Issue with dynamic messages when creating a dashboard using shiny R

Question

I'm trying to have a dynamic message functionality on my dashboard which I'm creating using shiny R. This is my code:

server.R

library(shiny)
library(shinydashboard)

shinyServer(function(input,output){
  
  output$`$histogram`<- renderPlot({
  hist(faithful$eruptions,breaks = input$bins)
      })
  output$msgOut <- renderMenu({
  msgs <- apply(read.csv("msg.csv"),1,function(row){
    messageItem(from = row[["from"]],message = row[["message"]])}
    ) 
  dropdownMenu("messages", .list = msgs)
  })

})

ui.R

library(shiny)
library(shinydashboard)

shinyUI(
  dashboardPage(
    dashboardHeader(title="Edureka",dropdownMenuOutput("msgOut")
                    # dropdownMenu(
                    #   type = "message",
                    #   messageItem(from = "Finance Update",message = "whats up niggas"),
                    #   messageItem(from = "Sales Update",message = "Meeting at 6PM on Monday", time = "15:00",icon = icon("handshake-o"))
                    # )
                   ),
    dashboardSidebar(
      sliderInput("bins","number of breaks",1,100,50),
      sidebarMenu(
      menuItem("Monthly Sales",tabName = "dashboard"),
    menuSubItem("DevOps",tabName = "DevOps"),
    menuSubItem("Blockchain",tabName = "Blockchain"),
    menuSubItem("AWS",tabName = "AWS"),
    menuItem("Finance Dashboard",tabName = "Finance"),
    menuSubItem("Revenue Generated",tabName = "Revenue"),
    menuSubItem("Company Expenditure",tabName = "Expenditure"))
    ),
    dashboardBody(
      tabItems(
        tabItem(tabName = "dashboard",
        fluidRow(
          box(plotOutput("$histogram")))
        ),
        tabItem(tabName = "DevOps",h1("DevOps courses sold")
         ),
        tabItem(tabName = "Blockchain",h1("Blockchain courses sold")
                ),
        tabItem(tabName = "AWS",h1("AWS Courses sold")),
        tabItem(tabName = "Finance",h1("Financial Growth")),
        tabItem(tabName = "Revenue", h1("Revenue Generated")),
        tabItem(tabName = "Expenditure",h1("Company Expenditures"))
  )
    )
  )
)

I get this error when i run the app

Answer 1

I had a wrong argument to one of my function, correcting it started working. Thanks @Maverick.

Answer 2

Hey @Ali, seems like the file you're trying to open is the wrong one. Check the file name and the extension. Also try adding the entire path of the file. Let me what output you get after this.

Comments

I get an error saying:

"Error in sourceUTF8(serverR, envir = new.env(parent = globalenv())) :
error sourcing /path/"

---

Have a look at this:

https://www.edureka.co/community/31698/saying-sourcing-appdata-local-rtmp8itrbm-file54f8276958b3?show=31698#q31698

---

Still no luck, I'm getting another error now:

Error: '\U' used without hex digits in character string starting ""C:\U"

---

In your path add an extra '\' after every slash.

https://www.edureka.co/community/31410/error-without-digits-character-string-starting-trying-file

---

I tried this as well. i get this as the output:

error saying:

Expected an object with class 'shiny.tag'

---

This error occurs when the arguments passed are incorrect. check the arguments.

---

Yes @Maverick, I had screwed up with arguments with one of the function. Thanks, its working now.

Answer 3

Hey @Ali, Start a new session and copy the same code there. I'm not very sure but that has worked for me.