### Name: validObject
### Title: Test the Validity of an Object
### Aliases: validObject getValidity setValidity
### Keywords: programming classes

### ** Examples

setClass("track",
          representation(x="numeric", y = "numeric"))
t1 <- new("track", x=1:10, y=sort(stats::rnorm(10)))
## A valid "track" object has the same number of x, y values
validTrackObject <- function(object) {
    if(length(object@x) == length(object@y)) TRUE
    else paste("Unequal x,y lengths: ", length(object@x), ", ",
               length(object@y), sep="")
}
## assign the function as the validity method for the class
setValidity("track", validTrackObject)
## t1 should be a valid "track" object
validObject(t1)
## Now we do something bad
t2 <- t1
t2@x <- 1:20
## This should generate an error
## Not run: try(validObject(t2))
## Don't show: 
stopifnot(is(try(validObject(t2)), "try-error"))
## End Don't show

setClass("trackCurve",
         representation("track", smooth = "numeric"))

## all superclass validity methods are used when validObject
## is called from initialize() with arguments, so this fails
## Not run: trynew("trackCurve", t2)
## Don't show: 
stopifnot(is(try(new("trackCurve", t2)), "try-error"))
## End Don't show

setClass("twoTrack", representation(tr1 = "track", tr2 ="track"))

## validity tests are not applied recursively by default,
## so this object is created (invalidly)
tT  <- new("twoTrack", tr2 = t2)

## A stricter test detects the problem
## Not run: try(validObject(tT, complete = TRUE))
## Don't show: 
stopifnot(is(try(validObject(tT, complete = TRUE)), "try-error"))
## End Don't show