R Shiny: Attempt to use zero-length variable name

Question

This question has been asked a number of times, but my issue appears to be different.

I'm getting the error message "attempt to use non-zero variable name" whenever I click "Run Document" in R studio for a Shiny .Rmd file. This happens even when I attempt to run the default Shiny template in R studio. It also occurs if I comment out all code blocks except the shiny header (see image).

Knitting a .rmd without Shiny works fine. The same code was working fine last week. I've reinstalled the Shiny and Rmarkdown packages, to no effect.

Any help would be greatly appreciated.

> sessionInfo(NULL) R version 4.0.0 (2020-04-24) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows 10 x64 (build 18362) Matrix products: default locale: [1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base loaded via a namespace (and not attached): [1] compiler_4.0.0 tools_4.0.0 packrat_0.5.0 — Zhaochen He, Jul 15 '20 at 20:58

score 0 · Answer 1 · answered Jul 15 '20 at 21:14

0

I ran into this issue and created a brand new shiny shiny file, which worked. Not sure what the issue was.

answered Jul 15 '20 at 21:14

Mitchell Graham

145
9

I tried that; didn't work. However, I just discovered that if I move the file to a new directory, it works. However, I can't for the life of me get it to work in the old directory. I deleted the old .Rproj file and Rproj.user directory, but still no go. – Zhaochen He Jul 15 '20 at 21:24

score 0 · Answer 2 · answered Jul 16 '20 at 14:46

I believe this has to do with the line error in source(global_r, local =FALSE), which is why moving it to another directory worked. Looks like some option is in this directory that is not set in the other directory. I assume you tried restarting your R session? The source is trying to read in a file or connection I believe that is not available.

this answer says to run this code to redefine your source, tbh not sure if this will help you, but thought it'd be worth a try. looks like alot, but just requires a copy/paste.

source = function (file, local = FALSE, print.eval = echo,
                   verbose = getOption("verbose"),
                   prompt.echo = getOption("prompt"), max.deparse.length = 150,
                   chdir = FALSE, encoding = getOption("encoding"),
                   continue.echo = getOption("continue"), skip.echo = 0,
                   keep.source = getOption("keep.source")) {
base::source(file, local, echo = FALSE, print.eval, verbose, prompt.echo,
               max.deparse.length, chdir, encoding, continue.echo, skip.echo,
               keep.source)
}

R Shiny: Attempt to use zero-length variable name

2 Answers2