URL Documentation¶

The webginition/url package models, normalizes, parses and compares URLs.

The overview provides a high-level introduction to the package classes.

You might want to skip straight to the Url usage guide or the Normalizer usage guide.

Overview¶

Url¶

A Url models a URL, providing component access and modification through the PSR7 UriInterface.

<?php

use webignition\Url\Url;

$url = new Url('http://example.com/path?query#fragment');

$url->getScheme();
// "http"

$url->getQuery();
// "query"

$modifiedUrl = $url
    ->withScheme('https')
    ->withPath('/modified-path')
    ->withQuery('foo=bar')
    ->withFragment('');
(string) $modifiedUrl;
// https://example.com/modified-path?foo=bar

Read the Url usage guide for more detail.

Normalizer¶

The Normalizer can apply any combination of sixteen normalizations to any UriInterface implementation.

<?php

use webignition\Url\Normalizer;

$url = new Url('http://example.com/path?c=cow&a=apple&b=bear#fragment');

$normalizedUrl = Normalizer::normalize(
    $url,
    Normalizer::SORT_QUERY_PARAMETERS | Normalizer::REMOVE_FRAGMENT
);

(string) $normalizedUrl;
// "http://example.com/path?a=apple&b=bear&c=cow"

Flags:

Options:

Read the Normalizer usage guide for more detail.

Parser¶

The Parser transforms a URL string into an array of component parts. Useful for direct access to raw URL components.

The parser is used internally by Url::create() and isn’t needed for normal URL usage.

<?php

use webignition\Url\Parser;

$components = Parser::parse('https://example.com:8080/path?query#fragment');

$components[Parser::COMPONENT_SCHEME];
// "https"

$components[Parser::COMPONENT_HOST];
// "example.com"

Requirements and Installation¶

Requirements¶

PHP 7.2.0 or greater
composer

Installation¶

composer require webignition/url ^3

URL Model¶

A Url models a URL, providing component access and modification through the PSR7 UriInterface.

Minimal non-optional RFC 3986 normalization is applied by default:

converts scheme to lowercase
converts host to lowercase
removes the default port

Creating a URL¶

A new Url instance is created by passing a URL string to the constructor:

<?php

use webignition\Url\Url;

$url = new Url('https://example.com');

Component Access¶

<?php

use webignition\Url\Url;

$url = new Url('https://user:password@example.com:8080/path?query#fragment');

$url->getScheme();
// "https"

$url->getUserInfo();
// "user:password"

$url->getHost();
// "example.com"

$url->getPort();
// 8080

$url->getAuthority();
// "user:password@example.com:8080"

$url->getPath();
// "/path"

$url->getQuery();
// "query"

$url->getFragment();
// "fragment"

Component Modification¶

The Url::with*() are used to set components. A Url is immutable. The return value is a new Url instance.

<?php

use webignition\Url\Url;

$url = new Url('https://user:password@example.com:8080/path?query#fragment');
(string) $url;
// "https://user:password@example.com:8080/path?query#fragment"

$url = $url->withScheme('http');
(string) $modifiedUrl;
// "http://user:password@example.com:8080/path?query#fragment"

$url = $url->withUserInfo('new-user', 'new-password');
(string) $modifiedUrl;
// "http://new-user:new-password@example.com:8080/path?query#fragment"

$url = $url->withUserInfo('');
(string) $modifiedUrl;
// "http://example.com:8080/path?query#fragment"

$url = $url->withHost('new.example.com');
(string) $modifiedUrl;
// "http://new.example.com:8080/path?query#fragment"

$url = $url->withPort(null);
(string) $modifiedUrl;
// "http://new.example.com/path?query#fragment"

$url = $url->withPath('');
(string) $modifiedUrl;
// "http://new.example.com?query#fragment"

$url = $url->withQuery('');
(string) $modifiedUrl;
// "http://new.example.com#fragment"

$url = $url->withFragment('');
(string) $modifiedUrl;
// "http://new.example.com"

Non-Optional Normalization¶

<?php

use webignition\Url\Url;

$url = new Url('HTTPS://EXAMPLE.com:443');

$url->getScheme();
// "https"

$url->getHost();
// "example.com"

$url->getPort();
// null

Normalizer¶

The Normalizer can apply any combination of sixteen normalizations to any UriInterface implementation.

Normalizations are specified through either flags or options. Flags are for normalizations that can be turned or turned off (you either want it or you don’t). Options are for normalizations that act on one or more variables that you get to choose.

Flags:

capitalize percent encoding
decode unreserved characters
convert empty http path
remove default file host
remove port host
remove path dot segments
convert host unicode to punycode
reduce duplicate path slashes
sort query parameters
add path trailing slash-
remove user info
remove fragment
remove www sub-domain

Options:

specify a default scheme
remove filenames from path by pattern
remove query parameters by pattern

Capitalize Percent Encoding¶

Convert percent-encoded triplets (such as %3A) to uppercase. Letters within a percent-encoded triplet are case-insensitive.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com/path%2fvalue');
$normalizedUrl = Normalizer::normalize($url, Normalizer::CAPITALIZE_PERCENT_ENCODING);

(string) $normalizedUrl;
// "http://example.com/path%2Fvalue"

Decode Unreserved Characters¶

Convert percent-encoded characters that have no special meaning to their unencoded equivalents.

Decodes encoded forms of: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com/%75%72%6C');
$normalizedUrl = Normalizer::normalize($url, Normalizer::DECODE_UNRESERVED_CHARACTERS);

(string) $normalizedUrl;
// "http://example.com/url"

Convert Empty HTTP Path¶

Applies a path of / where the path is empty and the scheme is http or https.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com');
$normalizedUrl = Normalizer::normalize($url, Normalizer::CONVERT_EMPTY_HTTP_PATH);

(string) $normalizedUrl;
// "http://example.com/"

Remove Default File Host¶

Removes the host of localhost from a file:// url.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('file://localhost/path');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_DEFAULT_FILE_HOST);

(string) $normalizedUrl;
// "file:///path"

Remove Default Port¶

Removes the port if it matches the default port for the scheme.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com:80');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_DEFAULT_PORT);

(string) $normalizedUrl;
// "http://example.com"

$url = new Url('https://example.com:443');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_DEFAULT_PORT);
(string) $normalizedUrl;
// "https://example.com"

Remove Path Dot Segments¶

The . and .. path segments have a special meaning. These segments are removed and the path is re-written to be equivalent.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com/a/b/c/./../../g');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_PATH_DOT_SEGMENTS);

(string) $normalizedUrl;
// "http://example.com/a/g"

Convert Host Unicode to Punycode¶

Unicode hosts containing non-ascii characters are converted to the punycode equivalent.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://♥.example.com/');
$normalizedUrl = Normalizer::normalize($url, Normalizer::CONVERT_HOST_UNICODE_TO_PUNYCODE);

(string) $normalizedUrl;
// "http://xn--g6h.example.com/"

Reduce Duplicate Path Slashes¶

Reduces occurrences of multiple slashes in the path to single slashes.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com///path//');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REDUCE_DUPLICATE_PATH_SLASHES);

(string) $normalizedUrl;
// "http://example.com/path/"

Sort Query Parameters¶

Alphabetically sorts query parameters by key.

Sorting is neither locale- nor unicode-aware. The purpose is to be able to compare URLs in a reproducible way.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com?c=cow&a=apple&b=bear');
$normalizedUrl = Normalizer::normalize($url, Normalizer::SORT_QUERY_PARAMETERS);

(string) $normalizedUrl;
// "http://example.com?a=apple&b=bear&c=cow"

Add Path Trailing Slash¶

Add a trailing slash to the path if not present.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com');
$normalizedUrl = Normalizer::normalize($url, Normalizer::ADD_PATH_TRAILING_SLASH);

(string) $normalizedUrl;
// "http://example.com/"

Remove User Info¶

Remove user credentials.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://user:password@example.com');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_USER_INFO);

(string) $normalizedUrl;
// "http://example.com"

Remove Fragment¶

Remove fragment component.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com#fragment');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_FRAGMENT);

(string) $normalizedUrl;
// "http://example.com"

Remove www Sub-domain¶

Remove the www sub-domain.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://www.example.com');
$normalizedUrl = Normalizer::normalize($url, Normalizer::REMOVE_WWW);

(string) $normalizedUrl;
// "http://example.com"

Specify a Default Scheme¶

Specify a default scheme to be applied if none is present.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('//www.example.com');
$normalizedUrl = Normalizer::normalize($url, Normalizer::NONE, [
    Normalizer::OPTION_DEFAULT_SCHEME => 'http',
]);

(string) $normalizedUrl;
// "http://example.com"

Remove Filenames From Path By Pattern¶

Remove the filename from the path component. Removal is defined through one or more patterns.

Useful for stripping common default filenames such as index.html, index.js or default.asp.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//www.example.com/index.html');
$normalizedUrl = Normalizer::normalize($url, Normalizer::NONE, [
    Normalizer::OPTION_REMOVE_PATH_FILES_PATTERNS => Normalizer::REMOVE_INDEX_FILE_PATTERN,
]);

(string) $normalizedUrl;
// "http://example.com/"

Remove Query Parameters By Pattern¶

Remove query parameters where the parameter key matches one of a set of patterns.

Useful for stripping query parameters considered by you to be irrelevant to the canonical form of a URL.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//www.example.com?x=1&y=2&utm_source=facebook&utm_medium=18');
$normalizedUrl = Normalizer::normalize($url, Normalizer::NONE, [
    Normalizer::OPTION_REMOVE_QUERY_PARAMETERS_PATTERNS => [
        '/^utm_\w+/i',
    ],
]);

(string) $normalizedUrl;
// "http://example.com?page=1&category=2"

Applying Multiple Normalizations¶

You can apply any number of the sixteen normalizations when normalizing a UriInterface instance.

Multiple Flags¶

Combine flags using the bitwise | operator.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http://example.com?b=bear&a=apple#fragment');
$normalizedUrl = Normalizer::normalize(
    $url,
    Normalizer::SORT_QUERY_PARAMETERS | Normalizer::REMOVE_FRAGMENT
);

(string) $normalizedUrl;
// "http://example.com?a=apple&b=bear"

Options With No Other Normalizations¶

To apply one or more options but no other normalizations, call Normalizer::normalize() with Normalizer::NONE as the flags argument.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//www.example.com?x=1&y=2&utm_source=facebook&utm_medium=18');
$normalizedUrl = Normalizer::normalize($url, Normalizer::NONE, [
    Normalizer::OPTION_REMOVE_QUERY_PARAMETERS_PATTERNS => [
        '/^utm_\w+/i',
    ],
]);

(string) $normalizedUrl;
// "http://example.com?page=1&category=2"

Apply All Semantically-Lossless Normalizations¶

A set of normalizations that do not change the semantics of a URL are defined as Normalizer::PRESERVING_NORMALIZATIONS.

Read more about semantically-lossless normalizations to see what flags this applies.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//♥.example.com:80/p%61th/../?option=%3f');
$normalizedUrl = Normalizer::normalize($url, Normalizer::PRESERVING_NORMALIZATIONS);

(string) $normalizedUrl;
// "http//xn--g6h.example.com:80/path/?option=%3F"

The flags argument of Normalizer::normalize() defaults to Normalizer::PRESERVING_NORMALIZATIONS.

The following is equivalent to the above:

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//♥.example.com:80/p%61th/../?option=%3f');
$normalizedUrl = Normalizer::normalize($url);

(string) $normalizedUrl;
// "http//xn--g6h.example.com:80/path/?option=%3F"

Semantically-Lossless Normalizations¶

There is a set of normalizations that do not change the semantics of a URL. These are defined as Normalizer::PRESERVING_NORMALIZATIONS. The normalizer applies this set of normalizations if no specific normalizations are requested.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//♥.example.com:80/p%61th/../?option=%3f');
$normalizedUrl = Normalizer::normalize($url);

(string) $normalizedUrl;
// "http//xn--g6h.example.com:80/path/?option=%3F"

The Normalizer::PRESERVING_NORMALIZATIONS flag can be used in conjunction with additional normalizations.

<?php

use webignition\Url\Normalizer;
use webignition\Url\Url;

$url = new Url('http//♥.example.com:80/p%61th/../?option=%3f&b=bear&a-apple');
$normalizedUrl = Normalizer::normalize(
    $url,
    Normalizer::PRESERVING_NORMALIZATIONS |
    Normalizer::SORT_QUERY_PARAMETERS
);

(string) $normalizedUrl;
// "http//xn--g6h.example.com:80/path/?a=apple&bear&option=%3F"

Potentially-Lossy Normalizations¶

The reduce path slashes and sort query parameters normalizations are potentially lossy. Semantic equivalence may be commonly achieved but is not guaranteed.

Lossy Normalizations¶

Lossy normalizations change, to a greater or lesser extent, the semantics of a URL.