R shiny: save chosen factors from input data - r

Question

I have a question regarding R shiny and the observ function. Is it possible to save the selected factors and the state of the work? For Example I created a programm which can choose colnames from the input data. After using bookmark and reopening the programm with the link in the browser the input data are loaded but the select factors of the colnames are reset. But I want to save the chosen colnames. Has anyone an idea? Thank you for your help!
ui <- function(request) {
fluidPage(
sidebarLayout(
sidebarPanel(
radioButtons(
"fileType_Input",
label = h5(""),
choices = list(".csv" = 1, ".xlsx" = 2),
selected = 1,
inline = TRUE
),
fileInput('file1', '' ),
selectInput("letters", label=NULL, factors, multiple = TRUE),
bookmarkButton()
),
mainPanel(
tableOutput("contents")
)
)
)
}
server <- function(input, output,session) {
myData <- reactive({
inFile <- input$file1
# Get the upload file
if (is.null(inFile)) {
return(NULL) }
if (input$fileType_Input == "1") {
read.csv2(inFile$datapath,
header = TRUE,
stringsAsFactors = FALSE)
} else {
read_excel(inFile$datapath)
}
})
observe({
if(is.null(input$letters)){
data <- myData()
if(is.null(data)){
}else{
factors <- colnames(data)
t$choices <- input$letters # append(u$choices,input$letters2)
updateSelectInput(session, "letters",
choices = factors #[!factors2 %in% u$choices)]
)}
}
})
#Display all input Data
output$contents <- renderTable(digits = NULL,{
df <-myData()
df
})
}
enableBookmarking("server")
shinyApp(ui, server)

Answer 1

You can save all needed inputs in a file, and then reapply them with functions like updateRadioButtons() and others.
Saving it to the file could look like this:
observeEvent(input$someRadioButton, {
states <- list()
states$someRadioButton <- input$someRadioButton
#you can save all the needed inputs like this
...
save(states, file = paste0(getwd(), "/myfile"))
})