Will recursively flatten messages of a node and all its children.
This helper can for instance be used when errors occurred during a
mapping to flatten all caught errors into a basic array of string that
can then easily be used to inform the user of what is wrong.
```
try {
// …
} catch(MappingError $error) {
$messages = (new MessagesFlattener($error->node()))->errors();
foreach ($messages as $message) {
echo $message;
}
}
```
Can be used to customize the content of messages added during a mapping.
An implementation is provided by the library — `MessageMapFormatter`:
The constructor parameter is an array where each key represents either:
- The code of the message to be replaced
- The content of the message to be replaced
- The class name of the message to be replaced
If none of those is found, the content of the message will stay
unchanged unless a default one is given to this class.
If one of these keys is found, the array entry will be used to replace
the content of the message. This entry can be either a plain text or a
callable that takes the message as a parameter and returns a string; it
is for instance advised to use a callable in cases where a translation
service is used — to avoid useless greedy operations.
In any case, the content can contain placeholders that can be used the
same way as `\CuyZ\Valinor\Mapper\Tree\Message\NodeMessage::format()`.
See usage examples below:
```
$formatter = (new MessageMapFormatter([
// Will match if the given message has this exact code
'some_code' => 'new content / previous code was: %1$s',
// Will match if the given message has this exact content
'Some message content' => 'new content / previous message: %2$s',
// Will match if the given message is an instance of this class
SomeError::class => '
- Original code of the message: %1$s
- Original content of the message: %2$s
- Node type: %3$s
- Node name: %4$s
- Node path: %5$s
',
// A callback can be used to get access to the message instance
OtherError::class => function (NodeMessage $message): string {
if ((string)$message->type() === 'string|int') {
// …
}
return 'Some message content';
},
// For greedy operation, it is advised to use a lazy-callback
'bar' => fn () => $this->translator->translate('foo.bar'),
]))
->defaultsTo('some default message')
// …or…
->defaultsTo(fn () => $this->translator->translate('default'));
$content = $formatter->format($message);
```
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.
