assert_file: Display an error if a valid file or directory path

In ChadGoymer/msgr: Extends Messages, Warnings and Errors by Adding Levels and Log Files

Description

This function calls the error() function to display an error if the variable's values are not valid file or directory paths.

Usage

assert_file(
  x,
  level = 1,
  msg_level = getOption("msgr.level"),
  msg_types = getOption("msgr.types"),
  log_path = getOption("msgr.log_path")
)

assert_dir(
  x,
  level = 1,
  msg_level = getOption("msgr.level"),
  msg_types = getOption("msgr.types"),
  log_path = getOption("msgr.log_path")
)

assert_readable(
  x,
  level = 1,
  msg_level = getOption("msgr.level"),
  msg_types = getOption("msgr.types"),
  log_path = getOption("msgr.log_path")
)

assert_writeable(
  x,
  level = 1,
  msg_level = getOption("msgr.level"),
  msg_types = getOption("msgr.types"),
  log_path = getOption("msgr.log_path")
)

assert_url(
  x,
  level = 1,
  msg_level = getOption("msgr.level"),
  msg_types = getOption("msgr.types"),
  log_path = getOption("msgr.log_path")
)

Arguments

x	(any) The variable to check.
level	(integer, optional) The level of the message, from 1 to 10. Default: 1.
msg_level	(integer, optional) The maximum level of messages to output. Default: set in the option "msgr.level".
msg_types	(character, optional) The type to write or display. Must either NULL or one or more from "INFO", "WARNING" or "ERROR". Default: set in the option "msgr.types".
log_path	(character, optional) The file path to the text log file. If set to "", then no logs are written. Default: set in the option "msgr.log_path".

Details

The following validations can be checked:

• assert_file(): 'x' must be an existing file

• assert_dir(): 'x' must be an existing directory

• assert_readable(): 'x' must be a readable directory or file

• assert_writeable(): 'x' must be a writeable directory or file

• assert_url(): 'x' must be a valid URL

Value

If assertion passes then TRUE is returned. This allows you to make multiple assertions separated by &.

Examples

## Not run: 

# No error
assert_file(system.file("DESCRIPTION", package = "msgr"))
# Error
assert_file("no-such-file.txt")

# No error
assert_dir(R.home())
# Error
assert_dir("no-such-directory")

# No error
assert_readable(R.home())
# Error
assert_readable("no-such-directory")

# No error
assert_writeable(Sys.getenv("HOME"))
# Error
assert_writeable("no-such-directory")

# No error
assert_url("https://www.google.com")
# Error
assert_url("no-such-site")


## End(Not run)

ChadGoymer/msgr documentation built on April 10, 2021, 10:31 a.m.