Shiny in Production

This workshop provides an introduction to coding a web application using Shiny for Python. It is aimed at providing R users, who are already familiar with Shiny, the tools and understanding to write similar apps using Python. In addition to using Shiny for Python yourself, this will also give you the capability to discuss Shiny with your Python colleagues, for example when you work in a bi-lingual data science team.

In this half-day workshop you will learn the basic building blocks of a Shiny application which will let you create both quick, simple applications and elaborate mission-critical ones. In particular this workshop covers:

• The basics of building a Shiny for Python app
• When to use reactive calculations and reactive effects
• How modules can help you develop reusable components

• Build a Shiny app in Python

• Theming and deploying your application
• Articulate how Shiny differs from other frameworks
• Utilise best practices to make sure your app is robust and scalable

The diverse range of devices used for modern web browsing presents challenges when designing an application that works well for all users. Enter responsive design: the practice of building fluid web pages that “work” on huge 4k and 5k monitors, tiny smartphones and all things in between. This course will look at responsive design principles and best practices for Shiny developers, covering page layout, easy-to-add widgets and some simple CSS tricks for when built-in solutions don’t quite cut it.

By the end of the workshop, participants will…

• know what responsive web design is
• know how to use flexible grids to adjust page layout for mobile, tablet and desktop
• be able to use HTML5 elements and Shiny Widgets to use limited space efficiently and effectively
• know how to add CSS and JavaScript snippets to an app for finer customisations
• understand how to test Shiny apps on various screen sizes from desktop to mobile

Automated testing plays a vital role in any production-grade software project. But what benefit does well-tested code bring to a project, and how do you write a good test suite for your shiny application? In this workshop, we demonstrate how to document the behaviour of an application using browser-driven end-to-end tests and show that lower-level, module- or function-focussed, tests make development a happier and more predictable experience. The tools used here (shinytest2, testServer) all build upon the testthat package.

By the end of the workshop, participants will…

• appreciate why testing software is important
• be familiar with those tools that make software testing easy in R
• know the different levels at which a Shiny application can be tested
• know when, and when not, to use snapshot testing
• know how to automatically generate end-to-end tests for {shinytest2}