<?php
namespace GuzzleHttp\Psr7;
use Psr\Http\Message\UriInterface;
/**
* Provides methods to normalize and compare URIs.
*
* @author Tobias Schultze
*
* @link https://tools.ietf.org/html/rfc3986#section-6
*/
final class UriNormalizer
{
/**
* Default normalizations which only include the ones that preserve semantics.
*
* self::CAPITALIZE_PERCENT_ENCODING | self::DECODE_UNRESERVED_CHARACTERS | self::CONVERT_EMPTY_PATH |
* self::REMOVE_DEFAULT_HOST | self::REMOVE_DEFAULT_PORT | self::REMOVE_DOT_SEGMENTS
*/
const PRESERVING_NORMALIZATIONS = 63;
/**
* All letters within a percent-encoding triplet (e.g., "%3A") are case-insensitive, and should be capitalized.
*
* Example: http://example.org/a%c2%b1b → http://example.org/a%C2%B1b
*/
const CAPITALIZE_PERCENT_ENCODING = 1;
/**
* Decodes percent-encoded octets of unreserved characters.
*
* For consistency, percent-encoded octets in the ranges of ALPHA (%41–%5A and %61–%7A), DIGIT (%30–%39),
* hyphen (%2D), period (%2E), underscore (%5F), or tilde (%7E) should not be created by URI producers and,
* when found in a URI, should be decoded to their corresponding unreserved characters by URI normalizers.
*
* Example: http://example.org/%7Eusern%61me/ → http://example.org/~username/
*/
const DECODE_UNRESERVED_CHARACTERS = 2;
/**
* Converts the empty path to "/" for http and https URIs.
*
* Example: http://example.org → http://example.org/
*/
const CONVERT_EMPTY_PATH = 4;
/**
* Removes the default host of the given URI scheme from the URI.
*
* Only the "file" scheme defines the default host "localhost".
* All of `file:/myfile`, `file:///myfile`, and `file://localhost/myfile`
* are equivalent according to RFC 3986. The first format is not accepted
* by PHPs stream functions and thus already normalized implicitly to the
* second format in the Uri class. See `GuzzleHttp\Psr7\Uri::composeComponents`.
*
* Example: file://localhost/myfile → file:///myfile
*/
const REMOVE_DEFAULT_HOST = 8;
/**
* Removes the default port of the given URI scheme from the URI.
*
* Example: http://example.org:80/ → http://example.org/
*/
const REMOVE_DEFAULT_PORT = 16;
/**
* Removes unnecessary dot-segments.
*
* Dot-segments in relative-path references are not removed as it would
* change the semantics of the URI reference.
*
* Example: http://example.org/../a/b/../c/./d.html → http://example.org/a/c/d.html
*/
const REMOVE_DOT_SEGMENTS = 32;
/**
* Paths which include two or more adjacent slashes are converted to one.
*
* Webservers usually ignore duplicate slashes and treat those URIs equivalent.
* But in theory those URIs do not need to be equivalent. So this normalization
* may change the semantics. Encoded slashes (%2F) are not removed.
*
* Example: http://example.org//foo///bar.html → http://example.org/foo/bar.html
*/
const REMOVE_DUPLICATE_SLASHES = 64;
/**
* Sort query parameters with their values in alphabetical order.
*
* However, the order of parameters in a URI may be significant (this is not defined by the standard).
* So this normalization is not safe and may change the semantics of the URI.
*
* Example: ?lang=en&article=fred → ?article=fred&lang=en
*
* Note: The sorting is neither locale nor Unicode aware (the URI query does not get decoded at all) as the
* purpose is to be able to compare URIs in a reproducible way, not to have the params sorted perfectly.
*/
const SORT_QUERY_PARAMETERS = 128;
/**
* Returns a normalized URI.
*
* The scheme and host component are already normalized to lowercase per PSR-7 UriInterface.
* This methods adds additional normalizations that can be configured with the $flags parameter.
*
* PSR-7 UriInterface cannot distinguish between an empty component and a missing component as
* getQuery(), getFragment() etc. always return a string. This means the URIs "/?#" and "/" are
* treated equivalent which is not necessarily true according to RFC 3986. But that difference
* is highly uncommon in reality. So this potential normalization is implied in PSR-7 as well.
*
* @param UriInterface $uri The URI to normalize
* @param int $flags A bitmask of normalizations to apply, see constants
*
* @return UriInterface The normalized URI
*
* @link https://tools.ietf.org/html/rfc3986#section-6.2
*/
public static function normalize(UriInterface $uri, $flags = self::PRESERVING_NORMALIZATIONS)
{
if ($flags & self::CAPITALIZE_PERCENT_ENCODING) {
$uri = self::capitalizePercentEncoding($uri);
}
if ($flags & self::DECODE_UNRESERVED_CHARACTERS) {
$uri = self::decodeUnreservedCharacters($uri);
}
if ($flags & self::CONVERT_EMPTY_PATH && $uri->getPath() === '' &&
($uri->getScheme() === 'http' || $uri->getScheme() === 'https')
) {
$uri = $uri->withPath('/');
}
if ($flags & self::REMOVE_DEFAULT_HOST && $uri->getScheme() === 'file' && $uri->getHost() === 'localhost') {
$uri = $uri->withHost('');
}
if ($flags & self::REMOVE_DEFAULT_PORT && $uri->getPort() !== null && Uri::isDefaultPort($uri)) {
$uri = $uri->withPort(null);
}
if ($flags & self::REMOVE_DOT_SEGMENTS && !Uri::isRelativePathReference($uri)) {
$uri = $uri->withPath(UriResolver::removeDotSegments($uri->getPath()));
}
if ($flags & self::REMOVE_DUPLICATE_SLASHES) {
$uri = $uri->withPath(preg_replace('#//++#', '/', $uri->getPath()));
}
if ($flags & self::SORT_QUERY_PARAMETERS && $uri->getQuery() !== '') {
$queryKeyValues = explode('&', $uri->getQuery());
sort($queryKeyValues);
$uri = $uri->withQuery(implode('&', $queryKeyValues));
}
return $uri;
}
/**
* Whether two URIs can be considered equivalent.
*
* Both URIs are normalized automatically before comparison with the given $normalizations bitmask. The method also
* accepts relative URI references and returns true when they are equivalent. This of course assumes they will be
* resolved against the same base URI. If this is not the case, determination of equivalence or difference of
* relative references does not mean anything.
*
* @param UriInterface $uri1 An URI to compare
* @param UriInterface $uri2 An URI to compare
* @param int $normalizations A bitmask of normalizations to apply, see constants
*
* @return bool
*
* @link https://tools.ietf.org/html/rfc3986#section-6.1
*/
public static function isEquivalent(UriInterface $uri1, UriInterface $uri2, $normalizations = self::PRESERVING_NORMALIZATIONS)
{
return (string) self::normalize($uri1, $normalizations) === (string) self::normalize($uri2, $normalizations);
}
private static function capitalizePercentEncoding(UriInterface $uri)
{
$regex = '/(?:%[A-Fa-f0-9]{2})++/';
$callback = function (array $match) {
return strtoupper($match[0]);
};
return
$uri->withPath(
preg_replace_callback($regex, $callback, $uri->getPath())
)->withQuery(
preg_replace_callback($regex, $callback, $uri->getQuery())
);
}
private static function decodeUnreservedCharacters(UriInterface $uri)
{
$regex = '/%(?:2D|2E|5F|7E|3[0-9]|[46][1-9A-F]|[57][0-9A])/i';
$callback = function (array $match) {
return rawurldecode($match[0]);
};
return
$uri->withPath(
preg_replace_callback($regex, $callback, $uri->getPath())
)->withQuery(
preg_replace_callback($regex, $callback, $uri->getQuery())
);
}
private function __construct()
{
// cannot be instantiated
}
}