SOLID e Best Practices
Quem Somos?
Guilherme Guitte (Guitte)Fatec Sorocaba
Desenvolvedor Web
Já trabalhei com Ruby on Rails
Trabalho na Leroy Merlin (Laravel4)
Quem somos?
Luiz Fernando / Zizaco
-
Programador
-
Desenvolvedor web
-
FATEC Sorocaba
- Artigos publicados
-
WebDesigner wannabe
- Leroy Merlin (Laravel4)
- Sempre mais
O que vamos falar hoje?
O que é SOLID?
O que cada letra significa + exemplos
Best Practices
Progressive enhancement
Conclusão
NO Cargo Cult Programming
O que é SOLID?
- Quando falamos de SOLID, na verdade é S.O.L.I.D.
- É uma sigla
- Criado/nomeado por Michael Feathers/Robert C. Martin (Uncle Bob)
- São 5 princípios
O que é solid?
S -> SRP -> Single Responsibility Principle
O -> OCP -> Open-closed Principle
L -> LSP -> Liskov Substitution Principle
I -> ISP -> Interface Segregation Principle
D -> DIP -> Dependecy Inversion Principle
SRP - Single responsibility Principle
"The Single Responsibility Principle states that a class should have one, and only one, reason to change. "
Exemplo - errado
<?php
class Product extends Eloquent
{
static public function last() {...}
public function getPrice() {...}
public function getImageUrl() {...}
public function processImage() {...}
static public function exportAll() {...}
public function hasValidName() {...}
public function isValid() {...}
}
EXEMPLO - Certo
<?php
class Product extends Eloquent
{
public function __construct(ProductValidator $validator) {...}
public function getPrice() {...}
public function getImageUrl() {...}
public function isValid() {...} // Uses $this->validator
/** static public function last() {...} **/
/** public function processImage() {...} **/
/** static public function exportAll() {...} **/
/** public function hasValidName() {...} **/
}
class ImageProcessor
{
public function processImage(Product $product) {...}
}
OCP - Open closed Principle
"The Open Closed principle of SOLID design states that code is open for extension but closed for modification."
Exemplo - Errado
<?php
class Product extends Eloquent
{
public function getPrice() {
switch ($this->type) {
case 'kit':
// ...
break;
default:
// ...
break;
}
}
}
class Report
{
public function Report(Product $product) {
...
$product->getPrice();
...
}
}
Exemplo - certo
<?php
class Product extends Eloquent
{
public function getPrice() {...}
}
class ProductKit extends Product
{
public function getPrice() {...}
}
class Report
{
public function Report(Product $product) {
...
$product->getPrice();
...
}
}
LSP - Liskov Substitution Principle
"This principle states that objects should be replaceable with instances of their subtypes without altering the correctness of that program. "
Exemplo
<?php
Cache::put('foo', 'bar', 5);
Cache::get('foo', null);
Mail::send('emails.hiho', $data, function($message) {
$message->to('zizaco@gmail.com', 'Zizaco')
->subject('Hiho!');
});
ISP - Interface Segregation Principle
"This principle states that no implementation of an interface should be forced to depend on methods it does not use. "
Exemplo - Errado
<?php
// NO CARGO CULT!!!!
interface ProductInterface
{
static public function last();
public function getPrice();
public function getImageUrl();
public function processImage();
static public function exportAll();
public function hasValidName();
public function isValid();
}
Exemplo - certo
<?php
interface ProductInterface
{
public function getPrice();
public function isValid();
}
interface HasImageInterface
{
public function getImageUrl();
}
Dependency Inversion Principle
"This principle states that high-level code should not depend on low-level code, and that abstractions should not depend upon details. "
Exemplo - Errado
<?php
class Product extends Eloquent
{
public function isValid()
{
$validator = new ProductValidator;
return $validator->validate($product);
}
}
class ProductValidator
{
public function validate(Product $product) {...}
}
Exemplo - Certo
<?php
class Product implements ProductInterface
{
protected $validator;
public function __construct(ValidatorInterface $validator)
{
$this->validator = $validator;
}
public function isValid()
{
return $this->validator->validate($product);
}
}
class ProductValidator implements ValidatorInterface
{
public function validate(ProductInterface $product)
}
Agora entendi...
Tudo faz sentido...
Quer dizer que agora sei tudo sobre SOLID?
Sim/não
Agora mão na massa!!
Progressive enhancement
Again, No Cargo Cult Programming
Conclusão
Links:
https://leanpub.com/laravel
Merchan:
Pulse:
https://github.com/Zizaco/pulse