This should clear up the issue identified by @crism in #20. Two things that I am pretty sure should be true:
There is no need to require any files if vanilla/htmlawed is being used, as in that case it will have been autoloaded with Pressbooks Core.
We should be able to handle backwards compatibility with function_exists(). But this may not even be necessary, as I don't think this version of Pressbooks mPDF will work with Pressbooks < 3.9.8.
Actually: you shouldn't even need to do the backwards-compatibility check, because the mPDF export module was in Pressbooks core prior to 3.9.8. Sorry for the confusion.
This should clear up the issue identified by @crism in #20. Two things that I am pretty sure should be true:
vanilla/htmlawed
is being used, as in that case it will have been autoloaded with Pressbooks Core.function_exists()
. But this may not even be necessary, as I don't think this version of Pressbooks mPDF will work with Pressbooks < 3.9.8.