Respect\Stringifier

Converts any PHP value into a string.

Installation

Package is available on Packagist, you can install it using Composer.

composer require respect/stringifier

This library requires PHP >= 8.3.

IMPORTANT: Be careful with version 2.0

If you are using version 2.0, please be aware of security concerns related to information leakage.

1. Class/Interface/Enum Detection: Version 2.0 would automatically detect and format strings that matched internal class, interface, or enum names. This could expose your application's internal architecture.
2. Callable String Detection: Version 2.0 would interpret strings and arrays as callables by default, potentially exposing sensitive data. .

If you're not stringifiying strings coming from and end-user, you're not at risk. However, later versions changed this to a "secure-by-default" approach, assuming that strings may come from untrusted sources.

Usage

Below a quick guide of how to use the library.

Using as a function

echo Respect\Stringifier\stringify($value);

Using as an object

use Respect\Stringifier\HandlerStringifier;

$stringifier = HandlerStringifier::create();

echo $stringifier->stringify($value);

Examples

use function Respect\Stringifier\stringify;

echo stringify('string') . PHP_EOL;
// "string"

echo stringify(implode(PHP_EOL, ['Multi-line', 'string'])) . PHP_EOL;
// "Multi-line\nstring"

echo stringify(1) . PHP_EOL;
// 1

echo stringify(0.5) . PHP_EOL;
// 0.5

echo stringify(true) . PHP_EOL;
// `true`

echo stringify(false) . PHP_EOL;
// `false`

echo stringify(null) . PHP_EOL;
// `null`

echo stringify(INF) . PHP_EOL;
// `INF`

echo stringify(-INF) . PHP_EOL;
// `-INF`

echo stringify(acos(8)) . PHP_EOL;
// `NaN`

echo stringify([1, 2, 3]) . PHP_EOL;
// `[1, 2, 3]`

echo stringify(['foo' => true, 'bar' => 42, 'baz' => ['qux' => INF, 'quux' => null]]) . PHP_EOL;
// `["foo": true, "bar": 42, "baz": ["qux": INF, "quux": null]]`

echo stringify(tmpfile()) . PHP_EOL;
// `resource <stream>`

echo stringify(new WithProperties()) . PHP_EOL;
// `WithProperties { +$publicProperty=true #$protectedProperty=42 -$privateProperty="something" }`

echo stringify(new WithUninitializedProperties()) . PHP_EOL;
// `WithUninitializedProperties { +$uninitializedProperty=*uninitialized* }`

echo stringify(new class { public int $property = 42; }) . PHP_EOL;
// `class { +$property=42 }`

echo stringify(new class extends WithProperties { }) . PHP_EOL;
// `WithProperties@anonymous { +$publicProperty=true #$protectedProperty=42 }`

echo stringify(fn(int $foo): string => '') . PHP_EOL;
// `Closure { fn(int $foo): string }`

echo stringify(new DateTime()) . PHP_EOL;
// `DateTime { 2023-04-21T11:29:03+00:00 }`

echo stringify(new DateTimeImmutable()) . PHP_EOL;
// `DateTimeImmutable { 2023-04-21T11:29:03+00:00 }`

echo stringify(new Fiber('strlen')) . PHP_EOL;
// `Fiber { strlen(string $string): int }`

echo stringify((static fn(int $number) => yield $number)(7)) . PHP_EOL;
// `Generator { current() => 7 }`

echo stringify(new ConcreteIterator()) . PHP_EOL;
// `ConcreteIterator { current() => 1 }`

echo stringify(new ConcreteStringable()) . PHP_EOL;
// `ConcreteStringable { __toString() => "This is the return of __toString()" }`

echo stringify(new ConcreteJsonSerializable()) . PHP_EOL;
// `ConcreteJsonSerializable { jsonSerialize() => {"0":1,"1":2,"2":3,"foo":true} }`

echo stringify(new WithDebugInfo()) . PHP_EOL;
// `WithDebugInfo { __debugInfo() => ["info": "This is the return of __debugInfo()"] }`

echo stringify(new ArrayObject([1, 2, 3])) . PHP_EOL;
// `ArrayObject { getArrayCopy() => [1, 2, 3] }`

echo stringify(new RuntimeException()) . PHP_EOL;
// `RuntimeException { in file.php:119 }`

echo stringify(new InvalidArgumentException('This is the exception message')) . PHP_EOL;
// `InvalidArgumentException { "This is the exception message" in file.php:112 }`

To see more examples of how to use the library check the integration tests.

Custom stringifiers

Stringifier library is extensible, you can create your own stringifiers and handlers. Considering the internal design, it's best to create an implementation of Handler, and then use it to create a HandlerStringifier.

use Respect\Stringifier\DumpStringifier;
use Respect\Stringifier\Handler;
use Respect\Stringifier\Handlers\CompositeHandler;
use Respect\Stringifier\HandlerStringifier;
use Respect\Stringifier\Stringify;

$compositeHandler = CompositeHandler::create();
$compositeHandler->prependStringifier(new class implements Handler {
    public function handle(mixed $raw, int $depth): ?string
    {
        if (is_object($raw) && method_exists($raw, 'toString')) {
            return $raw->toString();
        }

        return null;
    }
});

$stringifier = new HandlerStringifier($compositeHandler, new DumpStringifier());

echo $stringifier->stringify(new class {
    public function toString(): string
    {
        return 'Hello, world!';
    }
});
// Hello, world!

The DumpStringifier is a fallback stringifier that uses print_r-like output. You can replace it with any other.