As a translator, I shudder when I read articles like this. It is the type of short-sighted attitude that makes our work so hard.
As a rule, you should _never_ put strings of text that are to be localized in code of any kind. Not only does it require the translator to work in the code, taking far longer than necessary to translate simple texts, but it runs the risk of the code getting damaged in this translation processe. While some translators know enough about code to work in it, most don't. The last thing you want is for your translated code to come back and find it doesn't work. Or not find it doesn't work, until you discover your site is malfunctioning.
The best way to work with localization is to have separate files for each language, which may contain variables and definition, but which won't contain any real code. Each translator can then work on their language file, which you just roll back into your database.