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Dominik Liebler
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Merge remote-tracking branch 'memsb/master'
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‎README.md

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@@ -41,6 +41,7 @@ The patterns can be structured in roughly three different categories. Please cli
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* [Mediator](Mediator) [:notebook:](http://en.wikipedia.org/wiki/Mediator_pattern)
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* [NullObject](NullObject) [:notebook:](http://en.wikipedia.org/wiki/Null_Object_pattern)
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* [Observer](Observer) [:notebook:](http://en.wikipedia.org/wiki/Observer_pattern)
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* [Specification](Specification) [:notebook:](http://en.wikipedia.org/wiki/Specification_pattern)
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* [State](State) [:notebook:](http://en.wikipedia.org/wiki/State_pattern)
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* [Strategy](Strategy) [:notebook:](http://en.wikipedia.org/wiki/Strategy_pattern)
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* [TemplateMethod](TemplateMethod) [:notebook:](http://en.wikipedia.org/wiki/Template_method_pattern)

‎Specification/AbstractSpecification.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* An abstract specification allows the creation of wrapped specifications
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*/
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abstract class AbstractSpecification implements SpecificationInterface
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{
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/**
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* Checks if given item meets all criteria
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*
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* @param Item $item
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*
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* @return bool
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*/
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public function isSatisfiedBy(Item $item)
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{
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}
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/**
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* Creates a new logical AND specification
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*
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* @param SpecificationInterface $spec
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*
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* @return SpecificationInterface
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*/
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public function plus(SpecificationInterface $spec)
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{
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return new Plus($this, $spec);
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}
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/**
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* Creates a new logical OR composite specification
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*
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* @param SpecificationInterface $spec
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*
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* @return SpecificationInterface
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*/
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public function either(SpecificationInterface $spec)
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{
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return new Either($this, $spec);
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}
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/**
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* Creates a new logical NOT specification
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*
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* @return SpecificationInterface
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*/
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public function not()
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{
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return new Not($this);
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}
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}

‎Specification/Either.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* A logical AND specification
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*/
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class Either extends AbstractSpecification
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{
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protected $left;
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protected $right;
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/**
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* A composite wrapper of two specifications
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*
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* @param SpecificationInterface $left
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* @param SpecificationInterface $right
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*/
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public function __construct(SpecificationInterface $left, SpecificationInterface $right)
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{
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$this->left = $left;
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$this->right = $right;
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}
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/**
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* Returns the evaluation of both wrapped specifications as a logical AND
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*
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* @param Item $item
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*
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* @return bool
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*/
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public function isSatisfiedBy(Item $item)
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{
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return $this->left->isSatisfiedBy($item) || $this->right->isSatisfiedBy($item);
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}
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}

‎Specification/Item.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* An trivial item
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*/
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class Item
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{
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protected $price;
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/**
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* An item must have a price
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*
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* @param int $price
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*/
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public function __construct($price)
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{
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$this->price = $price;
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}
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/**
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* Get the items price
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*
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* @return int
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*/
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public function getPrice()
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{
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return $this->price;
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}
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}

‎Specification/Not.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* A logical Not specification
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*/
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class Not extends AbstractSpecification
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{
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protected $spec;
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/**
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* Creates a new specification wrapping another
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*
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* @param SpecificationInterface $spec
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*/
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public function __construct(SpecificationInterface $spec)
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{
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$this->spec = $spec;
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}
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/**
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* Returns the negated result of the wrapped specification
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*
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* @param Item $item
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*
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* @return bool
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*/
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public function isSatisfiedBy(Item $item)
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{
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return !$this->spec->isSatisfiedBy($item);
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}
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}

‎Specification/Plus.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* A logical AND specification
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*/
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class Plus extends AbstractSpecification
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{
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protected $left;
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protected $right;
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/**
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* Creation of a locical AND of two specifications
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*
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* @param SpecificationInterface $left
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* @param SpecificationInterface $right
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*/
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public function __construct(SpecificationInterface $left, SpecificationInterface $right)
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{
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$this->left = $left;
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$this->right = $right;
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}
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/**
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* Checks if the composite AND of specifications passes
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*
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* @param Item $item
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*
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* @return bool
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*/
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public function isSatisfiedBy(Item $item)
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{
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return $this->left->isSatisfiedBy($item) && $this->right->isSatisfiedBy($item);
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}
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}

‎Specification/PriceSpecification.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* A specification to check an Item is priced between min and max
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*/
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class PriceSpecification extends AbstractSpecification
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{
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protected $maxPrice;
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protected $minPrice;
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/**
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* Sets the optional maximum price
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*
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* @param int $maxPrice
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*/
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public function setMaxPrice($maxPrice)
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{
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$this->maxPrice = $maxPrice;
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}
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/**
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* Sets the optional minimum price
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*
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* @param int $minPrice
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*/
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public function setMinPrice($minPrice)
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{
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$this->minPrice = $minPrice;
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}
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/**
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* Checks if Item price falls between bounds
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*
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* @param Item $item
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*
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* @return bool
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*/
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public function isSatisfiedBy(Item $item)
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{
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if ( !empty($this->maxPrice) && $item->getPrice() > $this->maxPrice) {
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return false;
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}
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if ( !empty($this->minPrice) && $item->getPrice() < $this->minPrice) {
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return false;
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}
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return true;
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}
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}

‎Specification/SpecificationInterface.php

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<?php
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namespace DesignPatterns\Specification;
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/**
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* An interface for a specification
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*/
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interface SpecificationInterface
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{
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/**
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* A boolean evaluation indicating if the object meets the specification
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*
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* @param Item $item
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*
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* @return bool
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*/
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public function isSatisfiedBy(Item $item);
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/**
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* Creates a logical AND specification
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*
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* @param SpecificationInterface $spec
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*/
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public function plus(SpecificationInterface $spec);
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/**
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* Creates a logical OR specification
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*
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* @param SpecificationInterface $spec
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*/
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public function either(SpecificationInterface $spec);
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/**
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* Creates a logical not specification
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*/
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public function not();
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}

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