How to patch an S4 method in an R package?
- by Richie Cotton
If you find a bug in a package, it's usually possible to patch the problem with fixInNamespace, e.g. fixInNamespace("mean.default", "base").
For S4 methods, I'm not sure how to do it though. The method I'm looking at is in the gWidgetstcltk package. You can see the source code with
getMethod(".svalue", c("gTabletcltk", "guiWidgetsToolkittcltk"))
I can't find the methods with fixInNamespace.
fixInNamespace(".svalue", "gWidgetstcltk")
Error in get(subx, envir = ns, inherits = FALSE) :
object '.svalue' not found
I thought setMethod might do the trick, but
setMethod(".svalue", c("gTabletcltk", "guiWidgetsToolkittcltk"),
definition = function (obj, toolkit, index = NULL, drop = NULL, ...)
{
widget = getWidget(obj)
sel <- unlist(strsplit(tclvalue(tcl(widget, "selection")),
" "))
if (length(sel) == 0) {
return(NA)
}
theChildren <- .allChildren(widget)
indices <- sapply(sel, function(i) match(i, theChildren))
inds <- which(visible(obj))[indices]
if (!is.null(index) && index == TRUE) {
return(inds)
}
if (missing(drop) || is.null(drop))
drop = TRUE
chosencol <- tag(obj, "chosencol")
if (drop)
return(obj[inds, chosencol, drop = drop])
else return(obj[inds, ])
},
where = "package:gWidgetstcltk"
)
Error in setMethod(".svalue", c("gTabletcltk", "guiWidgetsToolkittcltk"), :
the environment "gWidgetstcltk" is locked; cannot assign methods for function ".svalue"
Any ideas?
