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Is Package Here

is_package_here.Rd

Check if required packages are installed locally.

Usage

is_package_here(
  req_package,
  safer_check = TRUE,
  lib_path = NULL,
  error_text = ""
)

Arguments

req_package

Character vector of package names to check.

safer_check

Single logical value. Perform some "safer" checks? If TRUE, checkings are performed before main code running (see the safer-r project): 1) correct lib_path argument value 2) required functions and related packages effectively present in local R libraries and 3) R classical operators (like "<-") not overwritten by another package because of the R scope. Must be set to FALSE if this function is used inside another "safer" function to avoid pointless multiple checkings.

lib_path

Vector of characters specifying the absolute pathways of the directories containing the required packages for the function, if not in the default directories. Useful when R packages are not installed in the default directories because of lack of admin rights. More precisely, lib_path is passed through the new argument of .libPaths() so that the new library paths are unique(c(lib_path, .libPaths())). Warning: .libPaths() is restored to the initial paths, after function execution. Ignored if NULL (default): only the pathways specified by the current .libPaths() are used for package calling.

error_text

Single character string used to add information in error messages returned by the function, notably if the function is inside other functions, which is practical for debugging. Example: error_text = " INSIDE <PACKAGE_1>::<FUNCTION_1> INSIDE <PACKAGE_2>::<FUNCTION_2>.". If NULL, converted into "".

Value

An error message if at least one of the checked packages is missing in lib_path, nothing otherwise.

See also

require.

Author

Gael Millot

Yushi Han

Haiding Wang

Examples

# Warning: these examples may not work well when using the "Run examples" link 
# because of a particular environment. Please, copy-paste in a local environment.
# See also https://safer-r.github.io/saferDev/articles/is_package_here.html
if (FALSE) {
# Example that returns an error
is_package_here(req_package = "nopackage", error_text = " INSIDE P1::F1")
is_package_here(req_package = "ggplot2", lib_path = "C:/Users/gmillot/AppData/Local/R/win-library/4.4") # commented because this example returns an error if the lib_path argument is not an existing directory
}
is_package_here(req_package = "ggplot2")