A new version of the PHP-Plugin for Coda can be downloaded here:
https://www.chipwreck.de/blog/software/coda-php/.Most important: The previous version had problems when the file was not UTF8-encoded. This version handles such errors better.
At the moment there’s no way in the Coda-API to find out the encoding of the open file. I posted a feature request to the panic guys, but of course I’ve no idea when the Coda Plugin-API will be updated..
And there’s an about box in which the current version of the plugin is shown.