existsRegistryValue-character-character-method: Check Existence of Registry Value (char-char)

In rappster/optionr: Management of customized (and nested) project/package options

Description

See generic: existsRegistryValue

Usage

## S4 method for signature 'character,character'
existsRegistryValue(id,
  where = tryCatch(devtools::as.package(".")$package, error = function(cond) {
      stop("Invalid default value for `where`") }), sub_id = character(),
  default = NULL, strict = c(0, 1, 2), ...)

Arguments

id	character.
where	character.
sub_id	character. Optional ID for a sub layer. Useful for a hub-like option container structure.
default	ANY. Value to be returned if option does not exist. See getOption and getNested.
strict	logical. Controls what happens when id points to a non-existing registry object: 0: ignore and return FALSE to signal that the assignment process was not successful or fail_value depending on the value of return_status 1: ignore and with warning and return FALSE 2: ignore and with error
...	Further arguments to be passed to subsequent functions/methods.

Value

ANY. Component value or for invalid argument input and non-existing component the value of default unless strict == 1 in which case a warning is issued or strict == 2 in which case an error is thrown.

Author(s)

Janko Thyson [e-mail]

References

http://github.com/Rappster/optionr

See Also

existsRegistryValue

Examples

## Not run: 

##------------------------------------------------------------------------------
## Basics //
##------------------------------------------------------------------------------

setRegistryValue(id = "test", value = TRUE)
existsRegistryValue(id = "test")

setRegistryValue(id = "a/b/c", value = 10)
existsRegistryValue(id = "a")
existsRegistryValue(id = "a/b")
existsRegistryValue(id = "a/b/c")
existsRegistryValue(id = "a/b/c/d")

existsRegistryValue(id = "c")
existsRegistryValue(id = "c/d/e")
  
##------------------------------------------------------------------------------
## Strictness levels //
##------------------------------------------------------------------------------

## Empty ID //
existsRegistryValue(id = character())
try(existsRegistryValue(id = character(), strict = 1))
try(existsRegistryValue(id = character(), strict = 2))

## Not-existing //  
existsRegistryValue(id = "c/d/e")
try(existsRegistryValue(id = "c/d/e", strict = 1))
try(existsRegistryValue(id = "c/d/e", strict = 2))

##------------------------------------------------------------------------------
## Explicit `where` //
##------------------------------------------------------------------------------

where <- new.env()
setRegistryValue(id = "a/b/c", value = 10, where = where)
existsRegistryValue(id = "a/b/c", where = where)
existsRegistryValue(id = "a/b/c/d", where = where)
existsRegistryValue(id = "c/d/e", where = where)

##------------------------------------------------------------------------------
## Sub ID //
##------------------------------------------------------------------------------

where <- new.env()
setRegistryValue(id = "a/b/c", value = 10, where = where, sub_id = "sub")
existsRegistryValue(id = "a/b/c", where = where, sub_id = "sub")
existsRegistryValue(id = "a/b/c/d", where = where, sub_id = "sub")
existsRegistryValue(id = "c/d/e", where = where, sub_id = "sub")


## End(Not run)

rappster/optionr documentation built on May 26, 2019, 11:23 p.m.