Dear people of sackoverflow,
I am currently trying to create an app where a user can upload a dataset from various sources. I tried to isolate the code for the upload in a separate Shiny module. However, R throws an error saying that an environment object is not subsettable. I am fairly new to shiny so would appreciate any advice regarding the use of modules too. :)
library(shiny)
fileInputUI <- function(id){
ns <- NS(id)
fileInput(
inputId = ns("file"),
label = "Select a file"
)
}
fileInputServer <- function(id){
moduleServer(id, function(input, output, session){
dataset <- reactive({
req(input$file)
# Get file extension and datapath
ext <- tools::file_ext(input$file$name)
datapath <- input$file$datapath
# Need reactive values to store input data in
read_data_options <- reactiveValues()
read_data_options$sep <- NULL
if(ext == "csv"){
choices_sep <- c(",", ";", "", "\\t")
names(choices_sep) <- c("Comma (,)", "Semicolon (;)", "White space ( )", "Tab separated (\\t)")
showModal(
ui = modalDialog(
selectInput(
inputId = NS(id, "sep"),
label = "Which separator is used for your data",
choices = names(choices_sep),
selected = ""
),
# Input is required so no dismiss button
footer = tagList(
modalButton("Dismiss"),
actionButton(
inputId = NS(id, "submit_csv"),
label = "Submit")
),
easyClose = TRUE
)
)
# Set input value from submit button
observeEvent(
eventExpr = input$submit_csv,
handlerExpr = {
read_data_options$sep <- choices_sep[input$sep]
removeModal()
read.csv(
file = datapath,
sep = read_data_options$sep
)
}
)
} else {
NULL
}
})
dataset
})
}
# Shiny App
ui <- fluidPage(
fileInputUI("test"),
tableOutput("head_data")
)
server <- function(input, output, session) {
dataset <- fileInputServer("test")
output$head_data <- renderTable(head(dataset()))
}
shinyApp(ui, server)
I used modalDialog because I figured it to be the simplest approach to asking users about additional inputs to the read function for example the separator in case of read.csv or the startRow for read.xlsx etc.
Thanks for your replies