In LUMC/rcourse: R Open Online Course (ROOC)

root_dir <- knitr::opts_knit$get("output.dir")
site_dir <- file.path(root_dir,"_site")
exer_dir <- file.path(site_dir,"exercises")
fname <- paste0(params$basename,".tasks.Rmd")
i <- file.path(root_dir,fname)
o <- sub(".Rmd$",".nocode.html",basename(file.path(site_dir,fname)))

rmarkdown::render(input = i ,
                    output_file = o,
                    output_dir = root_dir,
                    output_format = "html_document",
                    quiet = TRUE, params = list(title="aap"))