PHP RFC: ext/uri follow-up

• Version: 0.1
• Date: 2025-10-17
• Author: Máté Kocsis, kocsismate@php.net
• Status: Draft
• Target version: next minor version (PHP 8.6)
• Implementation: https://github.com/kocsismate/php-src/pull/9

This RFC proposes various follow-up improvements to the URL Parsing API RFC, extending the Uri\Rfc3986\Uri and Uri\WhatWg\Url classes with additional capabilities that came up during the discussion of the original RFC. These capabilities were deemed not to be essential from the get-go, therefore they were postponed in order not to increase scope even further.

The following new functionality is introduced in this proposal:

1. URI Building
2. Query Parameter Manipulation
3. Accessing Path Segments as an Array
4. Host Type Detection
5. URI Type Detection
6. Percent-Encoding and Decoding Support

Each feature proposed is voted separately and requires a 2/3 majority.

Currently, only already existing (and validated) URIs can be manipulated via wither methods. These calls always create a new instance so that immutability of URIs is preserved. Even though this behavior has plenty of advantages, there's at least one disadvantage with this: instance creation has a performance overhead which is not necessary in some cases. This is especially problematic if a lot of URI components have to be modified in the same time, because a lot of objects are “wasted” through intermediate instantiations.

$uri1 = Uri\Rfc3986\Uri::parse("http://example.com");
 
$uri2 = $uri1
    ->withScheme("https")
    ->withHost("example.net")
    ->withPath("/foo/bar");                // This creates 3 objects altogether!

Besides its suboptimal performance, another drawback of the current wither-based solution is that URI creation from the scratch is currently not possible: one always has to have a valid URI first. The empty string is a valid RFC 3986 URI, that's why it may seem a good candidate for an initial URI for URI building, but unfortunately, it's not valid for WHATWG URL. And anyway, the success of some transformations depend on the current state (which is a form of temporal coupling):

$uri1 = Uri\Rfc3986\Uri::parse("");
 
$uri2 = $uri1
    ->withScheme("https")
    ->withUserInfo("user:pass")            // throws Uri\InvalidUriException: Cannot set a userinfo without having a host
    ->withHost("example.com");
 
$uri2 = $uri1
    ->withScheme("https")
    ->withHost("example.com")
    ->withUserInfo("user:pass")            // No exception is thrown

In order to provide a more ergonomic and efficient solution for URI building, a fluent API is introduced that implements the Builder pattern.

$uriBuilder = new Uri\Rfc3986\UriBuilder();
$uriBuilder
    ->setScheme("https")
    ->setUserInfo("user:pass")
    ->setHost("example.com")
    ->setPort(8080)
    ->setPath("/foo/bar")
    ->setQuery("a=1&b=2"])
    ->setQueryParams(["a" => 1, "b" => 2]) // Has the same effect as the setQuery() call above
    ->setFragment("section1")
 
$uri = $uriBuilder->build();               // Validation and instance creation is only done at this point
 
echo $uri->toRawString();                  // https://user:pass@example.com:8080/foo/bar?a=1&b=2#section1

The same works for WHATWG URL:

$urlBuilder = new Uri\WhatWg\UrlBuilder();
$urlBuilder
    ->setScheme("https")
    ->setUserInfo("user:pass")
    ->setHost("example.com")
    ->setPort(8080)
    ->setPath("/foo/bar")
    ->setQuery("a=1&b=2"])
    ->setQueryParams(["a" => 1, "b" => 2]) // Has the same effect as the setQuery() call above
    ->setFragment("section1")
 
$url = $urlBuilder->build();               // Validation and instance creation is only done at this point
 
echo $url->toAsciiString;                  // https://user:pass@example.com:8080/foo/bar?a=1&b=2#section1

The complete class signatures to be added are the following:

namespace Uri\Rfc3986 {
    final class UriBuilder
    {
        public function __construct() {}
 
        public function setScheme(?string $scheme): static {}
 
        public function setUsername(?string $username): static {}
 
        public function setPassword(?string $password): static {}
 
        public function setUserInfo(?string $userInfo): static {}
 
        public function setHost(?string $host): static {}
 
        public function setPath(string $path): static {}
 
        public function setQuery(?string $query): static {}
 
        public function setQueryParams(mixed $queryParams): static {}
 
        public function setFragment(?string $fragment): static {}
 
        public function build(?\Uri\Rfc3986\Uri $baseUrl = null): \Uri\Rfc3986\Uri {}
    }
}

namespace Uri\WhatWg {
    final class UrlBuilder
    {
        public function __construct() {}
 
        public function setScheme(?string $scheme): static {}
 
        public function setUsername(?string $username): static {}
 
        public function setPassword(?string $password): static {}
 
        public function setUserInfo(?string $userInfo): static {}
 
        public function setHost(?string $host): static {}
 
        public function setPath(string $path): static {}
 
        public function setQuery(?string $query): static {}
 
        public function setQueryParams(mixed $queryParams): static {}
 
        public function setFragment(?string $fragment): static {}
 
        /** @param array $errors */
        public function build(?\Uri\WhatWg\Url $baseUrl = null, &$errors = null): \Uri\WhatWg\Url {}
    }
}

Why is a complex Builder pattern based approach is proposed instead of a much simpler Factory Method based one? The factory method could be as simple as the following:

namespace Uri\Rfc3986 {
    final readonly class Uri
    {
        ...
 
        public static function fromComponents(
            ?string $scheme = null, ?string $host = null, string $path = "",
            ?string $userInfo = null, ?string $queryString = null, ?string $fragment = null
        ) {}
 
        ...
    }
}
 
namespace Uri\WhatWg {
    final readonly class Url
    {
        ...
 
        public static function fromComponents(
            string $scheme, ?string $host = "", string $path = "",
            ?string $username = null, ?string $password = null,
            ?string $queryString = null, ?string $fragment = null
        ) {}
 
        ...
    }
}

The current RFC proposes the Builder pattern based approach because of its flexibility: it makes it possible to add more convenience methods in the future. Actually, the setQueryParams() method that expects an array of query params instead of the query string representation is already one.

Query parameter manipulation is an integral part of URI handling. WHATWG URL even dedicates a separate section for the URLSearchParams class that implements advanced query parameter handling. Unfortunately, RFC 3986 doesn't have any such capability, so ultimately, both proposed classes closely follow the design of the WHATWG URL specification.

Therefore, the following classes and methods are proposed for addition:

namespace Uri\Rfc3986 {
    final class UriQueryParams implements Countable, InteratorAggregate
    {
        public static function parse(string $queryString): \Uri\Rfc3986\UriQueryParams {}
 
        public static function fromArray(array $queryParams): \Uri\Rfc3986\UriQueryParams {}
 
        private function __construct() {}
 
        public function append(string $name, mixed $value): void {}
 
        public function delete(string $name): void {}
 
        public function deleteWithValue(string $name, mixed $value): bool {}
 
        public function has(string $name): bool {}
 
        public function hasWithValue(string $name, mixed $value): bool {}
 
        public function getFirst(string $name): mixed {}
 
        public function getLast(string $name): mixed {}
 
        public function getAll(?string $name = null): array {}
 
        public function getCount(): int {}
 
        public function set(string $name, mixed $value): void {}
 
        public function sort(): void {}
 
        public function toString(): string {}
 
        public function __serialize(): array {}
 
        public function __unserialize(array $data): void {}
 
        public function __debugInfo(): array {}
    }

    final readonly class Uri
    {
        ...
 
        public function getRawQueryParams(): ?\Uri\Rfc3986\UriQueryParams {}
 
        public function getQueryParams(): ?\Uri\Rfc3986\UriQueryParams {}
 
        #[\NoDiscard(message: "as Uri\Rfc3986\Uri::withQueryParams() does not modify the object itself")]
        public function withQueryParams(?\Uri\Rfc3986\UriQueryParams $queryParams): static {}
 
        ...
    }
}

namespace Uri\WhatWg {
    final class UrlQueryParams implements Countable, IteratorAggregate
    {
        public static function parse(string $queryString): \Uri\WhatWg\UrlQueryParams {}
 
        public static function fromArray(array $queryParams): \Uri\WhatWg\UrlQueryParams {}
 
        private function __construct() {}
 
        public function append(string $name, mixed $value): void {}
 
        public function delete(string $name): void {}
 
        public function deleteWithValue(string $name, mixed $value): void {}
 
        public function has(string $name): bool {}
 
        public function hasWithValue(string $name, string $value): bool {}
 
        public function getFirst(string $name): mixed {}
 
        public function getLast(string $name): mixed {}
 
        public function getAll(?string $name = null): array {}
 
        public function getCount(): int {}
 
        public function set(string $name, mixed $value): void {}
 
        public function sort(): void {}
 
        public function toString(): string {}
 
        public function __serialize(): array {}
 
        public function __unserialize(array $data): void {}
 
        public function __debugInfo(): array {}
    }

    final readonly class Url
    {
        ...
 
        public function getQueryParams(): ?\Uri\WhatWg\UrlQueryParams {}
 
        #[\NoDiscard(message: "as Uri\WhatWg\Url::withQueryParams() does not modify the object itself")]
        public function withQueryParams(?\Uri\WhatWg\UrlQueryParams $queryParams): static {}
 
        ...
    }
}

Both UriQueryParams and UrlQueryParams support two factory methods for instantiation:

• parse() method: It parses a query string into a list of query parameters.
• fromArray() method: It takes an array of query parameters and directly composes the query parameter list object based on it. It may be counter-intuitive, but a multi-dimension array is expected ([["key1" => "value1"], ["key2" => "value2"]]) instead of a single array of key-value pairs ([“key1” => “value1”, “key2” => “value2”]). This is needed to support repeated query parameter names.

The constructor of both classes is private that even throws upon invocation in order to enforce the usage of the above mentioned factory methods. Some examples for instantiation:

$params = Uri\Rfc3986\UriQueryParams::parse("abc=foo&abc=bar"); // Successful instantiation
$params = Uri\Rfc3986\UriQueryParams::fromArray(
    [
        ["abc" => "foo"],
        ["abc" => "bar"],
    ]
);                                                              // Successful instantiation - same result as above
 
$params = new Uri\Rfc3986\UriQueryParams();                     // Thrown an exception
 
$params = Uri\WhatWg\UrlQueryParams::parse("abc=foo&abc=bar");  // Successful instantiation
$params = Uri\WhatWg\UrlQueryParams::fromArray(
    [
        ["abc" => "foo"],
        ["abc" => "bar"],
    ]
);                                                              // Successful instantiation - same result as above
 
$params = new Uri\WhatWg\UrlQueryParams();                      // Thrown an exception

It is also possible to create a UriQueryParams or UrlQueryParams instance from an Uri\Rfc3986\Uri or an Uri\WhatWg\Url object, respectively:

$uri = new Uri\Rfc3986\Uri("https://example.com/?foo=bar");
 
$params = $uri->getRawQueryParams();       // Creates a Uri\Rfc3986\UriQueryParams instance
$params = $uri->getQueryParams();          // Creates a Uri\Rfc3986\UriQueryParams instance
 
$url = new Uri\WhatWg\Url("https://example.com/?foo=bar");
 
$params = $url->getQueryParams();          // Creates a Uri\Rfc3986\UriQueryParams instance

The difference between Uri\Rfc3986\Uri::getRawQueryParams() and Uri\Rfc3986\Uri::getQueryParams() is that the former one passes the “raw” (non-normalized) query string as an input when instantiating Uri\Rfc3986\Uri\UriQueryParams.

The Uri\Rfc3986\Uri::getRawQueryParams(), Uri\Rfc3986\Uri::getQueryParams(), Uri\WhatWg\Url::getQueryParams() methods return null if the query string is missing (e.g. https://example.com/), and an empty query parameter list is returned if the query string is empty (e.g. https://example.com/?).

$uri = new Uri\Rfc3986\Uri("https://example.com/");
echo $uri->getRawQueryParams();            // null
echo $uri->getQueryParams();               // null
 
$uri = new Uri\Rfc3986\Uri("https://example.com/?");
echo $uri->getRawQueryParams();            // A new Uri\Rfc3986\Uri\UriQueryParams containing zero items
echo $uri->getQueryParams();               // A new Uri\Rfc3986\Uri\UriQueryParams containing zero items

The same example with Uri\WhatWg\UrlQueryParams:

$url = new Uri\WhatWg\Url("https://example.com/");
echo $url->getQueryParams();               // null
 
$url = new Uri\WhatWg\Url("https://example.com/?");
echo $url->getQueryParams();               // A new Uri\WhatWg\Url\UrlQueryParams containing zero items

It's important to note that neither of UriQueryParams and UrlQueryParams validate the query parameters appropriately during construction. This behavior is by design, because the idea of WHATWG URL's URLSearchParams class is that it's tolerant for reading, and UriQueryParams and UrlQueryParams follow the same principle. Validation happens anyway when the serialized query parameters are attempted to be written to a URI (via Uri\Rfc3986\Uri::withQueryParams() and Uri\WhatWg\Url::withQueryParams()).

$uri = new Uri\Rfc3986\Uri("https://example.com/");
 
$params = new Uri\Rfc3986\UriQueryParams("#foo=bar"); // Parses an invalid parameter name "#foo"
 
$uri = $uri->withQueryParams($params);                // Throws Uri\InvalidUri exception

The same example with Uri\WhatWg\UrlQueryParams works a bit differently though due to the automatic percent-encoding behavior of WHATWG URL:

$url = new Uri\WhatWg\Url("https://example.com/");
 
$params = new Uri\WhatWg\UrlQueryParams("#foo=bar"); // Parses an invalid parameter name "#baz"
 
$url = $url->withQueryParams($params);               // Success: the query is automatically percent-encoded to "%23foo=bar"

The factory methods cannot fail in practice: they only have memory-related failure cases which are handled by the PHP engine as a fatal error.

According to the WHATWG URL algorithm, the leading “?” character is removed during parsing. It's not the case for RFC 3986 - the leading “?” becomes part of the first query parameter name.

$params = Uri\Rfc3986\UriQueryParams::parse("?abc=foo");
 
// $params internally contains the ["?abc" => "foo"] key-value pair
 
$params = Uri\WhatWg\UrlQueryParams::parse("?abc=foo");
 
// $params internally contains the ["abc" => "foo"] key-value pair

Another difference between the two classes is how they parse percent-encoded characters. While UriQueryParams don't transform any of the input, UrlQueryParams percent-decodes it automatically as per the WHATWG URL specification:

$params = Uri\Rfc3986\UriQueryParams::parse("foo%5B%5D=b%61r"); // Percent-encoded form of "foo[]=bar"
 
// $params internally contains the ["foo%5B%5D" => "b%61r"] key-value pair
 
$params = Uri\WhatWg\UrlQueryParams::parse("foo%5B%5D=b%61r");  // Percent-encoded form of "foo[]=bar"
 
// $params internally contains the ["foo[]" => "bar"] key-value pair

To find out if a parameter exists, the has() and hasWithValue() methods can be used:

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&baz=qux&baz=baz");
 
echo $params->has("baz");                 // true
echo $params->has("non-existent");        // false
 
echo $params->hasWithValue("foo", "bar"); // true 
echo $params->hasWithValue("foo", "baz"); // false

The has() method returns true if there is at least one parameter in the parameter list with the given name, false otherwise. On the other hand, hasWithValue() returns true if the given name and value both matches at least one parameter, otherwise it returns false.

The number of query parameters can be retrieved by calling the getCount() method:

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&baz=qux&baz=baz");
 
echo $params->getCount();                 // 3

There are also a number of methods that can return a query parameter or an array of query parameters:

• getFirst(): Retrieves the first parameter with the given name. This actually implements the get() method in the WHATWG URL specification.
• getLast(): Retrieves the last parameter with the given name. It's a custom addition to the WHATWG URL specification.
• getAll(): Retrieves either all parameters if the $name parameter is null, or all parameters with the given name if the $name parameter is a string.

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&foo=baz&qux=quux");
 
echo $params->getFirst("foo");            // bar
echo $params->getFirst("non-existent");   // null
 
echo $params->getLast("foo");             // baz
echo $params->getLast("non-existent");    // null
 
echo $params->getAll("foo");              // [["foo", "bar"], ["foo", "baz"]]
echo $params->getAll("non-existent");     // []
 
echo $params->getAll(null);               // [["foo", "bar"], ["foo", "baz"], ["qux", "quux"]]
echo $params->getAll();                   // [["foo", "bar"], ["foo", "baz"], ["qux", "quux"]]

All these methods return the natively stores values without applying any transformations. That is, percent-encoding or decoding neither happens in the input or in the output.

$params = new Uri\Rfc3986\UriQueryParams("foo%5B%5D=b%61e");
 
echo $params->getFirst("foo%5B%5D");     // b%61e
echo $params->getFirst("foo[]");         // null
 
echo $params->getLast("foo%5B%5D");      // b%61e
echo $params->getLast("foo[]");          // null
 
echo $params->getAll("foo%5B%5D");       // [["foo%5B%5D", "ab%63"]]
echo $params->getAll("foo[]");           // []

UriQueryParams and UrlQueryParams have their distinct way of percent-encoding and decoding which is mostly similar to the behavior of RFC 3986 URIs and WHATWG URLs, but it doesn't quite work the same way. This section will discuss the specific details.

UriQueryParams builds upon the uriparser library just like RFC 3986 URIs do. Uriparser has its custom query parameter list implementation that follows RFC 1866 in the absence of any clarification in RFC 3986 about how this component should be processed. According to RFC 1866, space characters are replaced by the plus character (+) during percent-encoding, and the rest of the reserved characters are percent-encoded as normally. Percent-decoding inverts these operations.

This behavior clearly deviates from the percent-encoding rules of the query component of RFC 3986 which allows much more characters to be present without percent-encoding (a few examples: “:”, “@”, “?”, “/”), not to mention the difference in how the space character is handled.

On the other hand, UrlQueryParams relies on the URLSearchParams class specified by WHATG URL, that yet again builds upon the application/x-www-form-urlencoded media type for historic reasons, albeit slightly differently than how RFC 1866 specifies it. As usually, WHATWG URL defines a dedicated percent-encoding set:

The application/x-www-form-urlencoded percent-encode set contains all code points, except the ASCII alphanumeric, U+002A (*), U+002D (-), U+002E (.), and U+005F (_).

Also, a dedicated algorithm for “serialization” is defined (in this context, serialization means recomposition - converting the list to a string): the space code point is percent-encoded as the plus code point (+), and the rest of the code points in the percent-encoding set are encoded how WHATWG URL normally does so.

This behavior deviates from the percent-encoding rules of the query component of WHATWG URL, as the query percent-encode set contains much less characters, and the space code point is handled differently again.

It's also important to compare how the percent encoding rules of UriQueryParams and UrlQueryParams differ: they handle the asterisk (*) and the tilde (~) symbols differently: UriQueryParams percent-encodes the first one, but UrlQueryParams doesn't, however UriQueryParams doesn't percent-encode the latter one, but UrlQueryParams does so.

In order to be consistent with the design of Uri\Rfc3986\Uri and the Uri\WhatWg\Url classes, neither UriQueryParams, nor UrlQueryParams have a __toString() magic method. Instead, they contain a custom toString() method that recomposes the query string from the parameters.

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&foo=baz");
echo $params->toString();                // foo=bar&foo=baz
 
$params = new Uri\WhatWg\UrlQueryParams("foo=bar&foo=baz");
echo $params->toString();                // foo=bar&foo=baz

Both Uri\Rfc3986\UriQueryParams::toString() and Uri\WhatWg\UrlQueryParams::toString() automatically percent-encodes the output according to the rules outlined in the previous section.

$params = new Uri\Rfc3986\UriQueryParams([["foo[]" => "bar baz"]]);
echo $params->toString();                // foo%5B%5D=bar+baz
 
$params = new Uri\WhatWg\UrlQueryParams([["foo[]" => "bar baz"]]);
echo $params->toString();                // foo%5B%5D=bar+baz

Unlike Uri\Rfc3986\Uri, the Uri\Rfc3986\UriQueryParams class doesn't have a toRawString() method because it could be misleading what it exactly does: toRawString() couldn't really provide a “raw” representation of the query string, since automatic percent-encoding must happen any way to make the produced query string valid.

If normalization of the recomposed query string is needed, Uri\Rfc3986\Uri is there for the rescue:

$params = new Uri\Rfc3986\UriQueryParams("foo=b%61r"); // Percent-encoded form of "foo=bar"
 
$uri = new Uri\Rfc3986\Uri("https://example.com");
$uri = $uri->withQueryParams($params);
 
echo $uri->getQuery();                                 // foo=bar

The above example demonstrates that query parameter normalization - which involves percent-decoding of the unnecessarily percent-encoded “a” - can still be achieved no matter that UriQueryParams does not have a dedicated toString() variant. Please keep in mind that the last section of the proposal will introduce another possibility to achieve the same result.

After learning about the details of the percent-encoding and decoding behavior of UriQueryParams and UrlQueryParams, it should be clarified how the new classes can interoperate with the existing Uri\Rfc3986\Uri and Uri\WhatWg\Url?

The short answer is they won't have 100% compatibility. But let's see an example where things can go wrong:

$uri = new Uri\Rfc3986\Uri("https://example.com?foo=a b");
$params = $uri->getQueryParams();
$uri = $uri->withQueryParams($params);
 
echo $uri->getQuery();                     // foo=a+b

The above example illustrates how the different percent-encoding mechanism of Uri\Rfc3986\Uri and Uri\Rfc3986\UriQueryParams affect the results: the original “foo=a b” query component is percent-encoded to “foo=a+b” during the $uri->withQueryParams($params) call. That's why the workflow is not roundtripable. Uri\WhatWg\UrlQueryParams and Uri\WhatWg\Url have the very problem, and it's even encoded in the WHATWG URL specification itself.

The append() method can be used to append a parameter to the end of the list. As normally, the same query parameter can be added multiple times:

$params = new Uri\Rfc3986\UriQueryParams("foo=bar");
$params->append("baz", "qux");
$params->append("baz", "qaz");             // Appends "baz" twice
 
echo $params->toString();                  // foo=bar&baz=qux&baz=qaz

Updating a parameter is possible via the set() method:

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&foo=baz");
$params->set("foo", "baz");                // Overwrites the first item "foo", and removes the second one
$params->set("qux", "qaz");                // Appends a new item "qux"
 
echo $params->toString();                  // foo=bar&baz=qux&baz=qaz

Actually, the set() method has a hybrid behavior: if a parameter is not present in the list, then it adds it just like append() does. Otherwise, it overwrites the first item, and removes the rest of the occurrences.

Removing parameters is possible via either the delete() or the deleteWithValue() method: the former one removes all occurrences of the given parameter name, while the latter one removes all occurrences of a parameter if the given name and value both matches it, as demonstrated below:

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&foo=baz&foo=qux");
$params->deleteWithValue("foo", "baz");    // Deletes the "foo=baz" parameter
$params->delete("foo");                    // Deletes the rest of the occurrences: "foo=bar" and "foo=qux"
$params->delete("non-existent");           // The parameter is not present: nothing happens

The last method that can modify the list is sort(), which sorts the parameters alphabetically:

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&baz=qux&baz=baz");
$params->sort();
 
echo $params->toString();                  // baz=baz&baz=qux&foo=bar

None of these methods do any percent-encoding or decoding. This wasn't a question for RFC 3986 though, but WHATWG URL usually does some kind of automatic post-processing.

$params = new Uri\WhatWg\UrlQueryParams("");
$params->append("foo%5B%5D", "ab%63");     // Percent-encoded form of "foo[]=abc"
$params->set("bar%5B%5D", "de%66");        // Percent-encoded form of "bar[]=def"
 
echo $params->toString();                  // foo%5B%5D=ab%63&bar%5B%5D=de%66

As it can be seen, the percent-encoded octets received from the input remained the same in the output.

What's also important to clarify is how non-string values are mapped? PHP's https://www.php.net/manual/en/function.http-build-query.php and functions can map basically any type to query params, however, the exact behavior is not specified by either RFC 3986 or WHATWG URL: RFC 3986 completely omits any information how query parameters should be build, while WHATWG URL's URLSearchParams only accepts and returns string data.

The position of this RFC is that it's important to follow the road that http_build_query() has already paved because of better developer experience and better interoperability with the existing ecosystem. That's why the following type mapping behavior is proposed when a query parameter is added/updated:

• bool: becomes string “0” (in case of false) or string “1” (in case of true)
• int: becomes a numeric string (123 -> “123”)
• float: becomes a decimal string (3.14 -> “3.14”)
• resource: invalid mapping, throws a TypeError
• array: TBD
• object: TBD

The above conversion rules work for both UriQueryParams and UrlQueryParams. However, Uri\Rfc3986\UriQueryParams can additionally properly handle null values: a null input is mapped to a query component so that only the parameter name is present - the “=” and the parameter value is omitted. On the other hand, Uri\WhatWg\UrlQueryParams converts null values to an empty string. Alternatively, it could omit parameters with null values completely, the same way as http_build_query() does.

$params = new Uri\Rfc3986\UriQueryParams("");
 
$params->append("param_null", null);
$params->append("param_bool", true);
$params->append("param_int", 123);
$params->append("param_float", 3.14);
 
var_dump($params->getFirst("param_null"));  // NULL
var_dump($params->getFirst("param_bool"));  // string(1) "1"
var_dump($params->getFirst("param_int"));   // string(3) "123"
var_dump($params->getFirst("param_float")); // string(4) "3.14"
 
echo $params->toString();                   // param_null&param_bool=1&param_int=123&param_float=3.14

Note how UrlQueryParams works differently with regards to null values:

$params = new Uri\WhatWg\UrlQueryParams("");
 
$params->append("param_null", null);
$params->append("param_bool", true);
$params->append("param_int", 123);
$params->append("param_float", 3.14);
 
var_dump($params->getFirst("param_null"));  // string(0) ""
var_dump($params->getFirst("param_bool"));  // string(1) "1"
var_dump($params->getFirst("param_int"));   // string(3) "123"
var_dump($params->getFirst("param_float")); // string(4) "3.14"
 
echo $params->toString();                   // param_null=&param_bool=1&param_int=123&param_float=3.14

Exact array and object casting rules are still to be decided.

The UriQueryParams and UrlQueryParams classes could implement the IteratorAggregate interface in theory. However, it's not possible to do so due to query components that share the same name, e.g.: param=foo&param=bar&param=baz. In this case, the same key (param) would be repeated 3 times - and it's actually not possible to support with iterators.

Cloning of UriQueryParams and UrlQueryParams is supported.

$params1 = new Uri\Rfc3986\UriQueryParams("foo=bar&foo=baz");
$params2 = clone $params1;
 
echo $params1->toString();               // foo=bar&foo=baz
echo $params2->toString();               // foo=bar&foo=baz

UrlQueryParams works the same way:

$params1 = new Uri\WhatWg\UrlQueryParams("foo=bar&foo=baz");
$params2 = clone $params1;
 
echo $params1->toString();                // foo=bar&foo=baz
echo $params2->toString();                // foo=bar&foo=baz

Both classes are serializable and deserializable. The only implementation gotcha is that the serialized format is slightly unexpected: instead of recomposing the query params into a query string, the individual key-value pairs are serialized as an array. This is necessary because both toString implementations automatically percent-encode the input, so using these algorithms would skew the original data, not to mention the fact that Uri\WhatWg\UrlQueryParams::parse() performs automatic percent-decoding too.

Both classes contain a __debugInfo() method that returns all items in the query parameter list in order to make debugging easier.

$params = new Uri\Rfc3986\UriQueryParams("foo=bar&foo=baz&foo=qux");
var_dump($params);
 
/*
object(Uri\Rfc3986\UriQueryParams)#1 (1) {
  ["params"]=> array(3) {
    [0]=>
    array(1) {
      ["foo"]=>
      string(3) "bar"
    }
    [1]=>
    array(1) {
      ["foo"]=>
      string(3) "baz"
    }
    [2]=>
    array(1) {
      ["foo"]=>
      string(3) "qux"
    }
  }
}
*/
 
$params = new Uri\WhatWg\UrlQueryParams("foo=bar&foo=baz&foo=qux");
var_dump($params);
 
/*
object(Uri\WhatWg\UrlQueryParams)#1 (1) {
  ["params"]=> array(3) {
    [0]=>
    array(1) {
      ["foo"]=>
      string(3) "bar"
    }
    [1]=>
    array(1) {
      ["foo"]=>
      string(3) "baz"
    }
    [2]=>
    array(1) {
      ["foo"]=>
      string(3) "qux"
    }
  }
}
*/

Sometimes, accessing path segments rather than the whole path as string is needed. When this is the case, splitting the path to segments manually after retrieval is both inconvenient and disadvantageous performance-wise, especially considering the fact that Uri\Rfc3986\Uri internally stores the path as a list of segments.

In order to better support the related use-cases, the following methods are proposed to be added:

namespace Uri\Rfc3986 {
    final readonly class Uri
    {
        ...
 
        public function getRawPathSegments(): ?array {}
 
        public function getPathSegments(): ?array {}
 
        #[\NoDiscard(message: "as Uri\Rfc3986\Uri::withPathSegments() does not modify the object itself")]
        public function withPathSegments(array $segments): static {}
 
        ...
    }
}

namespace Uri\WhatWg {
    final readonly class Url
    {
        ...
 
        public function getPathSegments(): array {}
 
        #[\NoDiscard(message: "as Uri\WhatWg\Url::withPathSegments() does not modify the object itself")]
        public function withPathSegments(array $segments): static {}
 
        ...
    }
}

This way, it is possible to write the following code:

$uri = new Uri\WhatWg\Uri("https://example.com/foo/bar/baz");
$segments = $uri->getPathSegments();        // ["foo", "bar", "baz"]
 
$uri = $uri->withPathSegments(["a", "b"]);
echo $uri->getPath();                       // /a/b

The same for WHATWG URL:

$url = new Uri\WhatWg\Url("https://example.com/foo/bar/baz");
$segments = $url->getPathSegments();        // ["foo", "bar", "baz"]
 
$url = $url->withPathSegments(["a", "b"]);
echo $url->getPath();                       // /a/b

The getter methods return null if the path is empty (https://example.com), an empty array when the path consists of a single slash (https://example.com/), and a non-empty array otherwise.

Uri\Rfc3986\Uri::withPathSegments() and Uri\WhatWg\Url::withPathSegments() internally concatenate the input segments separated by a / character, and then trigger Uri\Rfc3986\Uri::withPath() and Uri\WhatWg\Url::withPath(), respectively.

Both the RFC 3986 and WHATWG URL specifications distinguish different types of the host component because each of them have different parsing and formatting rules. Probably the most notable example is the IPv6 host type that requires the IPv6 address to be written between a [ and ] pair.

In order to support returning information about the host type, the following enums and methods are proposed to be added:

namespace Uri\Rfc3986 {
    enum UriHostType
    {
        case IPv4;
        case IPv6;
        case IPvFuture;
        case RegisteredName;
    }
 
    final readonly class Uri
    {
        ...
 
        public function getHostType(): ?\Uri\Rfc3986\UriHostType {}
 
        ...
    }
}

namespace Uri\WhatWg {
    enum UrlHostType
    {
        case IPv4;
        case IPv6;
        case Domain;
        case Opaque;
        case Empty;
    }
 
    final readonly class Url
    {
        ...
 
        public function getHostType(): ?\Uri\WhatWg\UrlHostType {}
 
        ...
    }
}

The new getHostType() methods return the type of the host component for both specifications:

$uri = new Uri("https://192.168.0.1/");
echo $uri->getHostType();                  // UriHostType::IPv4
 
$uri = new Uri("https://[2001:db8::1]/");
echo $uri->getHostType();                  // UriHostType::IPv6
 
$uri = new Uri("https://[v1.1.2.3]/");
echo $uri->getHostType();                  // UriHostType::IPvFuture
 
$uri = new Uri("https://example.com/");
echo $uri->getHostType();                  // UriHostType::RegisteredName

The same for WHATWG URL:

$url = new Uri\WhatWg\Url("https://192.168.0.1/");
echo $url->getHostType();                  // UrlHostType::IPv4
 
$url = new Uri\WhatWg\Url("https://[2001:db8::1]/");
echo $uri->getHostType();                  // UrlHostType::IPv6
 
$url = new Uri\WhatWg\Url("https://example.com/");
echo $url->getHostType();                  // UrlHostType::Domain
 
$url = new Uri\WhatWg\Url("scheme://example.com/");
echo $url->getHostType();                  // UrlHostType::Opaque
 
$url = new Uri\WhatWg\Url("mailto://john.doe@example.com");
echo $url->getHostType();                  // UrlHostType::Empty

RFC 3986 distinguishes different URI “types” based on what they begin with.

• Relative-reference: Starts with a path, and the scheme is therefore omitted. Relative-references can be further grouped into the following types:
  • Absolute-path reference: Starts with a single slash (“/”), e.g.: “/foo”
  • Relative-path reference: Starts without a slash (“/”), e.g.: “foo”
  • Network-path reference: Starts with a double slash (“//”) followed by an authority, e.g.: //host/foo
• URI: Starts with the scheme component, and then continues with either the authority, or the path.

In order to better support granular RFC 3986 URI type detection, the following enums and methods are proposed to be added:

namespace Uri\Rfc3986 {
    enum UriType
    {
        case AbsolutePathReference;
        case RelativePathReference;
        case NetworkPathReference;
        case Uri;
    }
 
    final readonly class Uri
    {
        ...
 
        public function getUriType(): Uri\Rfc3986\UriType {}
 
        ...
    }
}

This way, it becomes easier to detect the URI type:

$uri = new Uri\Rfc3986\Uri("https://example.com");
var_dump($uri->getUriType());                     // Uri\Rfc3986\UriType::Uri
 
$uri = new Uri\Rfc3986\Uri("/foo");
var_dump($uri->getUriType());                     // Uri\Rfc3986\UriType::AbsolutePathReference
 
$uri = new Uri\Rfc3986\Uri("foo");
var_dump($uri->getUriType());                     // Uri\Rfc3986\UriType::RelativePathReference
 
$uri = new Uri\Rfc3986\Uri("//host.com/foo");
var_dump($uri->getUriType());                     // Uri\Rfc3986\UriType::NetworkPathReference

The WHATWG URL specification defines some special schemes (http, https, ftp, file, ws, wss), which have distinct parsing and serialization rules. In order to make checks for special URLs easier to perform, a new Uri\WhatWg\Url::isSpecial() method is added:

namespace Uri\WhatWg {
    final readonly class Url
    {
        ...
 
        public function isSpecial(): bool {}
 
        ...
    }
}

This enables low-level control for applications that need to mirror WHATWG behaviors in parsing or normalization.

$url = new Uri\WhatWg\Url("https://example.com");
var_dump($url->isSpecial());                      // true
 
$url = new Uri\WhatWg\Url("custom:example");
var_dump($url->isSpecial());                      // false

Contrarily to the common belief that's probably further affirmed by the urlencode() and urldecode() functions, percent-encoding and decoding are both a context-sensitive process. Context-sensitivity means that different characters need to be percent-encoded/percent-encoded depending on which URI component is being processed.

It should also be mentioned that in fact, urlencode() and urldecode() should rather be used for the application/x-www-form-urlencoded media type, and rawurlencode() and rawurldecode() more closely implements RFC 3986.

For example, the path component dedicates special meaning for the / character. Therefore, this character doesn't necessarily have to be percent-encoded in the path component. There are some cases though when it makes sense to percent-encode them, as highlighted by the first example within the “Advanced examples” section of the original URI RFC. Unfortunately, rawurlencode() doesn't take the component into account, and replaces the “/” with “%2F” unconditionally.

echo rawurlencode("/foo/bar/baz");                // %2Ffoo%2Fbar%2Fbaz

In order to correctly handle percent-encoding and decoding based on the rules of RFC 3986 and WHATWG URL, the following methods and enums are proposed to be added:

namespace Uri\Rfc3986 {
    enum UriPercentEncodingMode
    {
        case UserInfo;
        case Host;
        case RelativeReferencePath;
        case RelativeReferenceFirstPathSegment;
        case Path;
        case PathSegment;
        case Query;
        case FormQuery;
        case Fragment;
        case AllReservedCharacters;
        case All;
    }
 
    final readonly class Uri
    {
        ...
 
        public static function percentEncode(string $input, \Uri\Rfc3986\UriPercentEncodingMode $mode): string {}
 
        public static function percentDecode(string $input, \Uri\Rfc3986\UriPercentEncodingMode $mode): string {}
 
        ...
    }
}

namespace Uri\WhatWg {
    enum UrlPercentEncodingMode
    {
        case UserInfo;
        case Host;
        case OpaqueHost;
        case Path;
        case PathSegment;
        case OpaquePath;
        case OpaquePathSegment;
        case Query;
        case SpecialQuery;
        case FormQuery;
        case Fragment;
    }
 
    final readonly class Url
    {
        ...
 
        public static function percentEncode(string $input, \Uri\WhatWg\UrlPercentEncodingMode $mode): string {}
 
        public static function percentDecode(string $input, \Uri\WhatWg\UrlPercentEncodingMode $mode): string {}
 
        ...
    }
}

The percentEncode() and percentDecode() methods both require an input string and a PercentEncodingMode enum to be passed. The enums make the context of the encoding/decoding processes fully explicit and clear. The following modes are supported:

• Uri\Rfc3986\UriPercentEncodingMode
  • UserInfo: Besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “:”. Any other characters are percent-encoded.
  • Host: If the input string is a valid IPv4, an IPv6 or an IPvFuture address, no percent-encoding is performed, since these host types do not support the process. Otherwise (for registered names), unreserved characters, percent-encoded octets, as well as sub-delimiters are allowed to be present. Any other characters are percent-encoded.
  • AbsolutePathReferenceFirstSegment: The first segment of absolute-path references cannot start with “//” characters (e.g. //foo), otherwise the path would be confusable with a network-path reference. Therefore, besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “:”, “@”. Any other characters are percent-encoded.
  • RelativePathReferenceFirstSegment: The first segment of relative-path references cannot contain a “:” character (e.g. this:that), otherwise the path would be confusable with a scheme name. Therefore, besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “@”. Any other characters are percent-encoded.
  • RelativeReferencePath:
  • Path: Besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “/”, “:”, “@”. Any other characters are percent-encoded.
  • PathSegment: Besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “:”, “@”. Any other characters are percent-encoded.
  • Query: Besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “:”, “@”, “/”, and “?”. Any other characters are percent-encoded.
  • FormQuery: It is mostly the same as Uri\Rfc3986\UriPercentEncodingMode::Query, but it behaves according to the application/x-www-form-urlencode media type rather than RFC 3986. The only difference between the two is that “ ” is encoded as “+”.
  • Fragment: Besides unreserved characters, percent-encoded octets, as well as sub-delimiters, it also allows the following characters to be present: “:”, “@”, “/”, and “?”. Any other characters are percent-encoded.
  • AllReservedCharacters: All reserved characters are percent-encoded. The rest of the characters are left as-is.
  • AllButUnreservedCharacters: Besides unreserved characters and percent-encoded octets, all other characters are percent-encoded.

For the complete ABNF syntax of each component, consult Appendix A of RFC 3986.

• Uri\WhatWg\UrlPercentEncodingMode
  • UserInfo: Besides the code points percent-encoded by Uri\WhatWg\UrlPercentEncodingMode::Path, the following code points are percent-encoded: U+002F (/), U+003A (:), U+003B (;), U+003D (=), U+0040 (@), U+005B ([) to U+005D (]), inclusive, and U+007C (|).
  • OpaqueHost: Control characters, and all code points greater than ~ are percent-encoded.
  • Path: Besides the code points percent-encoded by Uri\WhatWg\UrlPercentEncodingMode::Query, the following code points are percent-encoded: U+003F (?), U+005E (^), U+0060 (`), U+007B ({), and U+007D (}).
  • PathSegment: Besides the code points percent-encoded by Uri\WhatWg\UrlPercentEncodingMode::Query, the following code points are percent-encoded: U+003F (?), U+005E (^), U+0060 (`), U+007B ({), U+007D (}), and U+002F (/).
  • OpaquePathSegment:
  • Query: Besides Control characters, and all code points greater than ~, the following code points are percent-encoded: U+0020 SPACE, U+0022 (“), U+0023 (#), U+003C (<), and U+003E (>).
  • SpecialQuery: Besides the code points percent-encoded by Uri\WhatWg\UrlPercentEncodingMode::Query, the following code points are percent-encoded: U+0027 (')
  • FormQuery: Besides the code points percent-encoded by Uri\WhatWg\UrlPercentEncodingMode::UserInfo, the following code points are percent-encoded: U+0024 ($) to U+0026 (&), inclusive, U+002B (+), U+002C (,), U+0021 (!), U+0027 (') to U+0029 RIGHT PARENTHESIS, inclusive, and U+007E (~).
  • Fragment: Besides Control characters, and all code points greater than ~, the following code points are percent-encoded: U+0020 SPACE, U+0022 (“), U+003C (<), U+003E (>), and U+0060 (`).

Since neither RFC 3986, nor WHATWG URL support percent-encoded characters inside the scheme component, none of the enums contain a Scheme case. WHATWG URL automatically percent-decodes the host when it's special, so Uri\WhatWg\UrlPercentEncodingMode doesn't contain a Host case.

The percentDecode() methods perform the inverted operation of percentEncode(): it decodes every character that is percent-encoded, but which are otherwise allowed by the current percent-encoding mode.

$uri = new Uri\Rfc3986\Uri("https://example.com#_%40%2F"); // The fragment is the percent-encoded form of "_@/"
 
echo Uri\Rfc3986\Uri::percentDecode(
    $uri->getFragment(),
    Uri\Rfc3986\UriPercentEncodingMode::Fragment
);                                                         // _%40/

The ”/” character is allowed in the fragment, so it's needlessly percent-encoded in the URI - that's why it can be percent-decoded by percentDecode(). On the other hand, “@” is not supported in the context of the fragment, so it's kept in the percent-encoded octet form.

RFC 3986 has a sentence that apparently contradicts with the behavior of Uri\Rfc3986\Uri::percentDecode():

Thus, characters in the reserved set are protected from normalization and are therefore safe to be used by scheme-specific and producer-specific algorithms for delimiting data subcomponents within a URI.

According to this rule, reserved characters - even if they are allowed in the context of a component - should not be percent-decoded during normalization. Even though the Uri\Rfc3986\Uri getters respect this rule, the percentDecode() method intentionally disregards it so that it can serve in use-cases where those getters cannot. Let's see an example:

$uri = new Uri\Rfc3986\Uri("https://example.com/?q=%3A%29"); // The query is the percent-encoded form of ":)"
 
echo $uri->getQuery();                            // %3A%29
 
echo Uri\Rfc3986\Uri::percentDecode(
    $uri->getQuery(),
    Uri\Rfc3986\UriPercentEncodingMode::Query
);                                                // :)

As it can be seen above, the getQuery() getter only normalizes the “%20” percent-encoded octet, and it leaves the two reserved characters - “:” and “)” - as-is, even though “)” is allowed in the context of the query (so it shouldn't be percent-encoded at all). By using percentDecode() one can make the input consumable directly, and scheme-specific or producer-specific algorithms should continue to the getters should they need to do any kind of custom processing.

By using the proposed percent-encoding and decoding capabilities, many use-cases will become possible to implement in a specification-compliant way which was difficult to achieve before.

For example, path segments can be properly percent-encoded when they contain the / character:

$uri = new Uri\Rfc3986\Uri("https://example.com");
$uri = $uri->withPathSegments(
    [
        "foo",
        Uri\Rfc3986\Uri::percentEncode("bar/baz", Uri\Rfc3986\UriPercentEncodingMode::PathSegment)
    ]
);
 
$uri->toRawString();                              // https://example.com/foo/bar%2Fbaz

All the proposed changes are completely backward compatible because the affected classes are all final.

Next minor version (PHP 8.6 most likely)

What effect will the RFC have on IDEs, Language Servers (LSPs), Static Analyzers, Auto-Formatters, Linters and commonly used userland PHP libraries?

Existing extensions can continue to use the existing URI API without any changes. Some of the features are exposed as PHPAPI functions through public headers.

None.

None.

None.

https://github.com/kocsismate/php-src/pull/9

After the RFC is implemented, this section should contain:

1. the version(s) it was merged into
2. a link to the git commit(s)
3. a link to the PHP manual entry for the feature

• Add RFC 3986 and WHATWG URL compliant API

None.