Transformer logger use

[m4olivei]

The use of the logger in the Transformer code can be awkward when appenders are used that list in reverse chronological order. Or even just when each call to $log->debug() is stored in the database as a separate record rather then in a flat file. For example, we are using the Instant Articles SDK in a Drupal module here https://github.com/BurdaMagazinOrg/module-fb_instant_articles and the logs come out like this:

http://take.ms/y59qK

Could we instead build up the whole message as a string using newlines, before calling $log->debug with the entire message?

https://github.com/facebook/facebook-instant-articles-sdk-php/blob/master/src/Facebook/InstantArticles/Transformer/Rules/Rule.php#L20,L25

[simonengelhardt]

Thanks for flagging this @m4olivei. We could consider implementing a custom renderer, but I think just concatenating the message with newlines as you suggest is probably a simpler and better approach. We'll look into it.

[everton-rosario]

Im considering to have a better log on the Transformation process.
Like we have today "warnings" stored under the Transformer object, we can have the step-by-step log there, and we can flush it as we finish to process the file.

Something like:

    // processing and transforming code
    $transformer->appendLog($message)

    // after transformation ends
    $logger->debug($transformer->getFormattedLog());

[everton-rosario]

PR #304 for this.