In some situations the type handled by a constructor is only known at
runtime, in which case the constructor needs to know what class must be
used to instantiate the object.
For instance, an interface may declare a static constructor that is then
implemented by several child classes. One solution would be to register
the constructor for each child class, which leads to a lot of
boilerplate code and would require a new registration each time a new
child is created. Another way is to use the attribute
`\CuyZ\Valinor\Mapper\Object\DynamicConstructor`.
When a constructor uses this attribute, its first parameter must be a
string and will be filled with the name of the actual class that the
mapper needs to build when the constructor is called. Other arguments
may be added and will be mapped normally, depending on the source given
to the mapper.
```php
interface InterfaceWithStaticConstructor
{
public static function from(string $value): self;
}
final class ClassWithInheritedStaticConstructor implements InterfaceWithStaticConstructor
{
private function __construct(private SomeValueObject $value) {}
public static function from(string $value): self
{
return new self(new SomeValueObject($value));
}
}
(new \CuyZ\Valinor\MapperBuilder())
->registerConstructor(
#[\CuyZ\Valinor\Attribute\DynamicConstructor]
function (string $className, string $value): InterfaceWithStaticConstructor {
return $className::from($value);
}
)
->mapper()
->map(ClassWithInheritedStaticConstructor::class, 'foo');
```
It is now possible to register a static method constructor that can be
inherited by a child class. The constructor will then be used correctly
to map the child class.
```php
abstract class ClassWithStaticConstructor
{
public string $value;
final private function __construct(string $value)
{
$this->value = $value;
}
public static function from(string $value): static
{
return new static($value);
}
}
final class ChildClass extends ClassWithStaticConstructor {}
(new MapperBuilder())
// The constructor can be used for every child of the parent class
->registerConstructor(ClassWithStaticConstructor::from(...))
->mapper()
->map(ChildClass::class, 'foo');
```
Using two instances of the same class implementing the `__invoke()`
method in one of the mapper builder methods will now be properly handled
by the library
/!\ This change fixes a security issue.
Userland exception thrown in a constructor will not be automatically
caught by the mapper anymore. This prevents messages with sensible
information from reaching the final user — for instance an SQL exception
showing a part of a query.
To allow exceptions to be considered as safe, the new method
`MapperBuilder::filterExceptions()` must be used, with caution.
```php
final class SomeClass
{
public function __construct(private string $value)
{
\Webmozart\Assert\Assert::startsWith($value, 'foo_');
}
}
try {
(new \CuyZ\Valinor\MapperBuilder())
->filterExceptions(function (Throwable $exception) {
if ($exception instanceof \Webmozart\Assert\InvalidArgumentException) {
return \CuyZ\Valinor\Mapper\Tree\Message\ThrowableMessage::from($exception);
}
// If the exception should not be caught by this library, it
// must be thrown again.
throw $exception;
})
->mapper()
->map(SomeClass::class, 'bar_baz');
} catch (\CuyZ\Valinor\Mapper\MappingError $exception) {
// Should print something similar to:
// > Expected a value to start with "foo_". Got: "bar_baz"
echo $exception->node()->messages()[0];
}
```
The mapper is now more type-sensitive and will fail in the following
situations:
- When a value does not match exactly the awaited scalar type, for
instance a string `"42"` given to a node that awaits an integer.
- When unnecessary array keys are present, for instance mapping an array
`['foo' => …, 'bar' => …, 'baz' => …]` to an object that needs only
`foo` and `bar`.
- When permissive types like `mixed` or `object` are encountered.
These limitations can be bypassed by enabling the flexible mode:
```php
(new \CuyZ\Valinor\MapperBuilder())
->flexible()
->mapper();
->map('array{foo: int, bar: bool}', [
'foo' => '42', // Will be cast from `string` to `int`
'bar' => 'true', // Will be cast from `string` to `bool`
'baz' => '…', // Will be ignored
]);
```
When using this library for a provider application — for instance an API
endpoint that can be called with a JSON payload — it is recommended to
use the strict mode. This ensures that the consumers of the API provide
the exact awaited data structure, and prevents unknown values to be
passed.
When using this library as a consumer of an external source, it can make
sense to enable the flexible mode. This allows for instance to convert
string numeric values to integers or to ignore data that is present in
the source but not needed in the application.
---
All these changes led to a new check that runs on all registered object
constructors. If a collision is found between several constructors that
have the same signature (the same parameter names), an exception will be
thrown.
```php
final class SomeClass
{
public static function constructorA(string $foo, string $bar): self
{
// …
}
public static function constructorB(string $foo, string $bar): self
{
// …
}
}
(new \CuyZ\Valinor\MapperBuilder())
->registerConstructor(
SomeClass::constructorA(...),
SomeClass::constructorB(...),
)
->mapper();
->map(SomeClass::class, [
'foo' => 'foo',
'bar' => 'bar',
]);
// Exception: A collision was detected […]
```
The way messages can be customized has been totally revisited, requiring
several breaking changes. All existing error messages have been
rewritten to better fit the actual meaning of the error.
The content of a message can be changed to fit custom use cases; it can
contain placeholders that will be replaced with useful information.
The placeholders below are always available; even more may be used
depending on the original message.
- `{message_code}` — the code of the message
- `{node_name}` — name of the node to which the message is bound
- `{node_path}` — path of the node to which the message is bound
- `{node_type}` — type of the node to which the message is bound
- `{original_value}` — the source value that was given to the node
- `{original_message}` — the original message before being customized
```php
try {
(new \CuyZ\Valinor\MapperBuilder())
->mapper()
->map(SomeClass::class, [/* … */]);
} catch (\CuyZ\Valinor\Mapper\MappingError $error) {
$messages = new MessagesFlattener($error->node());
foreach ($messages as $message) {
if ($message->code() === 'some_code') {
$message = $message->withBody('new / {original_message}');
}
echo $message;
}
}
```
The messages are formatted using the ICU library, enabling the
placeholders to use advanced syntax to perform proper translations, for
instance currency support.
```php
try {
(new MapperBuilder())->mapper()->map('int<0, 100>', 1337);
} catch (\CuyZ\Valinor\Mapper\MappingError $error) {
$message = $error->node()->messages()[0];
if (is_numeric($message->value())) {
$message = $message->withBody(
'Invalid amount {original_value, number, currency}'
);
}
// Invalid amount: $1,337.00
echo $message->withLocale('en_US');
// Invalid amount: £1,337.00
echo $message->withLocale('en_GB');
// Invalid amount: 1 337,00 €
echo $message->withLocale('fr_FR');
}
```
If the `intl` extension is not installed, a shim will be available to
replace the placeholders, but it won't handle advanced syntax as
described above.
---
The new formatter `TranslationMessageFormatter` can be used to translate
the content of messages.
The library provides a list of all messages that can be returned; this
list can be filled or modified with custom translations.
```php
TranslationMessageFormatter::default()
// Create/override a single entry…
->withTranslation(
'fr',
'some custom message',
'un message personnalisé'
)
// …or several entries.
->withTranslations([
'some custom message' => [
'en' => 'Some custom message',
'fr' => 'Un message personnalisé',
'es' => 'Un mensaje personalizado',
],
'some other message' => [
// …
],
])
->format($message);
```
It is possible to join several formatters into one formatter by using
the `AggregateMessageFormatter`. This instance can then easily be
injected in a service that will handle messages.
The formatters will be called in the same order they are given to the
aggregate.
```php
(new AggregateMessageFormatter(
new LocaleMessageFormatter('fr'),
new MessageMapFormatter([
// …
],
TranslationMessageFormatter::default(),
))->format($message)
```
BREAKING CHANGE: The method `NodeMessage::format` has been removed,
message formatters should be used instead. If needed, the old behaviour
can be retrieved with the formatter `PlaceHolderMessageFormatter`,
although it is strongly advised to use the new placeholders feature.
BREAKING CHANGE: The signature of the method `MessageFormatter::format`
has changed.
Enhances most of the messages for the end users.
Two major changes can be noticed:
1. In most cases no class name will be written in the message; it
prevents users that potentially have no access to the codebase to
get a useless/unclear information.
2. The input values are now properly formatted; for instance a string
value will now be written directly instead of the type `string`;
arrays are also handled with the array shape format, for instance:
`array{foo: 'some string'}`.
It is now mandatory to explicitly register custom constructors —
including named constructors — that can be used by the mapper. The
former automatic registration of named constructor feature doesn't
work anymore.
BREAKING CHANGE: existing code must list all named constructors that
were previously automatically used by the mapper, and registerer them
using the method `MapperBuilder::registerConstructor()`.
The method `MapperBuilder::bind()` has been deprecated, the method above
should be used instead.
```php
final class SomeClass
{
public static function namedConstructor(string $foo): self
{
// …
}
}
(new \CuyZ\Valinor\MapperBuilder())
->registerConstructor(
SomeClass::namedConstructor(...),
// …or for PHP < 8.1:
[SomeClass::class, 'namedConstructor'],
)
->mapper()
->map(SomeClass::class, [
// …
]);
```
An object may have several ways of being created — in such cases it is
common to use so-called named constructors, also known as static factory
methods. If one or more are found, they can be called during the mapping
to create an instance of the object.
What defines a named constructor is a method that:
1. is public
2. is static
3. returns an instance of the object
4. has one or more arguments
```php
final class Color
{
/**
* @param int<0, 255> $red
* @param int<0, 255> $green
* @param int<0, 255> $blue
*/
private function __construct(
public readonly int $red,
public readonly int $green,
public readonly int $blue
) {}
/**
* @param int<0, 255> $red
* @param int<0, 255> $green
* @param int<0, 255> $blue
*/
public static function fromRgb(
int $red,
int $green,
int $blue,
): self {
return new self($red, $green, $blue);
}
/**
* @param non-empty-string $hex
*/
public static function fromHex(string $hex): self
{
if (strlen($hex) !== 6) {
throw new DomainException('Must be 6 characters long');
}
/** @var int<0, 255> $red */
$red = hexdec(substr($hex, 0, 2));
/** @var int<0, 255> $green */
$green = hexdec(substr($hex, 2, 2));
/** @var int<0, 255> $blue */
$blue = hexdec(substr($hex, 4, 2));
return new self($red, $green, $blue);
}
}
```
A new class `NodeMessage` is used to wrap messages added to a node
during the mapping. This class will allow further features by giving
access to useful data related to the bound node.
BREAKING CHANGE: as of now every message is wrapped into a `NodeMessage`
it is therefore not possible to check whether the message is an instance
of `Throwable` — a new method `$message->isError()` is now to be used
for such cases.
