Update ParsedownExtraPlugin.php

[davehold]

Fixed an issue where this caused the prefix "language" to be added twice (with parsedown 1.8 beta 7)

[taufik-nurrohman]

The option was added to automatically append language- prefix to code block class name without dot prefix. The correct fix would be to check whether a class name already prefixed with language- from the initial state. If that’s the case, do not add prefix.

[taufik-nurrohman]

If that’s your preference, (to add language- prefix manually from the markdown source), you can create the same effect without modifying the core this way:

$Parsedown = new ParsedownExtraPlugin;
$Parsedown->blockCodeClassFormat = '%s';

echo $Parsedown->text(file_get_contents('./example.md'));