Local WebR REPL

This project is a web-based R REPL (Read-Eval-Print Loop) built using WebR. It allows users to execute R code directly in the browser, upload CSV files for analysis, and generate plots dynamically.

Current version is hosted at: https://webr-test2.netlify.app

Features

1. Run R Code Directly in Browser:

   • A simple interface to input R commands and view the results

2. Upload CSV Files:

   • Upload CSV files for analysis in R
   • Automatically detects and parses date strings (e.g., YYYY-MM-DD)

3. Generate Plots:

   • Generate and display PNG plots based on the uploaded data
   • Automatically handles numeric and date-based data

4. Responsive Design:

   • The interface adjusts to fit various screen sizes

Getting Started

Prerequisites

1. Modern Browser:

   • Ensure your browser supports WebAssembly (WASM) and ES6 modules (e.g., Chrome, Firefox, Edge)

2. Hosting:

   • Use a local development server or a hosting platform like Netlify to serve the files, as Cross-Origin Isolation is required for WebR

Setup

1. Clone this repository:

git clone https://github.com/yourusername/webr-repl.git
cd webr-repl

2. Start a local server:

python3 -m http.server

3. Open http://localhost:8000 in your browser

Usage

Run R Code

• Enter any valid R code (e.g., 1 + 1, summary(cars)) in the input box and click "Run"

Upload a CSV File

• Click the "Choose File" button and upload a .csv file (e.g., temperature_data.csv)

Display Data or Generate Plot

After uploading a file:

• Click "Display Head" to view the first few rows of the dataset
• Click "Create Plot" to generate a PNG plot of the data

View Plot

The generated plot will appear as an image below the REPL output

Example CSV File: temperature_data.csv

Here's an example CSV file you can use to test the application:

Date,Temperature
2025-01-01,3.2
2025-01-02,4.1
2025-01-03,2.8
2025-01-04,3.5
2025-01-05,4.0
2025-01-06,3.9
2025-01-07,5.2

Technical Overview

HTML

Provides the interface for:

• Inputting R code
• Uploading CSV files
• Displaying results and plots

JavaScript

1. WebR Initialization:

   • Initializes WebR for running R code in the browser

2. File Handling:

   • Processes uploaded CSV files and passes them to R

3. Plotting:

   • Generates and displays PNG plots using the R png() function

4. Error Handling:

   • Provides detailed error messages for debugging invalid inputs or unsupported operations

Known Issues

1. Cross-Origin Isolation:

   • Ensure the project is served from a properly configured server to enable WebR functionality

2. File Size Limits:

   • Large CSV files may take longer to process or fail due to memory limitations in the browser

Future Enhancements

1. Dynamic Column Selection:

   • Allow users to select specific columns for plotting

2. Support for Additional File Formats:

   • Expand support to .txt and .json files

3. Improved Plot Customization:

   • Add user controls for customizing plot aesthetics (e.g., colors, labels)

4. Persistent State:

   • Cache uploaded files in the browser for reuse

Contributing

1. Fork the repository
2. Create a new branch (git checkout -b feature-name)
3. Commit your changes (git commit -m 'Add some feature')
4. Push to the branch (git push origin feature-name)
5. Open a pull request

License

This project is licensed under the MIT License. See the LICENSE file for details.