If Statement in Shiny based on values in reactive - r

Question

I am building an authentication part in my app by comparing the code sent in email and the code users submit. I have tried adding if-statement by using either in reactive(),isolate(), renderTable(). I either get the value should be in the reactive part error, or the app does not respond at all.
Below is what I have in Server.R, the app does not respond at all with no error.
shinyServer(function(input, output, session) {
myData <- reactive({
req(input$Id)
#connect to the database, get the data, res
#send an email with random number, rnd
list(res,rnd)
})
output$tbTable <- renderTable({req(input$Auth)
if (input$AuthCode==myData()$rnd) {
myData()$res
}
else{
as.data.frame(c("Authentication Failed"))
}
})
output$downloadData <- downloadHandler(
filename = function() {
paste(input$Id, " filname.xlsx", sep = "")
},
content = function(file) {
write.csv(myData(), file, row.names = FALSE)
}
)#this part need to depend on the if-statement as well
}
)
UI.R
ui <- shinyUI(fluidPage(title = "aaa",
titlePanel("aaa"),
sidebarLayout(
sidebarPanel(
textInput("Id", "Enter Acct Name below"),
submitButton(text="Submit"),
tags$hr(),
numericInput("AuthCode",label="Authentication",value=""),
actionButton("Auth",label="Submit"),
tags$hr(),
tags$hr(),
downloadButton("downloadData", "Download Data")
),
mainPanel(
tabsetPanel(
tabPanel("Data", tableOutput("tbTable"))
))
),
)
)

Answer 1

I think I've got the fixed to do what you want. Please check. I've done the following changes
Replaced your submitButton to actionButton as Acc and using observeEvent to call that.
The authentication is also now triggered by an observeEvent when the second button is clicked
Excel extension wouldn't work in write.csv so changed the extension.
server.R
shinyServer(function(input, output, session) {
# the first button will trigger this
observeEvent(input$Acc,{
# myData <- reactive({
req(input$Id)
#connect to the database, get the data, res
#send an email with random number, rnd
#list(res,rnd)
myData <<- list(res = 123,rnd = 345) #passing test value and storing it as global variable for accessing in other functions
# })
cat("mydata done")
})
# the second button will trigger this
observeEvent(input$Auth,{
output$tbTable <- renderTable({
#req(input$Auth)
if (input$AuthCode==myData$rnd) {
myData$res
}
else{
#as.data.frame(c("Authentication Failed"))
shiny::showModal(modalDialog(
title = "Important message",
"Authentication Failed!"
))
}
})
})
output$downloadData <- downloadHandler(
filename = function() {
paste(input$Id, " filname.csv", sep = "") #renamed it to csv because write.csv writes to csv not excel
},
content = function(file) {
write.csv(myData, file, row.names = FALSE)
}
)#this part need to depend on the if-statement as well
}
)
ui.R
ui <- shinyUI(fluidPage(title = "aaa",
titlePanel("aaa"),
sidebarLayout(
sidebarPanel(
textInput("Id", "Enter Acct Name below"),
actionButton("Acc",label="Click to send code"),
tags$hr(),
numericInput("AuthCode",label="Authentication",value=000),
actionButton("Auth",label="Submit"),
tags$hr(),
tags$hr(),
downloadButton("downloadData", "Download Data")
),
mainPanel(
tabsetPanel(
tabPanel("Data", tableOutput("tbTable"))
))
)
)
)