Read and Use Several Objects in an .RData fileInput in Shiny - r

Question

I want to access and use several objects from an uploaded .Rdata file by a Shiny App user.
It is possible by a simple call a load() in the global.R to access several objects stored in a .Rdata but I can't figure out how to access and use these when the .Rdata file is uploaded.
A reproducible example that mimics this related question where the .Rdata file contains only one object.
library(shiny)
# Define several objects and store them to disk
x <- rnorm(100)
y <- rnorm(200)
z <- "some text for the title of the plot"
save(x, file = "x.RData")
save(x, y, z, file = "xyz.RData")
rm(x, y, z)
# Define UI
ui <- shinyUI(fluidPage(
titlePanel(".RData File Upload Test"),
mainPanel(
fileInput("file", label = ""),
actionButton(inputId="plot","Plot"),
plotOutput("hist"))
)
)
# Define server logic
server <- shinyServer(function(input, output) {
observeEvent(input$plot,{
if ( is.null(input$file)) return(NULL)
inFile <- isolate({input$file })
file <- inFile$datapath
# load the file into new environment and get it from there
e = new.env()
name <- load(file, envir = e)
data <- e[[name]]
# Plot the data
output$hist <- renderPlot({
hist(data)
})
})
})
# Run the application
shinyApp(ui = ui, server = server)
This works when uploading x.RData but not with xyz.RData that gives the following error message:
Warning: Error in [[: wrong arguments for subsetting an environment
Stack trace (innermost first):
65: observeEventHandler [/Users/.../Desktop/app.R#31]
1: runApp
Ideally, since the three different objects in the .RData will be reused, I am looking for a solution that would create reactive elements x(), y(), z() that could be reused across several renderXXX().

Answer 1

This code works:
library(shiny)
# Define several objects and store them to disk
x <- rnorm(100)
y <- rnorm(200)
z <- "some text for the title of the plot"
save(x, file = "x.RData")
save(x, y, z, file = "xyz.RData")
rm(x, y, z)
# Define UI
ui <- shinyUI(fluidPage(
titlePanel(".RData File Upload Test"),
mainPanel(
fileInput("file", label = ""),
actionButton(inputId="plot","Plot"),
tableOutput("contents"),
plotOutput("hist"))
)
)
# Define server logic
server <- shinyServer(function(input, output) {
observeEvent(input$plot,{
if ( is.null(input$file)) return(NULL)
inFile <- isolate({input$file })
file <- inFile$datapath
load(file, envir = .GlobalEnv)
# Plot the data
output$hist <- renderPlot({
plot(x,y[1:100],main=z)
})
})
})
# Run the application
shinyApp(ui = ui, server = server)
Produces the plot like: