get_article shouldn't raise RuntimeError

[rgaudin]

Currently, ReadArticle.get_article() raises a RuntimeError should the URL be incorrect. I believe we should either:

• Add an .has_article(url) methods that returns a boolean informing about the existence of the article
• Raise a custom, usable Exception like ArticleNotFound or something.

[mgautierfr]

Yes, RuntimeError is a base, generic exception. We could raise a more specific one.
However, with the planned change in the api openzim/libzim#345, this will change. We should wait for the new api to decide what to do.

[rgaudin]

Reading cython doc and this SO answer (and followings), it seems that we'd still have to declare and map the actual exception as the default behavior is to map everything (but a few standard ones) to RuntimeError.

So should we raise a custom (python for now) NotFound(RuntimeError) exception until openzim/libzim#345 gets implemented and we map the actual NotFound?

[mgautierfr]

Indeed, we will need a custom exception handler both with the new api and the current one.

But I'm not sure that we should spend time on this now as it will change in a close future.