Version of Sitemap\Url

Sitemap\Url.php

<?php
namespace Sitemap;

/**
 * Basic sitemap URL class.
 */
class Url extends UrlAbstract
{
    /**
     * Valid values of "changefreq" element.
     */
    const ALWAYS = 'always';
    const HOURLY = 'hourly';
    const DAILY = 'daily';
    const WEEKLY = 'weekly';
    const MONTHLY = 'monthly';
    const YEARLY = 'yearly';
    const NEVER = 'never';

    /**
     * @var string The date of last modification of the document.
     */
    private $lastmod;
    /**
     * @var string How frequently the page is likely to change.
     */
    private $changefreq;
    /**
     * @var string The priority of this URL relative to other URLs on site.
     */
    private $priority;
    
    /**
     * Returns valid values of "changefreq" element.
     * @return array
     */
    public function getValidFrequencies()
    {
        return array(
            self::ALWAYS,
            self::HOURLY,
            self::DAILY,
            self::WEEKLY,
            self::MONTHLY,
            self::YEARLY,
            self::NEVER
        );
    }
    
    /**
     * Sets "lastmod" element.
     * @param string|int $date
     * @return self
     */
    private function setLastmod($date)
    {
        $this->lastmod = date('c', $date);

        return $this;
    }

    /**
     * Sets "changefreq" element.
     * @param string $frequency
     * @return self
     * @throws \InvalidArgumentException
     */
    private function setChangefreq($frequency)
    {
        if (!in_array($frequency, $this->getValidFrequencies(), true)) {
            throw new \InvalidArgumentException(
                'Invalid value (' . $frequency . ') of "changefreq" element.'
            );
        }
        $this->changefreq = $frequency;

        return $this;
    }

    /**
     * Sets "priority" element.
     * @param string|float $priority
     * @return self
     * @throws \InvalidArgumentException
     */
    private function setPriority($priority)
    {
        if (!is_numeric($priority) || $priority < 0 || $priority > 1) {
            throw new \InvalidArgumentException(
                'Invalid value (' . $priority . ') of "priority" element.'
            );
        }
        $this->priority = number_format($priority, 1, '.', '');

        return $this;
    }
}

Sitemap\UrlInterface.php

<?php
namespace Sitemap;

/**
 * Sitemap URL interface.
 * @see http://sitemaps.org/protocol.html#xmlTagDefinitions
 */
interface UrlInterface
{
    const MAX_URL_LENGTH = 2047;

    /**
     * Url constructor.
     * @param string $location location item URL
     * @param array $optional optional elements\tags
     */
    public function __construct($location, array $optional = array());

    /**
     * Get values of sub elements\tags.
     * @return array Pairs of tag => value.
     */
    public function getElements();
}

UrlAbstract.php

<?php
namespace Sitemap;

/**
 * Abstract sitemap URL.
 */
abstract class UrlAbstract implements UrlInterface
{
    /**
     * @var string
     */
    private $urlString;
    /**
     * @var string URL of the page.
     */
    private $loc;

    /**
     * Url constructor.
     * @param string $location location item URL
     * @param array $optional optional elements\tags
     * @throws \InvalidArgumentException
     */
    public function __construct($location, array $optional = array())
    {
        if (false === filter_var($location, FILTER_VALIDATE_URL)) {
            throw new \InvalidArgumentException(
                'The location URL "' . $location . '" is invalid.'
            );
        }
        if (mb_strlen($location, 'UTF-8') > self::MAX_URL_LENGTH) {
            throw new \InvalidArgumentException(
                'The location must be less than ' . (self::MAX_URL_LENGTH + 1) . ' characters.'
            );
        }
        $this->loc = $location;
        
        foreach ($optional as $property => $value) {
            if (!property_exists($this, $property)) {
                throw new \InvalidArgumentException(
                    'Element "' . $property . '" not defined.'
                );
            }
            
            $method = 'set' . ucfirst($property);
            if (!method_exists($this, $method)) {
                throw new \InvalidArgumentException(
                    'Element "' . $property . '" not writable.'
                );
            }
            $this->{$method}($value);
        }
    }

    /**
     * Get values of elements\tags.
     * @return array Pairs of tag => value.
     */
    public function getElements()
    {
        return get_object_vars($this);
    }
    
    /**
     * 
     * @return string
     */
    public function __toSring()
    {
        if ($this->urlString !== null) {
            $writer = new \XMLWriter;
            $writer->openMemory();
            $writer->startElement('url');
            foreach ($this->getElements() as $name => $value) {
                $writer->writeElement($name, $value);
            }
            $writer->endElement();
            $this->urlString = (string)$writer->flush();
        }
        return $this->urlString;
    )
}