/**
* Convert the link to a relative link by substracting a base URI
*
* This is the opposite of resolving a relative link - i.e. creating a
* relative reference link from an original URI and a base URI.
*
* If the two URIs do not intersect (e.g. the original URI is not in any
* way related to the base URI) the URI will not be modified.
*
* @param Uri|string $baseUri
* @return Uri
*/
public function makeRelative($baseUri)
{
// Copy base URI, we should not modify it
$baseUri = new static($baseUri);
$this->normalize();
$baseUri->normalize();
$host = $this->getHost();
$baseHost = $baseUri->getHost();
if ($host && $baseHost && $host != $baseHost) {
// Not the same hostname
return $this;
}
$port = $this->getPort();
$basePort = $baseUri->getPort();
if ($port && $basePort && $port != $basePort) {
// Not the same port
return $this;
}
$scheme = $this->getScheme();
$baseScheme = $baseUri->getScheme();
if ($scheme && $baseScheme && $scheme != $baseScheme) {
// Not the same scheme (e.g. HTTP vs. HTTPS)
return $this;
}
// Remove host, port and scheme
$this->setHost(null)->setPort(null)->setScheme(null);
// Is path the same?
if ($this->getPath() == $baseUri->getPath()) {
$this->setPath('');
return $this;
}
$pathParts = preg_split('|(/)|', $this->getPath(), null, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
$baseParts = preg_split('|(/)|', $baseUri->getPath(), null, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
// Get the intersection of existing path parts and those from the
// provided URI
$matchingParts = array_intersect_assoc($pathParts, $baseParts);
// Loop through the matches
foreach ($matchingParts as $index => $segment) {
// If we skip an index at any point, we have parent traversal, and
// need to prepend the path accordingly
if ($index && !isset($matchingParts[$index - 1])) {
array_unshift($pathParts, '../');
continue;
}
// Otherwise, we simply unset the given path segment
unset($pathParts[$index]);
}
// Reset the path by imploding path segments
$this->setPath(implode($pathParts));
return $this;
}
/**
* Transform References
*
* This function implements the "transform references" algorithm from
* the RFC3986 specification for URIs.
*
* @see http://tools.ietf.org/html/rfc3986#page-31
*
* @param string $relative
* @param bool $strict
*
* @return static
*/
public function transformReference($relative, $strict = false)
{
$base = $this;
$relative = new static((string) $relative);
$transformed = new static();
if (!$strict && $relative->getScheme() == $this->getScheme()) {
$relative->setScheme(null);
}
if ($relative->getScheme() !== null) {
$transformed->setScheme($relative->getScheme());
$transformed->setAuthority($relative->getAuthority());
$transformed->setPath(static::remove_dot_segments($relative->getPath()));
$transformed->setQuery($relative->getQuery());
} else {
if ($relative->getAuthority() !== null) {
$transformed->setAuthority($relative->getAuthority());
$transformed->setPath(static::remove_dot_segments($relative->getPath()));
$transformed->setQuery($relative->getQuery());
} else {
if ($relative->getPath() == '') {
$transformed->setPath($base->getPath());
if ($relative->getQuery() !== null) {
$transformed->setQuery($relative->getQuery());
} else {
$transformed->setQuery($base->getQuery());
}
} else {
if ('/' == substr($relative->getPath(), 0, 1)) {
$transformed->setPath(static::remove_dot_segments($relative->getPath()));
} else {
$transformed->setPath(static::merge($base->getPath(), $relative->getPath()));
$transformed->setPath(static::remove_dot_segments($transformed->getPath()));
}
$transformed->setQuery($relative->getQuery());
}
$transformed->setAuthority($base->getAuthority());
}
$transformed->setScheme($base->getScheme());
}
$transformed->setFragment($relative->getFragment());
return $transformed;
}
