When the output format is HTML,
include_url() inserts an iframe in the
output; otherwise it takes a screenshot of the URL and insert the image in
include_app() takes the URL of a Shiny app and adds
?showcase=0 to it (to disable the showcase mode), then passes the URL
include_url(url, height = "400px")
include_app(url, height = "400px")
A character vector of URLs.
A character vector to specify the height of iframes.
An R object with a special class that knitr recognizes internally to generate the iframes or screenshots.