shinyapp: collecting data remotely

[youngforever]

Hi,

I am a shinyapp beginner. I want to create a survey based on shinyapp, and share this survey with others, the aim is to collect data from others. This means the data will be collected remotely. Now I create a shinyapp and host it on the shinyapps.io, when I click the link, fill out the survey, and click the submit button, the web showed that "Disconnected from the server". This issue may happen normally, but I want to know whether I can collect data from others based on shinyapps.io? or if I need to use other web servers such likle Amazon S3 to create a cloud server?

Thank you in advance

[andresrcs]

There is no persistent data storage in shinyapps.io but is completely possible to store the data to an external location as a database, Google Sheet, etc. If you show an example of your implementation we could give you more specific advice.

[youngforever]

Thank you so much!!!
For convenience, I provide a simple case.

library(shiny)
outputDir <- "responses"

# Define the fields we want to save from the form
fields <- c("text_demo")

saveData <- function(input) {
  # put variables in a data frame
  data <- data.frame(matrix(nrow=1,ncol=0))
  for (x in fields) {
    var <- input[[x]]
    if (length(var) > 1 ) {
      # handles lists from checkboxGroup and multiple Select
      data[[x]] <- list(var)
    } else {
      # all other data types
      data[[x]] <- var
    }
  }
  data$submit_time <- date()

# Create a unique file name
  fileName <- sprintf(
    "%s_%s.rds", 
    as.integer(Sys.time()), 
    digest::digest(data)
  )
  
  # Write the file to the local system
  saveRDS(
    object = data,
    file = file.path(outputDir, fileName)
  )
}


loadData <- function() {
  # read all the files into a list
  files <- list.files(outputDir, full.names = TRUE)
  
  if (length(files) == 0) {
    # create empty data frame with correct columns
    field_list <- c(fields, "submit_time")
    data <- data.frame(matrix(ncol = length(field_list), nrow = 0))
    names(data) <- field_list
  } else {
    data <- lapply(files, function(x) readRDS(x)) 
    
    # Concatenate all data together into one data.frame
    data <- do.call(rbind, data)
  }
  
  data
}
# Define questions
text_demo <- textInput("text_demo", "What is your favourite color?")
resetForm <- function(session) {
  updateTextInput(session, "text_demo", value = "")
}

# Set up questionnaire interface ----
ui <- fluidPage(
  title = "Questionnaire Framework",
  h3("My Survey"),
  p("Please fill out the following brief survey..."),
  fluidRow(
    column(width=6, text_demo)
  ),
  actionButton("submit", "Submit")
)

# Reactive functions ----
server = function(input, output, session) {
  # When the Submit button is clicked, save the form data
  observeEvent(input$submit, {
    saveData(input)
    resetForm(session)
    
    # thank the user
    n_responses <- length(list.files(outputDir))
    response <- paste0("Thank you for completing the survey! You are respondant ",
                       n_responses, ".")
    showNotification(response, duration = 0, type = "message")
  })
  
}
shinyApp(ui, server)

[andresrcs]

Saving a file for each response is an unnecessarily complicated approach and even harder to implement on shinyapps.io since storage is volatile and you don't have direct access to the server's file system. If you want to keep following this path, you could use googledrive package to store each file into your Google Drive account, but I think a better solution would be to store each response as a row on a spreadsheet, if you are interested in implementing this approach, take a look to the googlesheets4 package.

[youngforever]

Hi Andrescrs,
I see, I will have a try, thank you!!