Unfortunately, you can't use it in injected scripts for several reasons.
- Require.JS loads the snippets with script tags and we don't want to add any script tags to every page when our extensions is running.
- Even if it wouldn't be a problem we still can't load scripts from our extension package with script tag.
- Script tags also has it's own browser scope without the special Opera Extension APIs.
Luckily, latest snapshot of Opera 12.50 Next has the new Resource Loader API. It is just one function which returns reference to "File" object of any file in our extension oex package.