Why Shiny modules will (really) make future you smile!

# Why Shiny modules will (really) make future you smile!

Eric Nantz

South Coast MA UseR! Group | 5 November 2020

Slides available at [bit.ly/shinymod2020](https://bit.ly/shinymod2020)

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# Find me at ...

[ @rpodcast](https://github.com/rpodcast)

[ @theRcast](https://twitter.com/theRcast)

[ Shiny Developer Series](https://shinydevseries.com)

[ R Podcast](https://r-podcast.org)

[ R Weekly Highlights](https://rweekly.fireside.fm/)

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# Why should you care?

* Shiny apps often become popular **quickly**
]

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# Why should you care?

* Shiny apps often become popular **quickly**
* Repeating yourself gets old even **more quickly**!
]

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# Why should you care?

* Shiny apps often become popular **quickly**
* Repeating yourself gets old even **more quickly**!
* Organizes app into *distinct* and *composable* pieces
]

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# Modules sound hard ...

The technical benefits of modules are not exactly intuitive to a new Shiny developer:

- A smaller version of a Shiny app
- Avoid namespace collisions when using same widget across different parts of your app
- Always composed of 2 components: UI and Server

### Do you have to be an expert Shiny Developer to use modules?

![](https://media.giphy.com/media/3o6wrASxYzLbE9JWE0/giphy.gif)

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# Creating a Module

```r
snippet shinymod
	${1:name}_UI <- function(id) {
	 ns <- NS(id)
	 tagList(
		${0}
	 )
	}
	
	${1:name}_mod <- function(input, output, session) {
	 
	}
```
]

```r
golem::add_module("plot")
```

]

```r
#' plot UI Function
#'
#' @description A shiny Module.
#'
#' @param id,input,output,session Internal parameters for {shiny}.
#'
#' @noRd 
#'
#' @importFrom shiny NS tagList 
mod_plot_ui <- function(id){
 ns <- NS(id)
 tagList(
 
 )
}
```

]

```r
#' plot Server Function
#'
#' @noRd 
mod_plot_server <- function(input, output, session){
 ns <- session$ns
 
}
```
]

```r
## To be copied in the UI
# mod_plot_ui("plot_ui_1")
    
## To be copied in the server
# callModule(mod_plot_server, "plot_ui_1")
```

]
]

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# Demo Time!

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<blockquote class="twitter-tweet tw-align-center">It was long 🕗 coming ... here&#39;s my 1st-ever <a href="https://twitter.com/hashtag/TidyTuesday?src=hash&amp;ref_src=twsrc%5Etfw">#TidyTuesday</a> post! 🦕 Meet {shinysaurus}, a <a href="https://twitter.com/hashtag/rstats?src=hash&amp;ref_src=twsrc%5Etfw">#rstats</a> <a href="https://twitter.com/hashtag/shiny?src=hash&amp;ref_src=twsrc%5Etfw">#shiny</a> app exploring the datasaurus dozen! 📹 I joined <a href="https://twitter.com/ellis_hughes?ref_src=twsrc%5Etfw">@ellis_hughes</a> &amp; <a href="https://twitter.com/OSPpatrick?ref_src=twsrc%5Etfw">@OSPpatrick</a> in <a href="https://twitter.com/tidy_explained?ref_src=twsrc%5Etfw">@tidy_explained</a> TidyX ep32! <a href="https://t.co/7ADOHex3rg">https://t.co/7ADOHex3rg</a> 📊 app: <a href="https://t.co/WOWfrQXEj6">https://t.co/WOWfrQXEj6</a> demo 👇 <a href="https://t.co/ksbs8KVHyf">pic.twitter.com/ksbs8KVHyf</a>&mdash; The R-Podcast (Eric) (@theRcast) <a href="https://twitter.com/theRcast/status/1317920405387157505?ref_src=twsrc%5Etfw">October 18, 2020</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

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# Levelling Up

- [A beginner's guide to Shiny modules by Emily Riederer](https://emilyriederer.netlify.app/post/shiny-modules)
- [`shinySaurus` application](https://github.com/rpodcast/shinysaurus)
- Effective use of Shiny Modules talk from `rstudio::conf(2019)`: [repo](https://github.com/rpodcast/rsconf-2019), [slides](https://bit.ly/modules2019), [recording](https://rstudio.com/resources/rstudioconf-2019/effective-use-of-shiny-modules-in-application-development/)
- [Using {shiny} Modules](https://engineering-shiny.org/structure.html#using-shiny-modules) chapter from [Engineering Production-Grade Shiny Apps](https://engineering-shiny.org/) 
- [Shiny Modules](https://mastering-shiny.org/scaling-modules.html) chapter from [Mastering Shiny](https://mastering-shiny.org/index.html)
- [Communication between modules and its whims](https://rtask.thinkr.fr/blog/communication-between-modules-and-its-whims/)
- [Communication between modules article on Shiny dev center](https://shiny.rstudio.com/articles/communicate-bet-modules.html)
- [Super solutions for Shiny Apps #1: Using Session Data](https://appsilon.com/super-solutions-for-shiny-architecture-1-of-5-using-session-data/)
- Shiny Developer Series: [shinydevseries.com](https://shinydevseries.com)