絶対URLをもとに相対URLから絶対URLを生成

hoge.php

<?php
/**
 * 絶対パスの取得
 *
 * @param  string $base
 * @param  string $absolute
 * @return string
 */
function getHttpPath($base, $absolute)
{
    $uri = Zend_Uri_Http::fromString($base);
    $absolute = str_replace(' ', '%20', trim($absolute));
    if (strpos($absolute, '//') === 0) { // //example.com -> http://example.com
        $absolute = $uri->getScheme() . ':' . $absolute;
    }
    if (strpos($absolute, '/') === 0) { // /path -> http://example.com/path
        $absolute = $uri->getScheme() . '://' . $uri->getHost() . $absolute;
    }
    if (Zend_Uri_Http::check($absolute) || preg_match('/^(javascript|mailto|device|tel):/i', $absolute)) {
        return $absolute;
    }
    if (($pos = strpos($absolute, '#')) !== false) { // #fragment
        $uri->setFragment(substr($absolute, $pos + 1));
        $absolute = substr($absolute, 0, $pos);
    }
    list($absolute, $query) = explode('?', $absolute . '?'); // ?query
    $uri->setQuery($query);
    $path = str_replace('//', '/', $uri->getPath()); // /foo//bar/hoge -> /foo/bar/hoge
    if (strrpos($path, '/') !== 0) { // exists /foo/bar/hoge
        $path = explode('/', substr($path, 1, strrpos($path, '/') - 1)); // /foo/bar/hoge -> array('foo', 'bar')
    } else {
        $path = array();
    }
    $list = explode('/', $absolute);
    foreach ($list as $part) {
        if (in_array($part, array('', '.'))) {
            continue;
        }
        if (preg_match('/^\.+$/', $part)) {
            array_pop($path);
        } else {
            $path[] = $part;
        }
    }
    $uri->setPath('/' . implode('/', $path) . ((count($path) && substr($absolute, -1) === '/') ? '/' : ''));
    return $uri->getUri();
}