dir.create和shinyapps.io的问题

Question

I am trying to get an application running on shinyapps.io. First step is to load a rds file for dropbox access. The the app is supposed to dowload one folder of the dropbox on the server.

I want to create a directory in the "static" directory of the app.

I tried

dir.create (static/...)
dir.create (./static/...)

both works fine locally, but it seems dir.create () does not work on the shinyapps server. https://colomb.shinyapps.io/resultsgallery_software/ https://github.com/smartfigures-dar/SmartFig_Rbased_prototype/tree/dropbox_integration

Note that it seems to work on the 2 first instance and then no more:

local:

for (j in folders$path_display){
print(j)
foldercreated <-dir.create(paste0("./static",j))
}
[1] "/SFB-resultgallery"
[1] "/SFB-resultgallery/Figures"
[1] "/sfb-resultgallery/Figures/atg6-9_KD_in_brain"
[1] "/sfb-resultgallery/Figures/keep_it_short,_no_more_than1"
[1] "/sfb-resultgallery/Figures/2e"
[1] "/sfb-resultgallery/Figures/keep_it_short,_no_more_than"e

shinyapps.io log message:

    2019-07-05T09:42:45.679221+00:00 shinyapps[1012452]: [1] "/SFB-resultgallery"
2019-07-05T09:42:45.679636+00:00 shinyapps[1012452]: [1] "/SFB-resultgallery/Figures"
2019-07-05T09:42:45.679740+00:00 shinyapps[1012452]: [1] "/sfb-resultgallery/Figures/atg6-9_KD_in_brain"
2019-07-05T09:42:45.679936+00:00 shinyapps[1012452]: Warnung in dir.create(paste0("./static", j))
2019-07-05T09:42:45.679938+00:00 shinyapps[1012452]:   kann Verzeichnis './static/sfb-resultgallery/Figures/atg6-9_KD_in_brain' nicht erzeugen. Grund 'No such file or directory'

Answer 1

Short answer: never capitalise folder names.

It took forever to get to the problem and solve it, although the problem is tiny: shinyapps.io and windows deal differently with capital letters: things were saved in "Figures/" and the app tries to access "figures/", no to mention that dropbox messes with it too (file in Figures/ are seen in figures/...)

I wonder if this is somewhere in the doc...

(I am still struggling with the problem hours after finding it ...)