @autor do %>
<%= book.title %>
<% end %>
"""
result =
EEx.eval_string(html,
assigns: [
name: "Roger",
autor: "Malba Tahan",
books: books
]
)
IO.puts(result)
EEx / com função externa
# usando função externa
html = """
Os livros do <%= @name %>
Autor: <%= @autor %>
<%= for book <- @books, book.author == @autor do %>
<%= Servidor.BooksController.book_item(book) %>
<% end %>
"""
result =
EEx.eval_string(html,
assigns: [
name: "Roger",
autor: "Malba Tahan",
books: books
]
)
IO.puts(result)
