[R] Query concerning working directory for file.choose()

[J C Nash]

Thanks Duncan. The behaviour is tricky, and I'm still not sure I can predict it. Indeed,
I spent about an hour fiddling with file.choose(). It allows navigation across directories,
so is not totally without value. However, I've noticed users are very prone to making errors
when they aren't in the "right" place, and my application is for non-technical users. In fact,
it is a tool to help people pay bills and get documents online who are new to computing,
or at least to online processing of payments and reports (Canada Post strike in mind!)
and process them in a planned and orderly way so records are safely kept.
(Yes, I realize R is an odd choice, but is IS cross-platform, and the working example uses
YAD in Linux for the dialogs.) I'll welcome discussion of this project offline. Eventually
it should be on Github.

svDialogs seems promising, and I'm now exploring that, though I was disappointed to find
a note (on page 17 of 19 in the pdf manual no less) that "some functions are not working
yet in MacOS". Tests will be needed.

Cheers, John Nash



On 2024-12-18 13:39, Duncan Murdoch wrote:
> I believe file.choose() remembers the last choice, and repeats that location the next time you call it. This is true 
> when it is called at top level or from within a function.
> 
> The first time you call it in a session, it will default to the current working directory, but not after that.
> 
> Front ends are allowed to replace the underlying function, so that may depend on which front end you are using.  I'm 
> talking about R.app on a Mac.
> 
> Duncan Murdoch
> 
> On 2024-12-18 10:32 a.m., J C Nash wrote:
>> I've been working on a small personal project that needs to select files for manipulation from
>> various directories and move them around in planned ways. file.choose() is a nice way to select
>> files. However, I've noticed that if file.choose() is called within a function, it is the
>> directory from which that calling function has been invoked that is displayed by file.choose().
>>
>> This is not altered if I setwd() within that function. Have I misunderstood something or is this
>> an infelicity of file.choose(). sessionInfo() gives my system as
>> R version 4.4.2 (2024-10-31)
>> Platform: x86_64-pc-linux-gnu
>> Running under: Linux Mint 22
>>
>> I've a small example script. It actually helps to create nd1 and nd2 and give them some dummy
>> files before testing.
>>
>> Suggestions welcome.
>>
>> John Nash
>>
>>
>> # fcdir.R -- show directory being used by function that calls file choose
>> cpath<-getwd()
>> nd1<-paste0(cpath,"/nd1")
>> nd2<-paste0(cpath,"/nd2")
>> dir.create(nd1)
>> dir.create(nd2)
>>
>> myfc<-function(){
>>     cat("myfc working in ",getwd(),"\n")
>>     val<-file.choose()
>>     val
>> }
>> myfcd<-function(adir){
>>     setwd(adir)
>>     cat("in myfcd, getwd() =", getwd(),"\n")
>>     val<-file.choose()
>>     val
>> }
>>
>> print(getwd())
>> one<-myfc()
>> cat("one=",one,"\n")
>> setwd("nd1")
>> print(getwd())
>> two<-myfc() # This opens file.choose() in nd1
>> cat("two=",two,"\n")
>> setwd("..")
>> print(getwd())
>> three<-myfcd("nd2") # But this does not
>> cat("three=",three,"\n")
>>
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>