API compatibility with asciidoctor-pdf Ruby version

[danyill]

I wanted to recommend this project as a drop-in for the Ruby asciidoctor-pdf for the vscode extension (see this issue asciidoctor/asciidoctor-vscode#239) but found it didn't quite work.

The Ruby version has the following:

 -o, --out-file FILE              output file (default: based on path of input file); use - to output to STDOUT

Whereas the js version has:

  --out-file, -o          output file (default: based on path of input file) use '' to output to STDOUT         [string]

Would you be receptive to using - to enhance compatibility and portability with the Ruby version?

[danyill]

I may be getting this wrong.

I think asciidoctor-pdf Ruby supports the option - being passed by itself (not in connection with -o) for reading from STDIN but currently the js version doesn't support this.

It doesn't seem to be documented for the Ruby version either but is depended on in the asciidoctor-vscode extension (here)

[danyill]

Ah. The documentation is in the user manual: https://asciidoctor.org/docs/user-manual/#piping-content-through-the-cli

[ggrossetie]

It should work both ways, reading from stdin and writing to stdout.

We might need to port this code: https://github.com/asciidoctor/asciidoctor-cli.js/blob/693a9910d4d0a59103b7590ea57dbddf197d4135/lib/invoker.js#L26

[ggrossetie]

Actually there's an issue here:

https://github.com/Mogztter/asciidoctor-pdf.js/blob/3da382ef961dc08ce5f7e86df216251c4407d2c3/lib/converter.js#L101

pdf object is an Uint8Array and toString will return a string representing the specified array and its elements (not the actual data).
We probably need to convert it to a binary string:

function convertUint8ArrayToBinaryString(u8Array) {
  var i, len = u8Array.length, b_str = "";
  for (i=0; i<len; i++) {
    b_str += String.fromCharCode(u8Array[i]);
  }
  return b_str;
}

@danyill To be clear, you want to write the PDF to stdout? or you want to read the AsciiDoc content from stdin? or maybe both?

[danyill]

Well at the moment the vs-code extension only uses stdin to pipe the Asciidoc contents in and then writes to a file. Perhaps it makes sense to have stdout too (I'm not sure).

I've been looking at the way reading from stdin is supported. It seems to require that - is the last argument provided.

See:
https://github.com/asciidoctor/asciidoctor-cli.js/blob/693a9910d4d0a59103b7590ea57dbddf197d4135/lib/options.js#L223-L237

I did a PR with "something like" the changes that are necessary.

[danyill]

Thanks @Mogztter