Better error message for the non-support of WOFF fonts

[vpoulailleau]

Thanks for WeasyPrint, I love it!

I lost 1 hour trying to use my @font-face and trying several options (local files, remote files, absolute and relative paths…). I finally discovered that WOFF and WOFF2 fonts are not supported (18010a1) and this is totally OK, I know you're working on removal of cairo and better support.

In the meantime, I think that the following error message:

WARNING: Font-face "Open Sans" cannot be loaded

may be replaced with

WARNING: Font-face "Open Sans" cannot be loaded because WOFF and WOFF2 fonts are not currently supported

I saw an exception here: https://github.com/Kozea/WeasyPrint/blob/master/weasyprint/fonts.py#L357

Maybe it's possible to catch it somewhere and provide a clearer message?

What do you think? (You may answer that I'll just have to wait for the support of WOFF and WOFF2 fonts 😉)

[liZe]

Hello! Thank you for reporting this issue.

You may answer that I'll just have to wait for the support of WOFF and WOFF2 fonts

Right, it’s even already supported in the pydyf branch 😉.

In the meantime, I think that the following error message:

WARNING: Font-face "Open Sans" cannot be loaded

may be replaced with

WARNING: Font-face "Open Sans" cannot be loaded because WOFF and WOFF2 fonts are not currently supported

It’s a bit more complicated than that: this warning is displayed when loading all the different fonts if one @font-face rule have failed. We may have different reasons why loading different fonts fail, we can’t have a specific message here.

But the message of the exception is displayed when you launch WeasyPrint with the --debug option. It’s not useful to display it as a warning, because font-face rules often contain fallback fonts, and one import failing doesn’t mean that the whole font-face rule is failing.

A clean way to do this would be to store the exceptions in a list and display them after the warning message (as warning messages) when they all fail.

Now that WOFF(2) fonts are supported, I’m not sure that it’s really useful to have this feature. Letting developers know that there’s a --debug option is probably a better idea 😄.

[vpoulailleau]

OK, thanks for all this information. The --debug option is exactly what I needed (I read too fast the --help result…), I now get some messages that indicate the lack of support of WOFF fonts.

I'll try the pydyf branch.

@liZe Just to know, when is it planned to use this branch as the new master branch?

[grewn0uille]

Hi @vpoulailleau! Please have a look at #1232 (comment) :)

[vpoulailleau]

Hi @grewn0uille! Thanks for the good news and for WeasyPrint/pydf!