Access to rmakrdown output filename from knit_print

[bhaskarvk]

Is is possible to get access to the output filename from knit_print ?
I tried looking in knitr::opts_*$get(), where * = chunk, hook, current, template and knitt, but it's not available there. Similarly I even tried looking for it from rmarkdown::metadata but no go there too.

I need it for my widgetframe package, for the rstudio/bookdown#271 issue. If I can determine the output filename, and it's libdir (which is normally outputfile_files), then I can write the child widget in that directory, thus making the child widget files part of the parent widget's lib dir.

[bhaskarvk]

As a hack I can do knitr::opts_chunk$get('fig.path'), which returns outputfile_files/figure-html and remove figure-html and use the path, but I would prefer a non-hacky approach if any.

[yihui]

I don't think the information you need is exposed to users: https://github.com/rstudio/rmarkdown/blob/master/R/render.R

I think it is fine to use knitr::opts_chunk$get('fig.path').