Support more flexible normalizer

[torreytsui]

Many times, I encountered use cases around custom normalization.

NormalizerFormatter::normalize / is_object($data)

To name a few:

• Normalize a custom exception to include extra fields into the context
• Normalize a custom object to include extra fields into the context
• Redact fields from a custom object and selectively normalize non PII information into the context

I understand that we can write our Processor or a Formatter or implement the JsonSerializable to achieve that.

But I can also see that the "nomalization" logic was the main customisation we really needed in those use cases.

The NormalizerFormatter class is great and I don't want to duplicate its logic.

What do you think if we make it more flexible and customizable?

Suggestion 1: introduce protected normalizeObject() method

// Monolog/Formatter/NormalizerFormatter.php

protected function normalize(mixed $data, int $depth = 0): mixed
{
    if (is_object($data)) {
        return $this->normalizeObject($data, $depth);
    }
}

Suggestion 2: introduce normalizer components

// Monolog/Formatter/NormalizerFormatter.php

public function __construct(..., $normalizers);

protected function normalize(mixed $data, int $depth = 0): mixed
{
    // Loop through each normalizer, check its support, and invoke $normalizer->normalise($data, $depth)
}

Or other suggestions? or not really worth it?

[cesarreyes3]

Would this help me if I want to customize the file:line format? https://github.com/Seldaek/monolog/blob/479c936d2c230d8c467bdb3882afab45a6e6b8ad/src/Monolog/Formatter/LineFormatter.php#L261

[Seldaek]

IMO you can already extend and override normalize(), handling any special types you want to handle, then defer to the parent method for the rest. I don't really see what a more complicated system would bring there given this isn't a very common case I think.