Hacker News Reader

Hacker News

Comment by masterleep | Hacker News Reader

Full thread

masterleep

Please let this be capable of generating PDFs from HTML from the command line.

View on HN

Yes: https://chromedevtools.github.io/debugger-protocol-viewer/to...

Any idea if you can configure the page DPI with this API?

Yes, the emulation domain has APIs for changing that.

https://wkhtmltopdf.org/

You can download the two tools wkhtmltopdf and wkhtmltoimage which use WebKit to generate pdfs/images.

Sadly wkhtmltopdf's version of Webkit is ancient :( No flexbox, no es6, etc...

I think it just means that the site is poorly designed. I think websites should work correctly everywhere where CSS2.1 and ES3 is supported. Otherwise some users won't be able to view those sites.

No paged media makes page formatting much too painful.

I'm the maintainer of wkhtmltopdf, and it's hopelessly out of date. There's still some bugs in the Chrome print-to-PDF support as support was added just a few days ago:

https://bugs.chromium.org/p/chromium/issues/detail?id=603559

Not sure if all the full functionality that wkhtmltopdf can be ported, it had patches to Qt/WebKit to enable that ... probably will need API enhancements in Chrome. Don't have the time right now, but I registered http://crhtmltopdf.org a while ago hoping that I'd get around to it.

The print to pdf command currently only support default print settings. Adding support for customized page size, header and footer, dpi, etc. is in progress.

Please see bug: https://bugs.chromium.org/p/chromium/issues/detail?id=603559 for updates.

Excellent news, thanks!

If you're willing to wait until Electron releases a Chrome 59 -based build, I'll be updating https://github.com/mixu/electroshot which handles screenshots and print-to-PDF along with a bunch of other niceties.

Does it support paged media?

Is there an easy way to do the opposite? e.g. read PDFs as HTML (intended to be read through a remote shell), or text?

You might be able to tweak this pdf.js example to dump out its canvas element after it renders.

https://github.com/mozilla/pdf.js/blob/master/examples/learn...

Extracting text from PDF is not hard, though PDF only contains low-level formatting instructions so the result might not be nice, especially if the original PDF has any non-trivial formatting, like pull quotes, multi-column text, etc. If you don't care about that or the correct "flow" of text, it should be easy enough to just find all the Tj and TJ operators and extract their operands. You might also need to reverse some ligatures though.

Producing nice semantic HTML is much harder, though also easy if you don't mind every word in a separate absolutely positioned div.

Many PDF reader software already contains empirically tuned routines to infer the text flow and generate text files (because the software needs to handle Select All and Copy), but they often produce bad results.

But if you just want to read a PDF on a remote machine over ssh, the easiest solution might be just transferring the file and then opening it locally, or use X forwarding and open the PDF with a graphic reader.

I'm in the same boat. You might want to check these out:

http://coolwanglu.github.io/pdf2htmlEX/

https://github.com/JonathanLink/PDFLayoutTextStripper

http://tabula.technology/

https://docparser.com

Easy, not so much, depending on exactly what you want to get out of it. I did a project with this once https://www.idrsolutions.com/jpdf2html5/. Last I checked, they only supported it as a Java library that could generate rather nice looking and complete HTML pages from PDF documents. The output was great, but it was kinda pricey and difficult to work with.

On the opposite side of the complexity level, I have also used this http://www.pdfsharp.com/PDFsharp/ to extract bits of text from PDFs. It's free, but you only get access to the raw PDF text with formatting codes. It works fine if you just want to grab a short string, but you got your work cut out for you if you want to do anything more sophisticated.

Not sure of your exact use-case, but mPDF does this well.

https://github.com/mpdf/mpdf

Especially it should adhere to CSS3 page break properties.

FWIW, you can do that now, using phantomjs (which is chrome) http://phantomjs.org/screen-capture.html

> FWIW, you can do that now, using phantomjs (which is chrome) http://phantomjs.org/screen-capture.html

It's based on webkit.

Once upon a time, but not anymore.

https://www.chromium.org/blink

PhantomJS is based on webkit (and an outdated version IIRC + a shitty JS interpreter)

specifically it's qtwebkit and an old version of it.

They recently released a beta version based on a newer version of QtWebKit:

https://bitbucket.org/ariya/phantomjs/downloads/

It's a useful tool (and huge thanks to those who built it -- and SlimerJS for that matter) but whenever I've reached for there's always been some issue to resolve, generally relating to the exact version and/or set of APIs supported. Headless mode (with PDF support -- which it looks like the latest version of the Chromium remote protocol does indeed have) built into a mainstream browsers is nearly guaranteed to be a smoother experience.

Also with https://wkhtmltopdf.org/ and http://pandoc.org/

Tried all of these and haven't found any as good as http://www.nightmarejs.org/

Thats just phantomJS though..

It switched to Electron under the hood a while back.

And, if you need much higher fidelity and control of HTML/CSS -> PDF, there's the fantastic Prince library, http://princexml.com/ (nonfree)

(I've been using Prince for over a decade, rendering everything from prescription labels, packing slips, receipts, resumes, books, and more. It's great.)

That's also an API service, http://docraptor.com, with a different pricing model that uses the Prince library for PDF rendering.

Tough crowd.

Reply on news.ycombinator.com