Actual question
How do I avoid Rd file name conflicts when
- a S4 generic and its method(s) are not necessarily all defined in the same package (package containing (some of) the custom method(s) depends on the package containing the generic) and
- using
roxygenize()from package roxygen2 to generate the actual Rd files?
I'm not sure if this is a roxygen2 problem or a common problem when the generic and its method(s) are scattered across packages (which IMHO in general definitely is a realistic use-case scenario if you follow a modular programming style).
What's the recommended way to handle these situations?
Illustration
In package pkga
Suppose in package pkga you defined a generic method foo and that you've provided the respective roxygen code that roxygenize() picks up to generate the Rd file:
#' Test function
#'
#' Test function.
#'
#' @param ... Further arguments.
#' @author Janko Thyson \email{janko.thyson@@rappster.de}
#' @example inst/examples/foo.R
#' @docType methods
#' @rdname foo-methods
#' @export
setGeneric(
name="foo",
signature=c("x"),
def=function(
x,
...
) {
standardGeneric("xFoo")
}
)
When roxygenizing() your package, a file called foo-methods.Rd is created in the man subdirectory that serves as the reference Rd file for all methods that might be created for this generic method. So far so good. If all of the methods for this generic are also part of your package, everything's good. For example, this roxygen code would make sure that documentation is added to foo-methods.Rd for the ANY-method of foo:
#' @param x \code{ANY}.
#' @return \code{TRUE}.
#' @rdname foo-methods
#' @aliases foo,ANY-method
#' @export
setMethod(
f="foo",
signature=signature(x="ANY"),
definition=cmpfun(function(
x,
...
) {
return(TRUE)
}, options=list(suppressAll=TRUE))
)
However, if package pkga provides the generic for foo and you decide in some other package (say pkgb) to add a foo-method for x being of class character, then R CMD check will tell you that there is a name clash with respect to Rd file names and/or aliases (as there already exists a Rd file foo-methods.Rd in pkga):
In package pkgb
#' @param x \code{character}.
#' @return \code{character}.
#' @rdname foo-methods
#' @aliases foo,character-method
#' @export
setMethod(
f="foo",
signature=signature(x="character"),
definition=cmpfun(function(
x,
...
) {
return(x)
}, options=list(suppressAll=TRUE))
)
To be more precise, this is the error that's thrown/written to file 00install.out
Error : Q:/pkgb/man/foo-methods.Rd: Sections \title, and \name must exist and be unique in Rd files
ERROR: installing Rd objects failed for package 'pkgb'
Due dilligence
I tried to change the values for @rdname and @aliases to foo_pkgb* (instead of foo*), but \title and \name still are set to foo when roxygenizing and thus the error remains. Any ideas besides manually editing the Rd files generated by roxygenize()?
EDIT 2012-12-01
In light of starting the bounty, the actual question might get a slightly broader flavor:
How can we implement some sort of an "inter-package" check with respect to Rd files and/or how can we consolidate S4 method help files scattered across packages into one single Rd file in order to present a single source of reference to the end-user?