Check that phantomjs is installed?

[ismayc]

Is there a way to include something like what I have for packages

needed_pkgs <- c("nycflights13", "dplyr", "ggplot2", "knitr", 
  "devtools", "ggplot2", "webshot")
new.pkgs <- needed_pkgs[!(needed_pkgs %in% installed.packages())]

if (length(new.pkgs)) {
  install.packages(new.pkgs, repos = "http://cran.rstudio.com")
}

to check to see if phantomjs is installed? Right now I just have a commented out

#webshot::install_phantomjs()

in the same chunk as my chunk above but it would be nice if I could run a check and install it if needed.

[vnijs]

On a mac you can use Sys.which("phantomjs"). Won't work on Windows though unless phanomjs is in your path

[ismayc]

Thanks! The mac check will work for me for now.

[vnijs]

Just noticed webshot:::find_phantom(). Should work on both Mac and Windows

[ismayc]

Thanks, @vnijs! I completely over-looked that.

[yihui]

Yep, just check if webshot:::find_phantom() is NULL.

[coatless]

Would you folks be interested in a PR with a modified version of install_phantomjs() that checks if it is already installed at the given version? Or an exported package function that detects if phantomjs is present?

[wch]

@coatless Sure, a modified install_phantomjs sounds like a good idea. Maybe with an argument force which defaults to FALSE?

[coatless]

@wch Great! I'll submit a PR to handle this.