Prawn VS HexaPDF

Prawn pdf: https://github.com/prawnpdf/prawn

Javascript isn't really my thing, so first I had a go with the Prawn library in ruby, but now I'm hacking LuaTex via Fennel and having a blast.

You have a few options when trying to create a PDF in a Rails environment. Prawn and Wicked PDF have been around for quite a while. I have been using both gems and they work fine. However, they have a few limitations that can make it difficult to handle more complex PDFs. I recently discovered Grover, which can remediate some of this inflexibility in creating PDFs.

On this note, Ruby’s Prawn is great at the writing half and I miss it in pretty much every other language.

I have just released my new gem hexapdf-extras which provides additional functionality on top of the HexaPDF library.

Regarding TrueType font support: What I meant was that the library isn't a full TrueType font library but contains just the parts necessary for PDF supports. So what it can do is write a subset of a TrueType file because that's needed. But it can't serialize any arbitrary TrueType tables and it only handles those TrueType tables needed for displaying text in PDF. More advanced things like glyph positioning based on the language and characters in question is also not supported but may be in the future. Have a look at https://github.com/gettalong/hexapdf/tree/master/lib/hexapdf/font/true_type/ to see the implementation. All the things in this folder and below should be independent of PDF.

TrueType subsetting mainly consists of generating the necessary glyph and various index tables, and copying over all the other necessary tables which don't need to be adjusted. See https://github.com/gettalong/hexapdf/blob/master/lib/hexapdf/font/true_type/subsetter.rb for what is needed to subset.

for all my PDF processing needs, courtesy of HexaPDF,

Break the "rules" if need be. There is no need to separate out small classes into their own file because "something says so". If one were to look for the file of such a class, they would see there isn't one and automatically look into the file of the parent module/class. See e.g. https://github.com/gettalong/hexapdf/blob/master/lib/hexapdf/type/annotation.rb

I'm currently in the process of adding support for digital signatures to HexaPDF.

The code for all this is in the devel branch if you want to try it out.

There are a variety of command line tools like HexaPDF and qpdf that can do this; however, they need to be used on the command line.

After I got some feedback about missing examples in the API documentation of HexaPDF, I decided to do something about it.

If you want to do something like this in Ruby, have a look at HexaPDF - https://hexapdf.gettalong.org/ - which provides a full-blown implementation for reading and writing PDFs and is quite mature already (n.b. I'm the author).

It is licensed AGPL+Commercial but if you just use it for yourself, this does not matter as you can use the AGPL.