Using R Shiny to Add a Sheet to a Pre-Existing Excel File with Action Button

In this article, we will explore how to use R Shiny to add a new sheet to a pre-existing Excel file using an action button. We will go through the process of creating a Shiny app that allows users to select an Excel file, and then add a new sheet to it.

Introduction

Excel files are widely used in various industries for data storage and analysis. However, working with Excel files can be challenging, especially when it comes to modifying existing files. R Shiny provides a convenient way to create web-based applications that interact with Excel files, allowing users to perform tasks such as adding new sheets, updating data, and more.

In this article, we will focus on using R Shiny to add a new sheet to an existing Excel file using an action button. We will cover the process of creating a Shiny app, writing code to read and write Excel files, and implementing the action button functionality.

Prerequisites

To follow along with this article, you should have:

• R installed on your system
• R Studio or another text editor for writing code
• A basic understanding of R programming language and Shiny framework

Step 1: Install Required Libraries

Before we begin, make sure to install the required libraries. We will need xlsx package to read and write Excel files.

# Install xlsx library
install.packages("xlsx")

Alternatively, you can also use openxlsx and readxl packages for reading Excel files.

Step 2: Create a Shiny App

Create a new R file (e.g., shiny_app.R) and add the following code to create a basic Shiny app:

# Load required libraries
library(shiny)
library(xlsx)
library(openxlsx)

# Define UI
ui <- fluidPage(
  titlePanel("Excel File App"),
  sidebarLayout(
    sidebarPanel(
      fileInput(inputId = "file", label = "Read File Here", accept = c(".xlsx")),
      actionButton(inputId = "run", label = "Add New Sheet")
    ),
    mainPanel(dataTableOutput(outputId = "table1"))
  )
)

# Define server
server <- function(input, output) {
  # Initialize dataset
  data <- reactive({
    infile <- input$file
    if (is.null(infile)) return(NULL)
    
    # Read Excel file
    if (grepl(infile, pattern = ".xlsx") == T) {
      data <- read.xlsx(infile$datapath)
    } else if (grepl(infile, pattern = ".csv") == T) {
      data <- read.csv(infile$datapath)
    }
    
    return(data)
  })
  
  # Render table
  output$table1 <- renderDataTable({
    datasetInput()
  })
  
  # Observe event on run button
  observeEvent(input$run, {
    infile <- input$file
    testfile <- infile[1]
    filepath <- gsub(pattern = "0.xlsx", replacement = "", x = filepath)
    
    # Set working directory
    setwd(dir = filepath)
    
    # Write new sheet to Excel file
    write.xlsx('new_data', testfile, sheetName="New_Sheet3", append=TRUE)
  })
}

# Run app
shinyApp(ui = ui, server = server)

This code creates a basic Shiny app with a title panel, sidebar layout, and a main panel displaying a table. The app also includes a file input for selecting an Excel file and an action button to add a new sheet.

Step 3: Add Action Button Functionality

In the server function, we added an observeEvent event handler to respond to the run button click event. When the button is clicked, the code retrieves the selected file path, sets the working directory, and writes a new sheet to the Excel file using write.xlsx.

Step 4: Test the App

Save the shiny_app.R file and run it in R Studio or another text editor. Open the app in your web browser and select an Excel file using the file input. Click on the “Add New Sheet” button, and verify that a new sheet is added to the Excel file.

Conclusion

In this article, we demonstrated how to use R Shiny to add a new sheet to an existing Excel file using an action button. We covered the process of creating a Shiny app, writing code to read and write Excel files, and implementing the action button functionality.

By following these steps, you can create your own Shiny app that allows users to interact with Excel files and perform various tasks such as adding new sheets, updating data, and more.

Example Use Cases

• Add a new sheet to an existing Excel file based on user input.
• Update data in an existing Excel file based on user input.
• Create a dashboard with multiple Excel files that can be interacted with using Shiny.

Note: This is a basic example, and you may need to modify the code to fit your specific use case. Additionally, make sure to test your app thoroughly to ensure it works as expected.

Last modified on 2024-04-09