Provides an interactive browser-based tool for visualizing reactive dependencies and execution in your application.
reactlog_render(log, session_token = NULL, time = TRUE) reactlog_show(log, time = TRUE, ...)
Log produced by shiny to be processed
token to be used to subset which session is displayed. Defaults to all sessions.
A boolean that specifies whether or not to display the time that each reactive takes to calculate a result.
Future parameter expansion. Currently ignored
To use the reactive log visualizer, start with a fresh R session and
run the command
reactlog_enable(); then launch your
application in the usual way (e.g. using
any time you can hit
(or for Mac users,
) in your web browser to launch the reactive log visualization.
The reactive log visualization only includes reactive activity up until the time the report was loaded. If you want to see more recent activity, refresh the browser.
Note that Shiny does not distinguish between reactive dependencies that "belong" to one Shiny user session versus another, so the visualization will include all reactive activity that has taken place in the process, not just for a particular application or session.
As an alternative to pressing
--for example, if you
are using reactives outside of the context of a Shiny
application--you can run the
shiny::reactlogShow() function, which will
generate the reactive log visualization as a static HTML file and
launch it in your default browser. In this case, refreshing your
browser will not load new activity into the report; you will need to
For security and performance reasons, do not enable the reactlog in production environments. When the option is enabled, it's possible for any user of your app to see at least some of the source code of your reactive expressions and observers.