Read the YAML metadata (and any common _output.yml file) for the
document and return the output format that will be generated by
a call to render.
default_output_format(input, encoding = "UTF-8")Input file (Rmd or plain markdown)
The encoding of the input file; see file
A named list with a name value containing the format
name and an options value that is a list containing all the options
for the format and their values. An option's default value will be returned
if the option isn't set explicitly in the document.
This function is useful for front-end tools that require additional
knowledge of the output to be produced by render (e.g. to
customize the preview experience).