Simple Navigation Iterator (Fun With Iterators)

RecursiveNavigationIterator

<?php
/**
* RecursiveNavigationIterator
*/
class RecursiveNavigationIterator extends RecursiveIteratorIterator
{
    public $openTag = "<ul>\n";

    public $closeTag = "</ul>\n";

    public function beginIteration()
    {
        echo str_repeat("\t", $this->getDepth());
        echo $this->openTag;
    }

    public function endIteration()
    {
        echo str_repeat("\t", $this->getDepth());
        echo $this->closeTag;
    }

    public function beginChildren()
    {
        echo str_repeat("\t", $this->getDepth());
        echo $this->openTag;
    }

    public function endChildren()
    {
        echo str_repeat("\t", $this->getDepth());
        echo $this->closeTag;
    }

    public function current()
    {
        if ($this->getInnerIterator()->hasChildren()) {
            return $this->key();
        }

        return $this->getInnerIterator()->current();
    }
}

$it = new RecursiveArrayIterator([
    'Home',
    'About' => ['Careers', 'Contact'],
    'Location',
    'FAQ',
]);

$navIt = new RecursiveNavigationIterator($it, RecursiveIteratorIterator::SELF_FIRST);
foreach ($navIt as $navItem) {
    echo str_repeat("\t", $navIt->getDepth() + 1);
    echo "<li>{$navItem}</li>\n";
}