Anonymise selected column in R shiny using sapply - shiny

Question

I am creating an R Shiny app, where a user can upload their own csv, and the app generates a synthetic dataset. I am trying to add an additional function where the user can select a column they wish to anonymise to make it a shareable file. The rest of the app is currently working, however when I select the column which I want to anonomise, when I press update, the datatable isn't refreshing.
Any help or insight here would be greatly appreciated! I've tried and tried to solve it, but am stuck.
A shortened/reproducible version of the code app is below
`
library(shiny)
library(synthpop)
library(DT)
library(tidyverse)
library(data.table)
library(rsconnect)
library(fontawesome)
library(DT)
library(htmltools)
library(shinythemes)
library(RcppRoll)
library(grid)
library(reactable)
library(shinydashboard)
library(shinydashboardPlus)
library(formattable)
library(dashboardthemes)
library(deidentifyr)
library(anonymizer)
library(digest)
# User interface
ui <- fluidPage(theme = shinytheme("cosmo"),
navbarPage("Synthetic data",
# Upload data tab
tabPanel("Upload data",
sidebarLayout(
sidebarPanel(width = 3,
h4(strong("Upload original data")),
br(),
fileInput(inputId = "datafile", label = "1. Upload a csv file then press 'Update' below.
Note, the larger your dataset, the longer it will take to load", multiple = FALSE, placeholder = "No file selected",
accept = c("text/csv", "text/comma-separated-values,text/plain", ".csv")),
actionButton(inputId = "update", label = "Update", icon = icon("fas fa-sync")),
br(),
br(),
h5(strong("2. To view and download the synthesised dataset, click on the 'Synthetic data' tab at the top"))),
mainPanel(dataTableOutput("table"), style = "font-size:80%"))),
# Synthetic data download
tabPanel("Synthetic data",
sidebarLayout(
sidebarPanel(width = 3,
h4(strong("Anonomise data?")),
br(),
uiOutput(outputId = "anon"),
br(),
actionButton(inputId = "update2", label = "Update", icon = icon("fas fa-sync"))),
mainPanel(dataTableOutput("synth"), style = "font-size:75%"))),
))
# Server function
server <- function(input, output, session) {
options(shiny.maxRequestSize=20*1024^2)
contentsrea <- reactive({
inFile <- input$datafile
if(is.null(inFile))
return(NULL)
dataset <- read_csv(inFile$datapath)
})
observeEvent(input$update, {
if(!is.null(input$datafile)){
original <- read_csv(input$datafile$datapath)
my.seed <- 17914709
synResult <- syn(original, seed = my.seed, maxfaclevels = 150)
# Synthetic data
df <- synResult$syn
# Add 'SYNTH' to column headings
colnames(df) <- paste("SYNTH", colnames(df), sep="_")
# Variable dropdown to anonomise data
output$anon <- renderUI({
selectInput(inputId = "anon",
label="1. Select the variable you'd like to anonomise (i.e., athlete name). If not necessary, leave as blank",
choices = c(" ", colnames(df)),
selected = NULL)
})
## Original
output$table <- DT::renderDataTable(original,
caption = htmltools::tags$caption(
style = 'caption-side: top; text-align: left; color: black; font-size:140%',
h3(strong("Original data"))), server = FALSE, rownames=FALSE,
options = list(bFilter=0, iDisplayLength=18,
columnDefs = list(list(className = 'dt-center', targets = '_all')),
dom = 'frtip'))
# Synthetic dataset
output$synth <- DT::renderDataTable(df,
caption = htmltools::tags$caption(
style = 'caption-side: top; text-align: left; color: black; font-size:140%',
h3(strong("Simulated synthetic data"))),
server = FALSE, rownames=FALSE, extensions = c("Buttons"),
options = list(iDisplayLength=18, bFilter=0,
columnDefs = list(list(className = 'dt-center', targets = '_all')),
dom = 'Bfrtip'))
}})
}
# Synthetic dataset with update for anon
observeEvent(input$update2, {
if(!is.null(input$datafile)){
output$synth <- DT::renderDataTable({
# Anonomise
df$ID <- sapply(input$anon, digest, algo = "crc32")
datatable(df,
caption = htmltools::tags$caption(
style = 'caption-side: top; text-align: left; color: black; font-size:140%',
h3(strong("Simulated synthetic data"))),
server = FALSE, rownames=FALSE, extensions = c("Buttons"),
options = list(iDisplayLength=18, bFilter=0,
columnDefs = list(list(className = 'dt-center', targets = '_all')),
dom = 'Bfrtip'))
})
}})
# Run the app ----
shinyApp(ui, server)
`
I have tried removing the update button ans using a reactive table, as well as other anonomise functions. I am completely stuck.