Winston Chang

ggplot2

An implementation of the Grammar of Graphics in R

Shiny

Easy interactive web applications with R

Quarto

Open-source scientific and technical publishing system built on Pandoc

Positron

Positron, a next-generation data science IDE

rmarkdown

Dynamic Documents for R

devtools

Tools to make an R developer’s life easier

shiny-examples

Shiny for Python

Easy interactive web applications with Python

ShinyConf 2025

ShinyConf is the biggest virtual Shiny event hosted by Appsilon

Positron AI Session (George Stagg, Winston Chang, Tomasz Kalinowski, Carson Sievert) | posit::conf

George Stagg, Winston Chang, and Tomasz Kalinowski introduce AI capabilities in Positron, including Positron Assistant, a tool still in preview that enhances coding and data analysis. 0:00 Introduction to Posit’s approach to AI 0:23 George Stagg: Positron Assistant 11:03 Winston Chang: Databot 21:30 Tomasz Kalinowski: ragnar 31:13 Carson Sievert: chatlas 41:42 Q&A posit::conf(2025) Subscribe to posit::conf updates: https://posit.co/about/subscription-management/

Carson Sievert, George Stagg, Tomasz Kalinowski, Winston Chang

Web applications with Shiny and React and AI (Winston Chang, Posit) | posit::conf(2025)

Web applications with Shiny and React (and AI) Speaker(s): Winston Chang If you’ve ever wanted to have complete control over the UI for a Shiny application, this talk might be for you. In this talk I’ll show how to integrate a back end written in Shiny (for R or Python) with a front end written in React.js. This lets you combine Shiny’s reactivity with the flexibility of the React web development ecosystem. In the past, writing a front end in React was a large time investment, and would be reserved only for a serious project. However, with today’s agentic AI coding tools, it can make sense to create a React front end even for smaller-scale applications. But even with AI involved, you will still need to know some React or be willing to learn about it. GitHub Repo - https://github.com/wch/shiny-react CLI tool - https://github.com/wch/create-shiny-react-app Anthropic Dashboard - https://github.com/wch/anthropic_dashboard posit::conf(2025) Subscribe to posit::conf updates: https://posit.co/about/subscription-management/

Winston Chang

Winston Chang - Building ML and AI apps with Shiny for Python

In the last few months, the best LLMs have taken a big step forward in their ability to help write code. We’ve been building a tool that uses an LLM to help you learn Shiny and build Shiny applications much faster than ever before. If you feel like you don’t have the time to invest in learning Shiny, this might change your mind. You’ll get up and running with Shiny in no time, and you’ll be able to learn from the AI as you go. If you already know Shiny, you’ll be able to dramatically accelerate your development process, and you’ll find yourself trying out new things that wouldn’t have been worth the effort before. Talk by Winston Chang

Winston Chang

Shiny Assistant: Prototype and build Shiny applications with the help of AI | Winston Chang | Posit

Have you ever had an idea for a great web application with Shiny but felt something holding you back from getting started? Maybe it’s that you don’t know where to start, or that you don’t know which packages use to build the app, or maybe it’s just that you can’t muster the energy to get started. Sometimes you just need a little help to get unstuck. We’re excited to announce a new addition to the Shiny ecosystem that can help: Shiny Assistant. Try it out here, free: https://gallery.shinyapps.io/assistant/ Get started with Shiny for R and Python: https://shiny.posit.co

Winston Chang

Shiny Assistant

Prototype and build Shiny applications with the help of AI

Winston Chang

How to write and deploy a Python web app with Shiny Express and Posit Team

Winston Chang at Posit joined us to share a quicker and simpler way of writing Shiny applications in Python, called Shiny Express With Shiny Express you can create interactive data dashboards and data-driven applications faster than ever. Helpful resources: ️ Introducing Shiny Express: https://shiny.posit.co/blog/posts/shiny-express/ ️ Shinylive: https://shinylive.io/py/examples/ ️ Component Gallery: https://shiny.posit.co/py/components/ ️ VS Code Shiny extension: https://marketplace.visualstudio.com/items?itemName=Posit.shiny-python ️ Q&A recording: https://youtube.com/live/zg4LP4lkihM?feature=share rsconnect-python package: https://pypi.org/project/rsconnect-python/ ️ Follow-up links: Event Survey: https://forms.gle/8AcMAnjfPFSTQZJK6 Posit Team: https://posit.co/products/enterprise/team/ Request evaluation: pos.it/chat-with-us Posit Team demo resources: pos.it/demo-resources What will you learn? If you’re new to Shiny → you’ll get started writing and deploying your first Shiny Express application in Python. If you already know Shiny → you’ll see how Shiny Express can make your development experience quicker and more efficient. Happy with the way things are? No need to change what you’re doing! We think of Shiny Express and Shiny Core as complementary, and intend to support both syntaxes indefinitely. Last month’s Workflow with Posit Team Demo featured Shiny in R and used bslib for custom theming, which you can check out here in the recording: https://youtu.be/O6WLERr5bKU?feature=shared LIVE Q&A ROOM for ~11:30 am on Feb 28th: https://youtube.com/live/zg4LP4lkihM?feature=share There is no need to register; join us here on YouTube at the time above or you can add to your calendar using the link below: pos.it/team-demo We host these Workflow Demos on the last Wednesday of every month, so you can use the link above to add the recurring event as well. #python

Winston Chang

AI and Shiny for Python: Unlocking New Possibilities - posit::conf

Presented by Winston Chang In the past year, people have come to realize that AI can revolutionize the way we work. This talk focuses on using AI tools with Shiny for Python, demonstrating how AI can accelerate Shiny application development and enhance its capabilities. We’ll also explore Shiny’s unique ability to interface with AI models, offering possibilities beyond Python web frameworks like Streamlit and Dash. Learn how Shiny and AI together can empower you to do more, and do it faster. Presented at Posit Conference, between Sept 19-20 2023, Learn more at posit.co/conference.# Talk Track: I can’t believe it’s not magic: new tools for data science. Session Code: TALK-1153

Winston Chang

20 questions and AI chat bots - posit::conf(2023)

Presented by Winston Chang Presented at Posit Conference, between Sept 19-20 2023, Learn more at posit.co/conference.# Talk Track: I can’t believe it’s not magic: new tools for data science. Session Code: TALK-1153

Winston Chang

Shiny for Python 0.4.0

Better tables and sidebars!

Winston Chang

Keynote, Winston Chang: Lessons and opportunities with Shiny for Python

About the keynote: For the past 10 years, the R community has been able to use Shiny to bring interactive data analyses to the web. Last summer, we announced that Shiny would also be available to for Python. In this talk, I’ll discuss what we’ve learned along the way, as well as the opportunities that Shiny for Python opens up. We are at the beginning of an exciting new era for Shiny, and I hope that community of old and new Shiny users make the most of it! Speaker’s bio: Winston Chang is a software engineer at Posit, PBC, who has served in various roles on the Shiny team, including team lead. He has contributed to many widely-used packages in the R ecosystem, including Shiny, devtools, and ggplot2, and is the creator of several packages, including shinydashboard, R6, and profvis. Recently he has been busy working on Shiny and Shinylive for Python. Winston has a Ph.D. in psychology from Northwestern University and is the author of the R Graphics Cookbook, published by O’Reilly Media

Shiny Team, Winston Chang

AI chat apps with Shiny for Python

The easiest way to build an AI chat app

Winston Chang

Shiny for Python out of alpha

Shiny for Python has moved from alpha to general availability

Winston Chang

Shinylive Extension

With Shinylive, you can embed Shiny for Python applications into Quarto documents and run the entire application (including the Python runtime) inside the user’s web browser

Winston Chang

Winston Chang | Running Shiny without a server | RStudio (2022)

Shiny for Python has the ability to be deployed without a server that runs Python. These applications can be served by any web hosting service. They are easily deployed and can scale to handle large amounts of traffic. This mode of deployment is called Shinylive. It works by running Python in the user’s web browser, using Pyodide, which is a version of Python that is compiled to WebAssembly. Shinylive opens up new possibilities for how Shiny applications can be used. In this talk I discuss the advantages and the limitations of Shinylive applications. Session: Some of my best friends use Python

Winston Chang

Plot Outputs in Shiny for Python || Winston Chang || RStudio

Shiny makes it easy to build interactive web applications with the power of Python’s data and scientific stack. You can try out Shiny for Python without installing a single thing… All in the browser. Learn more about Shiny for Python: https://shiny.rstudio.com/py/ Check out our interactive Shiny for Python examples: https://shinylive.io/py/examples/ Content: Winston Chang (@winston_chang)

Winston Chang

Multiple Inputs in Shiny for Python || Winston Chang || RStudio

Shiny makes it easy to build interactive web applications with the power of Python’s data and scientific stack. You can try out Shiny for Python without installing a single thing… All in the browser. Learn more about Shiny for Python: https://shiny.rstudio.com/py/ Check out our interactive Shiny for Python examples: https://shinylive.io/py/examples/ Content: Winston Chang (@winston_chang)

Winston Chang

Getting Started with Shiny for Python - in the browser! || Winston Chang || Posit

Shiny makes it easy to build interactive web applications with the power of Python’s data and scientific stack. You can try out Shiny for Python without installing a single thing… All in the browser. Learn more about Shiny for Python: https://shiny.rstudio.com/py/ Check out our interactive Shiny for Python examples: https://shinylive.io/py/examples/ Content: Winston Chang (@winston_chang)

Winston Chang

Hey Shiny Team, what are some of your biggest learnings from 2022? || Shiny Developers || RStudio

BIG THINGS happened on the Shiny team in 2022! Our team built out a new Shiny UI Editor, Shiny for Python, and Shiny for Python in the browser using WebAssembly. So we asked some of our Developers what their biggest learnings have been from building these products! Learn more about Shiny for Python: https://shiny.rstudio.com/py/ Content: Winston Chang (@winston_chang), Carson Sievert (@cpsievert), Nick Strayer (), Michael Chow (@chowthedog) Producer: Jesse Mostipak (@kierisi) Video editing + motion design: Tony Pelleriti (@TonyPelleriti)

Carson Sievert, Michael Chow, Nick Strayer, Shiny Team, Winston Chang

An Interview with Winston Chang: Building a Wordle App with Shiny for Python || RStudio

Shiny makes it easy to build interactive web applications with the power of Python’s data and scientific stack. Learn more about Shiny for Python: https://shiny.rstudio.com/py/ Check out our interactive Shiny for Python examples: https://shinylive.io/py/examples/ Content: Winston Chang (@winston_chang) + Jesse Mostipak (@kierisi) Producer: Jesse Mostipak (@kierisi) Editing and Motion Design: Tony Pelleriti (@TonyPelleriti)

Winston Chang

A Beginner’s Guide to Shiny for Python || Winston Chang || Posit

Shiny makes it easy to build interactive web applications with the power of Python’s data and scientific stack. Learn more about Shiny for Python: https://shiny.rstudio.com/py/ Check out our interactive Shiny for Python examples: https://shinylive.io/py/examples/ Content: Winston Chang (@winston_chang) Producer: Jesse Mostipak (@kierisi) Editing and Motion Design: Tony Pelleriti (@TonyPelleriti)

Winston Chang

Winston Chang || Part III: Adding a Keyboard to a Wordle Shiny App || RStudio

00:00 Introduction 00:25 Setting up a keyboard 00:54 Using an HTML p tag to print out letter indicators 01:56 Back to our keyboard! 03:44 Setting up a search and replace 06:32 Removing letters using regular expressions 08:43 Making guesses a reactiveVal() 11:00 Avoiding an infinite loop with reactiveVal() In Part III of this four-part series, Winston walks through how to build a keyboard in a Shiny Wordle app. Code + word list: https://github.com/wch/shiny-wordle Check out the full Shiny app here: https://winston.shinyapps.io/wordle/ You can learn more about Shiny here: https://shiny.rstudio.com/ Got questions? The RStudio Community site is a great place to get assistance: https://community.rstudio.com/ Content: Developer (@winston_chang) Animation, design, and editing: Jesse Mostipak (@kierisi) Wordle: https://www.powerlanguage.co.uk/wordle/

Winston Chang

Winston Chang || Part II: Handling Duplicate Letters in a Shiny Wordle App || RStudio

00:00 Introduction 00:52 Setting up the problem with duplicate letters 02:08 Coding the first pass for exact matches in the correct position 06:29 Re-evaluating how to approach the problem 12:28 Removing only one instance of a letter 13:56 Testing our code 14:54 Setting up the second pass 19:08 Scoping with a double arrow 19:52 Debugging with a browser() statement 21:28 Checking our code In Part II of this four-part series, Winston walks through how to handle duplicate letters when building your Shiny Wordle app. Code + word list: https://github.com/wch/shiny-wordle Check out the full Shiny app here: https://winston.shinyapps.io/wordle/ You can learn more about Shiny here: https://shiny.rstudio.com/ Got questions? The RStudio Community site is a great place to get assistance: https://community.rstudio.com/ Content: Developer (@winston_chang) Animation, design, and editing: Jesse Mostipak (@kierisi) Wordle: https://www.powerlanguage.co.uk/wordle/

Winston Chang

Winston Chang || Part I: Build a Basic Wordle App with Shiny || RStudio

00:00 Introduction 00:12 What is Wordle? 00:36 The Wordle app we’ll build by the end of this four-part series 01:08 How to approach the problem 01:38 Word list (link to file below) 01:52 UI function with fluidPage() 02:24 Print out what player guesses using verbatimTextOutput() 03:36 Run app in Viewer Panel 04:04 Adding an action button with actionButton() 04:29 Using bindEvent() with actionButton() 06:02 Limiting guesses to words with five characters 07:40 Using req() and cancelOutput() 08:54 Incorporating the word list 10:13 Matching player guess to word list 11:06 Matching player guess to target word 13:50 Writing a function to match guess to target word with feedback 18:15 Checking word length between guess and target 23:02 Why we’re using intermediary functions 28:51 Printing formatted letter information In Part I of this four-part series, Winston walks through how to build a basic Wordle app using Shiny! Code + word list: https://github.com/wch/shiny-wordle Check out the full Shiny app here: https://winston.shinyapps.io/wordle/ You can learn more about Shiny here: https://shiny.rstudio.com/ Got questions? The RStudio Community site is a great place to get assistance: https://community.rstudio.com/ Content: Developer (@winston_chang) Animation, design, and editing: Jesse Mostipak (@kierisi) Wordle: https://www.powerlanguage.co.uk/wordle/

Winston Chang

Winston Chang | Making Shiny apps faster with caching | RStudio

Shiny’s 1.6 has a new function, bindCache(), which makes it easy to dramatically speed up reactive expressions and output rendering functions. This allows many applications to scale up to serve several times more users without an increase in server resources. Note: Shiny 1.6.0 isn’t yet on CRAN, but will be in the next few days. In the meantime, you can install it with: remotes::install_github(““ rstudio/shiny@rc-v1.6.0 "”) About Winston: Winston is a software engineer at RStudio. He holds a Ph.D. in psychology from Northwestern University and is the author of R Graphics Cookbook, published by O’Reilly Media

Winston Chang

Introducing Shiny App Stories

App Stories are a bit different from the User Showcase: an App Story will center around a Shiny application, but the application will be designed specifically to show off specific features, and it will also include explanations of how to use those features

Winston Chang, Nick Strayer

Shiny 1.6

Shiny 1.6 is now on CRAN! This release includes significant improvements to theming, caching, accessibility, and more

Carson Sievert, Winston Chang, Barret Schloerke

Winston Chang | Asynchronous programming in R | RStudio (2020)

Writing regular R code is straightforward: you tell R to do something, it does it, and then it returns control back to you. This is called synchronous programming. However, if you use R to coordinate threads, processes, or network communication, the regular model may be unable to do what you want, or it may only be able to do it with a significant performance penalty. In this talk I'll explain how asynchronous programming with the later package can handle these kinds of programming problems. I'll also show how to provide a synchronous interface for asynchronous code, so that users will have a simple, familiar way to use your code. Materials - github repo

Winston Chang

Shiny 1.4.0

Shiny 1.4.0: trailing commas now work in UI functions like div() and span()

Winston Chang

Intermediate Shiny 2-Day-Workshop - rstudio::conf(2019L)

What is the 2-day Intermediate Shiny Workshop? That’s a great question, I’m glad you asked…. Register at https://rstd.io/conf Learn more at https://rstd.io/conf-agenda Intermediate Shiny Workshop - 2 Days This two-day workshop is designed by Shiny author Joe Cheng for the experienced Shiny developer. By taking this workshop, you’ll improve your understanding of shiny’s foundations and learn how to make the most of reactive programming, techniques for extending and improving UI, techniques for debugging and tools for modularizing applications. By the end of the two days, you’ll be able to push the envelope of what you and your organizations can do with Shiny. You should take this workshop if you are already familiar with the basics of shiny and you have built your own simple applications. This course is led by friend of RStudio and Education Practice Lead at RStudio Certified Partner Mango Solutions, Aimee Gott. Winston Chang, RStudio Data Scientist, Developer, and author of the R Graphics Cookbook will join Aimee to provide hands-on advice and answers to the Shiny application development questions that stump you. Speakers: Aimee Gott (Mango Solutions), with Winston Chang (RStudio)

Joe Cheng, Winston Chang

Shiny and R to Build Dynamic Dashboards

In a static report, you answer known questions. With a dynamic report, you give the reader the tools to answer their own questions. Unleash the full flexibility of analytic app development with Shiny. In this talk, Winston Chang will discuss how to use R and Shiny to quickly create data dashboards. You’ll also get a glimpse of some new features in Shiny for presenting and interacting with data. He will also demonstrate how you can easily deploy apps to the web via RStudio’s hosting service shinyapps.io. Related blog post: https://blog.rstudio.com/2017/05/18/shinydashboard-0-6-0/

Winston Chang

Shiny 1.0.4

Shiny 1.0.4: drag-and-drop file inputs, dynamic tab management, and onStop callbacks

Winston Chang

The R6 Class System by Winston Chang from useR! Brussels 2017

R6 is an implementation of a classical object-oriented programming system for R. In classical OOP, objects have mutable state and they contain methods to modify and access internal state. This stands in contrast with the functional style of object-oriented programming provided by the S3 and S4 class systems, where the objects are (typically) not mutable, and the methods to modify and access their contents are external to the objects themselves. R6 has some similarities with R’s built-in Reference Class system. Although the implementation of R6 is simpler and lighter weight than that of Reference Classes, it offers some additional features such as private members and robust cross-package inheritance. In this talk I will discuss when it makes sense to use R6 as opposed to functional OOP, demonstrate how to use the package, and explore some of the internal design of R6

Winston Chang

shinythemes 1.1.1

shinythemes 1.1.1 adds new Bootstrap themes from bootswatch.com and a live theme selector for Shiny apps

Winston Chang

Shiny 0.14

Shiny 0.14 adds bookmarkable state, notifications, modal dialogs, insertUI/removeUI, and database connection docs

Winston Chang

Shiny 0.13.0

Shiny 0.13.0 introduces Gadgets for interactive tools, HTML templates, modules for managing complexity, and stack traces

Winston Chang

Shiny 0.11, themes, and dashboard

Shiny 0.11 migrates to Bootstrap 3, adds improved sliders, passwordInput(), observeEvent(), plus new shinythemes and shinydashboard packages

Winston Chang

ggvis 0.4

ggvis 0.4 adds layer_boxplots(), better error handling, and more reliable interactive graphics with dynamic data

Winston Chang

Introducing ggvis

Introducing ggvis: grammar of graphics meets interactivity. Create reactive, browser-rendered plots with Shiny integration

Winston Chang

Shiny 0.4.0 now available

Shiny 0.4.0 simplifies the reactive API and suspends invisible outputs to reduce server load

Winston Chang

Shiny 0.3.0 released

Shiny 0.3.0 improves reactive scheduling efficiency and adds runGitHub() for running apps from GitHub

Winston Chang

ggplot2 0.9.3 and plyr 1.8 have been released!

ggplot2 0.9.3 fixes bugs and adds stat warnings; plyr 1.8 brings sequential summarise() and.paropts

Winston Chang