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Check if user accepted a package installation

check_installed2.Rd

This function returns TRUE if pkg is already installed, and prompt the user to install it otherwise. If the user accepts, returns TRUE, and FALSE if he rejects. This is different from rlang::check_installed() which will exit the function if the user rejects installation.

Useful for suggesting the user a more featureful path of the function, while still allowing a fallback path.

Any installation errors, e.g. packages not found, still bubble up.

Usage

check_installed2(
  pkg,
  reason = NULL,
  ...,
  version = NULL,
  compare = NULL,
  action = NULL,
  call = caller_env()
)

Arguments

pkg

The package names. Can include version requirements, e.g. "pkg (>= 1.0.0)".

reason

Optional string indicating why is pkg needed. Appears in error messages (if non-interactive) and user prompts (if interactive).

...

These dots must be empty.

version

Minimum versions for pkg. If supplied, must be the same length as pkg. NA elements stand for any versions.

compare

A character vector of comparison operators to use for version. If supplied, must be the same length as version. If NULL, >= is used as default for all elements. NA elements in compare are also set to >= by default.

action

An optional function taking pkg and ... arguments. It is called by check_installed() when the user chooses to update outdated packages. The function is passed the missing and outdated packages as a character vector of names.

call

The execution environment of a currently running function, e.g. caller_env(). The function will be mentioned in error messages as the source of the error. See the call argument of abort() for more information.

Value

[TRUE | FALSE] The scalar result of the test.

Examples

# Safely use inside functions without exiting if the package is not installed:
f <- function(x) {
  if (check_installed2("crazy_print_package")) {
    # If the package is installed or the user chooses to install it
    # Some code such as `crazy_print_package::crazy_print(x)`
  } else {
    # If the package is not installed and the user refused to install it
    print(x)
  }
}