Developing Data Products Slide Deck

Using progress inidcator in Shiny

jp4711

A Shiny Application with Progress Indicator

Demonstrates the use of progress indicator during long running task
Demonstrates to interactivly save data sets or results
Downloads data "pml" from internet if not on machine
Loads data set into memory
Shows progress indicator when loading 'pml' data set into memory
Show summary info of loaded data set
Shows first n rows of data set

How to create Shiny App With Progress Indicator

create ui.R
create server.R
load library ShinyIncubator

Progress Indicator within Shiny

in ui.R

library(shinyIncubator)

# and inside the layout

  progressInit(),

This will initiate progress indicator

Progress Indicator Server Code

Inside server.R code:

call withProgress to create dialog with progress bar
update the progress bar periodicially

Sample Code

library(shinyIncubator)

# and inside the server code

withProgress(session, min = 0, max = 10, {
      setProgress(message = "Training the model:")

Server Side Example Code

an long running operation

  anExpensiveOperation <- function() {
    #
    # sdet min/max and setProgress(value=x) for progress bar
    withProgress(session, min = 0, max = 10, {
      setProgress(message = "Training the model:")
      for (i in 1:10) {
        setProgress(value = i)
        # wait more for background process to complete
        if (!hasMyTaskCompleted())
            Sys.sleep(1.0)
      }
    })
  }

Conclusion

With Shiny and ShinyIncubator long running processes can be created and progress shown during execution time

ShinyIncubator is under development and new features are added.