How to loop through multiple upload widegets in shiny? - r

Question

I want to create multiple fileInput function to allow users to upload files. The main reason I am creating multiple upload widgets is because I want to allow users to upload through different path. What I am trying to accomplish here is to loop through all the fileInputs and save all the files into one dataframe but not able to do it in example of my code.
library(shiny)
library(data.table)
library(DT)
n_attachments <- sprintf("file%s",seq(1:2))
ui <- fluidPage(
titlePanel('File download'),
sidebarLayout(
sidebarPanel(
textInput("LOAN_NUMBER", label = "Fannie Mae Loan Number", placeholder = "Please enter loan #")
, textInput("REO_ID", label = "REO Number", placeholder = "Please enter REO #")
, fileInput("file1", "Attachments1", accept = c("text/csv", "text/comma-separated-values,text/plain",".csv", ".pdf", ".doc", ".xlsx"), multiple = TRUE)
, fileInput("file2", "Attachments2", accept = c("text/csv", "text/comma-separated-values,text/plain",".csv", ".pdf", ".doc", ".xlsx"), multiple = TRUE)
, textOutput('text')
),
mainPanel(
DT::dataTableOutput("table"), tags$hr()
)
)
)
server <- function(input, output) {
bin_data <- reactive({
attachement_data <- data.frame(ATTACHMENT = character(), FILENAME = character(), LOAN_NUMBER = character(), REO_ID = character())
for(x in n_attachments)
{
output$text <- renderText({ input$x })
req(input$x)
# binary_data <- paste(readBin(input$file1$datapath, what="raw", n=1e6), collapse="-")
# attachment_info <- data.frame(ATTACHMENT = binary_data, FILENAME = paste0(input$file1$name))
# attachment_info
binary_data=list()
filenames=list()
for(i in 1:length(input$x[,1])){
binary_data[[i]] <- paste(readBin(input$x[[i, 'datapath']], what = "raw", n=1e6), collapse = "-")
filenames[[i]] <- input$x[[i, 'name']]
}
bin_data_frame <- data.frame(ATTACHMENT = as.character(unlist(binary_data)), FILENAME = as.character(unlist(filenames)))
bin_data_frame$LOAN_NUMBER <- input$LOAN_NUMBER
bin_data_frame$REO_ID <- input$REO_ID
attachement_data <- rbind(attachement_data, bin_data_frame)
}
save(attachement_data, file="attachement_data.RData")
attachement_data
})
output$table <- DT::renderDataTable({
bin_data()
})
}
shinyApp(ui = ui, server = server)

Answer 1

ok I think I figured it out, I have to use input[[x]] instead of input$x, and I added couple lines to check how many fileinputs are uploaded.
server <- function(input, output) {
bin_data <- reactive({
attachement_data <- data.frame(ATTACHMENT = character(), FILENAME = character(), LOAN_NUMBER = character(), REO_ID = character())
k <- 0
for(x in n_attachments)
{
if(!is.null(input[[x]]))
{
k = k + 1
}
}
for(x in n_attachments[0:k])
{
if(!is.null(input[[x]]))
{
output$text <- renderText({ input[[x]] })
req(input[[x]])
# binary_data <- paste(readBin(input$file1$datapath, what="raw", n=1e6), collapse="-")
# attachment_info <- data.frame(ATTACHMENT = binary_data, FILENAME = paste0(input$file1$name))
# attachment_info
binary_data=list()
filenames=list()
for(i in 1:length(input[[x]][,1])){
binary_data[[i]] <- paste(readBin(input[[x]][[i, 'datapath']], what = "raw", n=1e6), collapse = "-")
filenames[[i]] <- input[[x]][[i, 'name']]
}
bin_data_frame <- data.frame(ATTACHMENT = as.character(unlist(binary_data)), FILENAME = as.character(unlist(filenames)))
bin_data_frame$LOAN_NUMBER <- input$LOAN_NUMBER
bin_data_frame$REO_ID <- input$REO_ID
attachement_data <- rbind(attachement_data, bin_data_frame)
}
}
save(attachement_data, file="attachement_data.RData")
attachement_data
})
output$table <- DT::renderDataTable({
bin_data()
})
}
shinyApp(ui = ui, server = server)