Asian characters don't render in PDF reports

Correct, this is a font issue. We only embed Liberation* fonts in the PDF. To display other languages correctly we would need to embed the appropriate fonts based maybe on the request locale or the language setting. I couldn't find a dynamic way to do it while working with Khmer.

We'll have to come up with some kind of strategy for this, even if it is just creating separate language packs for reports with different character sets.

As a temporary workaround I added the following mapping to my app/pdf.py file

# pdf.py
font_map_kr = {'Arial_Normal': 'UnDotum.ttf',
            'Arial_Bold': 'UnDotumBold.ttf',
            'Arial_Italic': 'UnDotum.ttf',
            'Arial_Bold_Italic': 'UnDotumBold.ttf',
            'Times_New_Roman': 'UnBatang.ttf',
            'Times_New_Roman_Bold': 'UnBatangBold.ttf',
            'Times_New_Roman_Italic': 'UnBatang.ttf',
            'Times_New_Roman_Bold_Italic': 'UnBatangBold.ttf'}

font_map = font_map_kr

Then I updated school_tool.conf to point to the unfonts directory:
reportlab_fontdir /usr/share/fonts/truetype/unfonts

I believe these are the Korean fonts installed in Ununtu when you enable Korean language input.

We need a strategy for this. It is ok if it takes the user a few steps -- that's much better than just throwing up our hands.

The font map (see Comment #4) could be moved to schooltool.conf

Also make PDFs use only one font, either serif or sans-serif, not both. Will make it simpler.

OK... is that the plan? Objections?

There's still a minor problem with word-wrap. It needs to be set to CJK when using these fonts. Mixed case (CJK + non-CJK text) is not handled by default in reportlab, IIRC.

Set... where?

2011/11/29 Justas Sadzevičius <email address hidden>:
> There's still a minor problem with word-wrap.  It needs to be set to CJK
> when using these fonts.  Mixed case (CJK + non-CJK text) is not handled
> by default in reportlab, IIRC.
>
> --
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> https://bugs.launchpad.net/bugs/830831
>
> Title:
>  Asian characters don't render in PDF reports
>
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Somewhere in our code. Because of some setting we're yet to implement. Or maybe there's a workaround.

Uninformed opinion follows - I haven't looked at the code at all.

Rather than exporting to PDF where we need to worry a lot about fonts, what about styling the reports with print-specific CSS? It's reasonable to assume that if someone is using the site in an Asian language (or other complex script) that it's already rendering properly in their browser.

It seems like it would be easier for a layman to style the reports and take care of the font-embedding problem.

Yes, that is certainly possible. In general we haven't emphasized the printable web page route because for more formal reports (like ones that are sent home) you really need to be able to do proper page layout, but there is also a place for easier/less formal tabular reports which might be good enough just with print CSS.

Thanks for the suggestion, we'll take a look at weasyprint, especially since it is written in Python. The good thing is we wouldn't need do make an either/or decision. Perhaps we'll start making some new things with it, we wouldn't literally have to ditch ReportLab.

In practice it might be less of a clear win than you'd think, because for formal reports we'd also have to learn a lot about, say, the CSS Paged Media Module, which may end up being as complicated as ReportLab.

But yes, we'll check it out.

Actually, the biggest problem might be the lack of an Ubuntu package, which we'd have to make ourselves.

Could it not be installed as python dependency in schooltool's setup.py ?

As for its usage, you're absolutely right, paging can be a pain, but I find working with CSS - a declarative language designed for layout - more amenable to the manual manipulation of page blocks as in Reportab.

*Python* packaging isn't a problem (eggs, setup.py), but we'd have to have Ubuntu packaging ourselves.

That is, we'd have to do the Ubuntu packaging ourselves.

Status changed to 'Confirmed' because the bug affects multiple users.

This problem also affects Vietnamese. I solved it by following the above workaround and using DejaVu Sans. But upgrading Schooltool erases such modifications. Is there a way that substitute fonts that render correctly in PDF export could be added through the web interface?