dateperiod-iterator.php

<?php
/*
 * Get all 52 weeks of the year and work days given the first day of the January of current year
 * @link http://stackoverflow.com/a/14147613/367456 
 * @author hakre <http://hakre.wordpress.com/credits>
 */

/**
 * Filter a DatePeriod by year
 */
class DatePeriodYearFilter extends FilterIterator
{
    private $year;

    public function __construct(DatePeriod $period, $year) {

        $this->year = $year;
        parent::__construct(new IteratorIterator($period));
    }

    public function accept() {

        return $this->current()->format('Y') == $this->year;
    }
}

/**
 * Iterator that iterates over the first and last element of
 * an Iterator
 */
class FirstAndLastIterator extends CachingIterator
{
    public function __construct(Iterator $iterator) {

        parent::__construct($iterator, self::TOSTRING_USE_KEY);
    }

    public function next() {

        while (parent::hasNext()) {
            parent::next();
        }
    }
}