[R] Wrong function when import from module using get

[Jakub Jankiewicz]

By module I mean a package instaled using:

R CMD INSTAL /path/

On Tue, 27 Jun 2017 10:06:16 +0200
Jakub Jankiewicz <jcubic at jcubic.pl> wrote:

> Hi,
> 
> I found this issue:
> 
> when I have 3 modules:
> 
> * AnalysisA
> * AnalysisB
> * AnalysisC
> 
> I load all modules at the beginning from list of modules:
> 
> analyses <- list('AnalysisA', 'AnalysisB', 'AnalysisC')
> 
> for (module in analyses) {
>    library(module, character.only = TRUE)
> }
> 
> and I want to add a function isValid to each module, but I've added it only
> for AnalysisB. When I run this code:
> 
> # value <- <selected by user>
> 
> flags <- sapply(analyses, function(module) {
>     namespace <- getNamespace(module)
>     tryCatch({
>         isValid <- get("isValid", namespace)
>         isValid(value)
>     }, error = function(e) {
>         TRUE
>     })
> })
> 
> # show analyses
> 
> analyses[flags]
> 
> then when R call get for AnalysisA it throw error, for AnalysisB it
> return function but for AnalysisC it return function from AnalysisB and
> don't throw error.
> 
> As a workaround instead of tryCatch I've used:
> 
> if ("isValid" %in% ls(namespace)) {
>     isValid <- get("isValid", namespace)
>     isValid(value)
> } else {
>     TRUE
> }
> 
> Is this a bug? Should this be reported?
> 
> I'm using R 3.4.0 on windows.
> 
> --
> Jakub Jankiewicz, Web Developer
> http://jcubic.pl/me
--
Jakub Jankiewicz, Web Developer
http://jcubic.pl/me