ensureOptionContainer: Ensure Option Container (generic)

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

Description

Ensures the existence of an environment that serves as an option container. The container will be assigned to R option based on signature argument id.

Usage

ensureOptionContainer(id = tryCatch(devtools::as.package(".")$package, error =
  function(cond) {     stop("Invalid default value for `id`") }),
  container = new.env(), sub_id = character(), check = TRUE,
  hidden = TRUE, overwrite = FALSE, ...)

Arguments

id	Signature argument. Object containing suitable information to control the actual ensurance process. In the simplest case, this corresponds to the name/ID of a package/package project. But it can also be an instance of a custom class for which a suitable methods are defined.
container	Signature argument. Object containing container information.
sub_id	character. Optional ID for a sub layer. Useful for a hub-like option container structure.
check	logical. TRUE: check if an R option with name/ID according to the information in id already exists (in which case an error is thrown); FALSE: no check for existing R options. Note that overwrite will overrule check.
hidden	logical. TRUE: make sure name/ID information in id is preprended with a dot to hide it; FALSE: use name/ID information in id as is. The former reduces the risk of accidentially overwriting existing R options and thus is used by default.
overwrite	logical. TRUE: overwrite existing container; FALSE: keep existing container.
...	Further arguments to be passed to subsequent functions/methods.

Author(s)

Janko Thyson [e-mail]

References

http://github.com/Rappster/optionr

See Also

ensureOptionContainer-char-env-method, initializeOptionContainer

Examples

## Not run: 

##------------------------------------------------------------------------------
## Default ID //
##------------------------------------------------------------------------------

options(".optionr" = NULL)
res <- ensureOptionContainer()
".optionr" %in% names(options())
ensureOptionContainer(overwrite = TRUE)
identical(getOption(".optionr"), res)
## --> identical environment object is reused --> ensures pass-by-references
## keeps working even when `overwrite = TRUE`

## Clean up //
options(".optionr" = NULL)

##------------------------------------------------------------------------------
## Explicit ID //
##------------------------------------------------------------------------------

res <- ensureOptionContainer(id = "abcd")
".abcd" %in% names(options())
ensureOptionContainer(id = "abcd", overwrite = TRUE)
identical(getOption(".abcd"), res)
## --> identical environment object is reused --> ensures pass-by-references
## keeps working even when `overwrite = TRUE`

## Clean up //
options(".abcd" = NULL)

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

res <- ensureOptionContainer(id = "abcd", sub_id = "a")
"a" %in% ls(res)

## Clean up //
options(".abcd" = NULL)

##------------------------------------------------------------------------------
## Not hidden //
##------------------------------------------------------------------------------

options("optionr" = NULL)
res <- ensureOptionContainer(hide = FALSE)
"optionr" %in% names(options())
identical(getOption("optionr"), res)

## Clean up //
options("optionr" = NULL)

##------------------------------------------------------------------------------
## Check for existing options of same name/ID //
##------------------------------------------------------------------------------

options(".optionr" = NULL)
res <- ensureOptionContainer()
try(ensureOptionContainer(check = TRUE))

## Clean up //
options(".optionr" = NULL)

##------------------------------------------------------------------------------
## As interface //
##------------------------------------------------------------------------------
  
id <- structure(list(id = "test"), class = "OptionContext.Test")
options("test" = NULL)

res <- ensureOptionContainer(id, hide = FALSE)
"test" %in% names(options())
identical(getOption(id$id), res)  

## Clean up //
options("test" = NULL)


## End(Not run)

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