These functions provide a mechanism for (temporarily) using packages outside of the packrat private library. The packages are searched within the 'default' libraries; that is, the libraries that would be available upon launching a new R session.
with_extlib(packages = NULL, expr, envir = parent.frame())
extlib(packages)
user_lib()
packrat_lib()An optional set of package names (as a character
vector) to load for the duration of evaluation of expr.
Whether packages is provided or NULL (the
default), expr is evaluated in an environment where the
external library path is in place, not the local (packrat)
library path.
An R expression.
An environment in which the expression is evaluated.
if (FALSE) { # \dontrun{
with_extlib("lattice", xyplot(1 ~ 1))
with_extlib(expr = packageVersion("lattice"))
# since devtools requires roxygen2 >= 5.0.0 for this step, this
# should fail unless roxygen2 is available in the packrat lib.loc
with_extlib("devtools", load_all("path/to/project"))
# this method will work given roxygen2 is installed in the
# non-packrat lib.loc with devtools
with_extlib(expr = devtools::load_all("path/to/project"))
} # }