ShinyProxy + Shiny : App Recovery

ShinyProxy
#1

Hi,

I tried the app recovery new feature of ShinyProxy 2.6.0, it is amazing THANK YOU :slight_smile:

In same cases isn’t working correctly for me, specially when I use reactiveVal in my application, so if the application is recovered [after ShinyProxy restarting], the reactiveVals are reinitialized automatically.

Do you have an idea how to keep the same reactiveVal (values) as updated whithin the session to recover ?
How to force shiny to not create new R process when the app get recovered ?

Regards
Ada

#2

I don’t think this is possible.

See this article:
https://shiny.rstudio.com/articles/reconnecting.html

1 Like
#3

Hi

How to force shiny to not create new R process when the app get recovered ?

This is indeed not possible, however, it is possible to write your app in such a way that after reconnecting you end up with the same data/values.

In link posted above, you can find this section:

For your application to work with this kind of reconnection, the state of the inputs must fully determine the state of the outputs. This kind of reconnection will not work for applications that store intermediate state on the server and require, for example, inputs to occur in a particular sequence in order to reach the desired output state. Here are some things that will cause problems for this type of reconnection:

  • The server function stores some values in a reactiveValues object, or in other variables that are not part of a standard reactive flow. An example: a variable that counts the number of times an actionButton is pressed.
  • The user uploads a file to a fileInput().
  • The application generates random values (with rnorm(), runif(), or similar).

If you follow these recommendations, the reconnecting mechanism should work.

Looking forward to your feedback!

1 Like