Online Banking System using R

The provided code implements a basic online banking system using R and Shiny.

Here's a brief description of its components

• User Interface (UI): The UI is created using Shiny's UI functions. It includes input fields for the user to enter their account details and select banking operations like deposit, withdrawal, and balance inquiry.

• Server Logic: The server logic is implemented using Shiny's server functions. It handles user inputs; performs banking operations based on the user requests and updates the UI with results.

Features:

• Deposit: Users can deposit funds into their account by entering the deposit amount and clicking the "Deposit" button.

• Withdrawal: Users can withdraw funds from their account by entering the withdrawal amount and clicking the "Withdraw" button. The system checks for a sufficient balance before processing the withdrawal.

• Balance Inquiry: Users can check their account balance by clicking the "Check Balance" button.

Example

library(shiny)

# Simulated user data
users <- data.frame(
  username = c("user1", "user2", "user3"),
  password = c("password1", "password2", "password3"),
  balance = c(1000, 2000, 500)
)
ui <- fluidPage(
  titlePanel("The Online Banking System"),
  sidebarLayout(
    sidebarPanel(
      textInput("username", "Username"),
      passwordInput("password", "Password"),
      actionButton("login", "Login")
    ),
    mainPanel(
      textOutput("login_message"),
      conditionalPanel(
        condition = "input.login",
        textInput("recipient", "Recipient"),
        numericInput("amount", "Amount", value = 0),
        actionButton("transfer", "Transfer"),
        verbatimTextOutput("transaction_message")
      )
    )
  )
)
# Server logic
server <- function(input, output, session) {
  # Track logged in user
  loggedInUser <- reactiveVal(NULL)
  # Login action
  observeEvent(input$login, {
    user <- users[users$username == input$username & users$password == input$password, ]
    if (nrow(user) == 1) {
      loggedInUser(user$username)
      output$login_message <- renderText({
        paste("Welcome, ", user$username, "!")
      })
    } else {
      output$login_message <- renderText("Invalid username or password")
    }
  })
  # The Transfer the action
  observeEvent(input$transfer, {
    if (!is.null(loggedInUser())) {
      recipient <- input$recipient
      amount <- input$amount
      user <- users[users$username == loggedInUser(), ]
      recipient_user <- users[users$username == recipient, ]
      if (nrow(recipient_user) == 1 && amount > 0 && user$balance >= amount) {
        users[users$username == loggedInUser(), "balance"] <- user$balance - amount
        users[users$username == recipient, "balance"] <- recipient_user$balance + amount
        output$transaction_message <- renderPrint({
          paste("The Transfer successful! New balance:", users[users$username == loggedInUser(), "balance"])
        })
      } else {
        output$transaction_message <- renderPrint("Transfer failed")
      }
    }
  })
}
# Run
shinyApp(ui, server)

Output