Скачать или смотреть Barret Schloerke || {reactlog} Rundown || RStudio

00:00 Introduction to Reactlog
00:44 Viewing Reactlog using an Old Faithful Shiny app
02:07 The Reactlog interface
04:31 Walking through a reactive graph with Reactlog
05:14 Downstream dependency invalidation in Shiny
06:43 How Shiny "grabs" data
09:41 How the Reactlog timeline works
10:46 Switching between idle states in Reactlog
11:58 Reactlog interactivity - clicking a single item
13:21 Reactlog with the Pythagoras Theorem app
15:45 Adding a UI and server value to add Reactlog to your Shiny app
18:05 Walking through the reactive graph using the Pythagorean Theorem app
21:07 Append-only behavior of Reactlog
21:18 Marking a time point in Reactlog
23:17 Using Reactlog to debug reactivity
26:55 Resetting our app and testing logic changes
28:01 Reactlog with a large Shiny app, CRANwhales
34:10 Freezing reactive values
36:19 Calculating click count in a Shiny app
37:10 Click the button, render the plot is bad - see why

Shiny is an R package from RStudio that makes it incredibly easy to build interactive web applications with R. Behind the scenes, Shiny builds a reactive graph that can quickly become intertwined and difficult to debug. reactlog provides a visual insight into that black box of Shiny reactivity.

After logging the reactive interactions of a Shiny application, reactlog constructs a directed dependency graph of the Shiny’s reactive state at any time point in the record. The reactlog dependency graph provides users with the ability to visually see if reactive elements are:

Not utilized (never retrieved)
Over utilized (called independently many times)
Interacting with unexpected elements
Invalidating all expected dependencies
Freezing (and thawing), preventing triggering of future reactivity

There are many subtle features hidden throughout reactlog. Here is a short list quickly describing what is possible within reactlog:

Display the reactivity dependency graph of your Shiny applications
Navigate throughout your reactive history to replay element interactions
Highlight reactive family trees
Filter on reactive family trees
Search for reactive elements

You can read more about reactlog here: https://rstudio.github.io/reactlog/ar...
And 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: Barret Schloerke (@schloerke)
Design & editing: Jesse Mostipak (@kierisi)