pdf-lib VS WeasyPrint

writePdf: used for writing the final completed PDF after receiving the response from the Claude 3 Opus API, this uses the PDF-lib library to manipulate and modify the final file.

I'm facing that same pain point of programmatic PDF filling. I noodled around in the PDF format and learned it's a bit difficult to deal with fonts and formatting. But I think this client-side library works well enough, as a start: https://pdf-lib.js.org/#:~:text=a%20single%20document.-,Fill...

I've also heard of one paid API that I forgot but seemed to work well, and this related service https://www.jotform.com/, and I also considered porting some server-side libraries to WASM. One day I'll collect all the libraries and findings in a blog post.

Are you looking to programmatically fill any PDF form by detecting the fields? Or are you filling one known PDF template?

Thanks! For PDF form filling, I use the APIs that pdf-lib [0] exposes. That includes text fields, checkboxes, radio buttons, dropdowns and options lists. Give it a try and let me know if you find a type of form field that's missing.

[0] https://github.com/Hopding/pdf-lib

I do not know if some plugin exists, but maybe you have to take a look at https://pdf-lib.js.org/

PDFmake or pdf-lib would be the way to go in my opinion.

Sure! You can build your own PDF editor with a combination of PDF.js and PDF-lib

I stand on the shoulders of giants, namely PDF-lib, PDF-js and React-beautiful-DND – everything else is pretty much custom code.

How one can use a library such as PDF-Lib (npm, website) that:

Is there a reason you didn't consider something like Weasyprint?

https://weasyprint.org

I've gone through a number of systems to convert CV's, business cards, and other docs and it hasn't let me down yet.

You don't _have_ to use a browser. I had very good results with Weasyprint [0]. And there's also PrinceXML [1] if you're willing to pay.

[0]: https://weasyprint.org/

Thanks for your answer! I imagined you would be using PrinceXML behind the scenes since that is probably the gold standard in HTML+CSS rendering.

The only open source alternative I know of is WeasyPrint at https://weasyprint.org/. I'm not sure how well it fares against PrinceXML, though.

And thanks for the pointer to Taffy - I didn't know it before!

Flexbox support has been [included][1] since 2018, although my use case was the prototypical one - a single row w/ 3 columns - so YMMV with how it handles more complex layouts.

[1]: https://github.com/Kozea/WeasyPrint/pull/579

Performance is not the strength of WeasyPrint, meaning that heavy HTML files will increase generation time. You should always compress images before attaching them, as they are not compressed by default. Generating a 50-page-long PDF may take up to a minute in extreme cases, although multi-page documents generated on my project take fewer than 2 seconds to generate.

For Python there is Weasyprint: you prepare the invoice as an HTML document, and Weasyprint turns it into a PDF

https://weasyprint.org/

Well yes, but you can implement HTML+CSS. WeasyPrint did from scratch, and independent implementations of HTML+CSS are considerably more numerous than HTML+CSS+JS.

In a recent project I used https://github.com/Kozea/WeasyPrint/ it is written in python, so you will need to use it like so:

You should maybe check out weasyprint. https://weasyprint.org/