CODEWITHSUNDEEP
rshiny
Tim Ka
Tim Ka

Reputation: 142

Loading data files with ShinyFiles

I have several data files that my Shiny app is supposed to load. To achieve this, I try to use the ShinyFiles package. From ui.R:

shinyFilesButton('file', 'Load Dataset', 'Please select a dataset', FALSE)

However, I am unsure about what to put in server.R to load the file. I know how to get the file path and all, but where do I put the load() command?

This is what I try now: (from server.R): 

observeEvent(input$file, {
 inFile <- parseFilePaths(roots=roots, input$file)
 load(as.character(inFile$datapath), envir=.GlobalEnv)
})

The files are data files as saved by save.image() and contains some data frames, matrices and lists produced by another R script. In my Shiny app, I want to use the data mainly for graphics, so I need them to get loaded while the app is running.

Upvotes: 3

Views: 5635

Answers (1)

Batanichek
Batanichek

Reputation: 7871

It s hard to understand what means "Shiny seems not to use the contents"

See example ( -- I have object "y" in my data.)

UI

shinyUI(

  fluidPage(    
    shinyFilesButton('file', 'Load Dataset', 'Please select a dataset', FALSE),
    textOutput("txt")

  )
)

Server

shinyServer(function(input, output,session) {
  shinyFileChoose(input,'file', session=session,roots=c(wd='.'))

  observeEvent(input$file, {
    inFile <- parseFilePaths(roots=c(wd='.'), input$file)
    load(as.character(inFile$datapath), envir=.GlobalEnv)
    })

  output$txt=renderPrint({
  input$file
  if(exists("y")) y})

  })

Text changed from data.

for simplisity you can use reactiveValues like

shinyServer(function(input, output,session) {
  shinyFileChoose(input,'file', session=session,roots=c(wd='.'))
  envv=reactiveValues(y=NULL)
  observeEvent(input$file, {
    inFile <- parseFilePaths(roots=c(wd='.'), input$file)
    load(as.character(inFile$datapath))
    envv$y=y
    })

  output$txt=renderPrint({envv$y})

  })

Both variants work but second better if you need different data in sessions.

Upvotes: 7

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