Debugging error messages

[kaneplusplus]

Is there a good way to debug error messages that don't show up until interacting with the viewer? I'm getting the following error message only when opening the Table Sort/Filter tab.

Error: argument is of length zero.

The message in the terminal is below.

Error in if (!is.na(curInfo$type)) { : argument is of length zero

I suspect it's a problem with the cognostics I've defined but I'm not positive (the univariate and bivariate filters work fine).

[hafen]

This looks like it's related to an issue I've been meaning to fix for a while. I would guess that in your cognostics function, you did not wrap one or more of your cognostics with cog(). That function simply adds some attributes to your cognostic such as the description, but also infers the cognostics type, which is being checked when this error pops up. This shouldn't be a requirement - it should be done automatically for you if you don't do it, so I need to fix that. But for now, the fix should be to wrap each cognostic with cog(). If you are already doing this and still getting this error then I'll need to dig deeper.

For debugging the viewer, I usually just stick browser statements in the shiny app code, but that isn't a very user-friendly way to do it for others. I'll play around with things like options(error=browser) or options(shiny.error=browser) and see if I can come up with a good recommendation.

[kaneplusplus]

OK, thanks. FYI, my issue was that one of my cognostics was generating NA's on a corner case.

[hafen]

I see. So every value was NA? I'll need to make checking more robust so these things are handled prior to the viewer.

[kaneplusplus]

If you source the following cde and click on the Table Sort/Filter tab the error is reproduced.

library(trelliscope)
iris_small = iris[c(1:2, 51:52, 101:102),]
vdbConn("iris_small_test", name="iris_small_test", autoYes=TRUE)
by_species = divide(iris_small, by="Species", update=TRUE)
makeDisplay(by_species,
            name="iris",
            panelFn=function(x) qplot(Sepal.Length, data=x, geom="histogram"),
            cogFn=function(x) list(num_plants=cog(NA, "Plants")))

[hafen]

Thanks!