DesignPatternsPHP/Specification/PriceSpecification.php

<?php
namespace DesignPatterns\Specification;

/**
 * A specification to check an Item is priced between min and max
 */
class PriceSpecification extends AbstractSpecification
{
    protected $maxPrice;
    protected $minPrice;

    /**
     * Sets the optional maximum price
     *
     * @param int $maxPrice
     */
    public function setMaxPrice($maxPrice)
    {
        $this->maxPrice = $maxPrice;
    }

    /**
     * Sets the optional minimum price
     *
     * @param int $minPrice
     */
    public function setMinPrice($minPrice)
    {
        $this->minPrice = $minPrice;
    }

    /**
     * Checks if Item price falls between bounds
     * 
     * @param Item $item
     * 
     * @return bool
     */
    public function isSatisfiedBy(Item $item)
    {
        if ( !empty($this->maxPrice) && $item->getPrice() > $this->maxPrice) {
            return false;
        }
        if ( !empty($this->minPrice) && $item->getPrice() < $this->minPrice) {
            return false;
        }

        return true;
    }
}