Add option to specify file format to support Shiny fileInput()

[ghost]

When a file is loaded through a fileInput() widget in a Shiny app, it appears that read_excel scans the file name to determine the file type (at least when input$file[,4] - the file path) is used. Shiny uploads an extension-less temporary file so read_excel can't open the file.

[bwbioinfo]

Hi, I ran into this problem as well and my current workaround is as follows:

           file.copy(inFile$datapath,
                      paste(inFile$datapath, ".xlsx", sep=""))
            read_excel(
                    paste(inFile$datapath, ".xlsx", sep=""), 1)

it's not the cleanest but it works.

[andrewcstewart]

thanks for the workaround @Nihasa

[faidherbard]

Hello,
This is not specific to readxl, I ran into the same issue with readr when I wanted to read_csv a zipped CSV file. readr does it right in my R scripts when it has the extension, but it fails with the extension-less temporary file uploaded by Shiny.

[0tertra]

to ensure that the user does upload an .xlsx file, or you need to check the extension you're self to switch between read functions. You can extract the extension as following:

update: instead of file.copy() file.rename() can be used.

ext <- tools::file_ext(inFile$name)
 file.rename(inFile$datapath,
                   paste(inFile$datapath, ext, sep="."))
 read_excel(paste(inFile$datapath, ext, sep="."), 1)

[zross]

I agree that adding the ability to feed read_excel() the extension would be useful, particularly in Shiny where the filename from fileInput drops the extension.