Why does shiny's default app cause javascript errors and warnings?

0

When running the default shiny app of RStudion (Old Faithful Geyser Data) in Firefox, there are several JavaScript errors and warnings shown in the console, while the app itself works fine. Why do they occur?

The same errors also occur when accessing Shiny-apps online, for example https://shiny.rstudio.com/gallery/lego-set.html

Background: I have problems with a slow App, and want to make sure that everything is fine with the setup. As there are JavaScript errors and warnings shown in the console in all applications I checked(while the apps themselves run fine), I want to be sure that these are not causing problems in performance.

This is the Output of the Firefox Console:

undefined pageModifier.js:585:9
Mutations-Ereignisse sollten nicht mehr verwendet werden. Verwenden Sie MutationObserver stattdessen. pageModifier.js:81:20
[Exception... "Favicon at "http://127.0.0.1:4399/favicon.ico" failed to load: Not Found."  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: resource:///modules/FaviconLoader.jsm :: onStopRequest :: line 186"  data: no]
unreachable code after return statement ExtensionContent.jsm:513:8
Unchecked lastError value: Error: Script '<anonymous code>' result is non-structured-clonable data background.js:273
unreachable code after return statement ExtensionContent.jsm:517:8
Unchecked lastError value: Error: Script '<anonymous code>' result is non-structured-clonable data background.js:273
unreachable code after return statement ExtensionContent.jsm:515:8
Unchecked lastError value: Error: Script '<anonymous code>' result is non-structured-clonable data background.js:273
unreachable code after return statement ExtensionContent.jsm:513:8
Unchecked lastError value: Error: Script '<anonymous code>' result is non-structured-clonable data background.js:273
unreachable code after return statement ExtensionContent.jsm:517:8
Unchecked lastError value: Error: Script '<anonymous code>' result is non-structured-clonable data background.js:273
unreachable code after return statement ExtensionContent.jsm:515:8
Unchecked lastError value: Error: Script '<anonymous code>' result is non-structured-clonable data background.js:273

I use Firefox 65 on Windows 7, R version 3.3.3 (2017-03-06), shiny 1.2.0 and RStudio Version 1.0.136.

This is the app (unchanged New Shiny App):

#
# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(shiny)

# Define UI for application that draws a histogram
ui <- fluidPage(

   # Application title
   titlePanel("Old Faithful Geyser Data"),

   # Sidebar with a slider input for number of bins 
   sidebarLayout(
      sidebarPanel(
         sliderInput("bins",
                     "Number of bins:",
                     min = 1,
                     max = 50,
                     value = 30)
      ),

      # Show a plot of the generated distribution
      mainPanel(
         plotOutput("distPlot")
      )
   )
)

# Define server logic required to draw a histogram
server <- function(input, output) {

   output$distPlot <- renderPlot({
      # generate bins based on input$bins from ui.R
      x    <- faithful[, 2] 
      bins <- seq(min(x), max(x), length.out = input$bins + 1)

      # draw the histogram with the specified number of bins
      hist(x, breaks = bins, col = 'darkgray', border = 'white')
   })
}

# Run the application 
shinyApp(ui = ui, server = server)
javascript
r
shiny
asked on Stack Overflow Feb 1, 2019 by Julian • edited Feb 1, 2019 by Julian

1 Answer

0

Errors occured because of Firefox-Addon "Citavi Picker, Version 2017.12.21". Disabling this Addon, the Errors disappeared.

Let's see what their support says...

answered on Stack Overflow Feb 7, 2019 by Julian • edited Feb 7, 2019 by Julian

User contributions licensed under CC BY-SA 3.0