Invisible font on adobe acrobat reader

[vikeen]

WeasyPrint version: 0.42.2

Python version: 3.6.2

Problem: I'm using a custom font-face (otf). The font renders fine in Chrome, but when using Adobe Acrobat Reader there is no text. What is strange to me is that the line height and content space seems to be preserved. This is akin to the css 'visiblity: hidden' style.

Steps to reproduce:

1. Render the font-face (BookSanity)
2. Open in Adobe Acrobat

Example (pdf and css): example.zip

What can I do to help ensure my font / weasyprint are correct?
PDF rendering is crucial to my business. What material/technology should read up on?

[liZe]

Thank you for this bug report.

The fonts seems to be OK for me when the document is open using Evince or Google Chrome, and when converted into other formats using GhostScript and ImageMagick. (I don't have access to Adobe Reader right now.)

Is that what you expect, or is there some extra text missing?

[vikeen]

@liZe, that looks as expected.

[liZe]

@liZe, that looks as expected.

Then, there's probably something wrong with Adobe Reader. Can you tests other PDF readers and/or other versions of Adobe Reader?

What can I do to help ensure my font / weasyprint are correct?
PDF rendering is crucial to my business. What material/technology should read up on?

There are so many PDF readers now (including the ones included in browsers), it's hard to get something working everywhere. The PDF spec is huge, and largely used implementations create implicit rules. Regularly testing various implementations is the only reliable solution I know.

[vikeen]

Then, there's probably something wrong with Adobe Reader. Can you tests other PDF readers and/or other versions of Adobe Reader?

@liZe, I wouldn't expect this from Adobe given that they are the frontrunner of PDF. I'll test some other versions, but should I be logging issues with them or debugging for Adobe Reader specifically?

[liZe]

I wouldn't expect this from Adobe given that they are the frontrunner of PDF. I'll test some other versions, but should I be logging issues with them or debugging for Adobe Reader specifically?

Adobe devs are probably the only ones who can tell if it's a bug in Reader or if it's a bug in WeasyPrint's stack that's silently ignored by other PDF viewers. I don't know if Adobe provides support for Reader. If they don't, you'll have to find a PDF guru (who I'm not at all).

[drukepple]

@vikeen I suspect the issue is the font file itself. I'm not very literate at all on font files and what goes into them (or PDF files for that matter), but suffice it to say that I'm seeing a similar issue with my fonts, except the text does show up in Adobe Reader, just in Helvetica and not in my chosen font. When I downloaded a free font from fontsquirrel.com, it worked just fine...so I have to suspect the file.

However, I uploaded the font into glypherstudio.com and simply exported it back out, and now it works. I also tried it with your BookSanity, too, and it seems to work. I wonder if there was some incorrect metadata or something in the file that you downloaded that Glyphr will correct/add when exporting. I attached the one font I created for you (just did the Regular typeface...if it works you should do the rest of them)
BookSanity-Glyphr.otf.zip

[drukepple]

Quick update: I got my font to work after exporting and trying in the example files I downloaded from @vikeen ... but when I added them to my real project they didn't work. After a bit of experimentation, I realized that I was running weasyprint with -s ./my-print-styles.css, and the fonts were being ignored even though the rest of the styles were honored. When I put a <link rel="stylesheet" href="my-print-styles.css" type="text/css" media="print"> line in the source HTML document, then suddenly my fonts worked. Apparently reexporting them was not necessary in my case...although it did seem to help BookSanity.

@liZe: why should I have to add a <link> tag to get fonts to load, when I'm specifying the exact same CSS via the -s option?

[liZe]

why should I have to add a tag to get fonts to load, when I'm specifying the exact same CSS via the -s option?

There's a bug! @font-face rules in stylesheets added with the -s option don't work, probably because there's a problem with the font_config parameter.

[liZe]

why should I have to add a tag to get fonts to load, when I'm specifying the exact same CSS via the -s option?

It's fixed by 34e2992. @vikeen Does your problem comes from this bug too?

[vikeen]

@liZe, nah. I use a css link in the html

html = render_to_string(theme_template, context)
            doc = weasyprint.HTML(string=html, base_url=self.request.build_absolute_uri())
            doc.render()
            pdf = doc.write_pdf()

[liZe]

@vikeen Is it possible for you to test Cairo 1.15.4 (or higher)?

[liZe]

@vikeen is there anything new about that?