Problem with the SHINY application

Hi, my application won't work, unfortunately I can't find a reason. Someone will help?

#########file server.R

# shiny server side code for each call
server<-(function(input, output, session){

  #update group and
  #variables based on the data
  observe({
    #browser()
    if(!exists(input$dataset)) return() #make sure upload exists
    var.opts<-colnames(get(input$dataset))
    updateSelectInput(session, "variable", choices = var.opts)
    updateSelectInput(session, "group", choices = var.opts)
  })

  output$caption<-renderText({
    switch(input$plot.type,
           "boxplot" 	= 	"Boxplot",
           "histogram" =	"Histogram")
  })


  output$plot <- renderUI({
    plotOutput("p")
  })

  #get data object
  get_data<-reactive({

    if(!exists(input$dataset)) return() # if no upload

    check<-function(x){is.null(x) || x==""}
    if(check(input$dataset)) return()

    obj<-list(data=get(input$dataset),
              variable=input$variable,
              group=input$group
    )

    #require all to be set to proceed
    if(any(sapply(obj,check))) return()
    #make sure choices had a chance to update
    check<-function(obj){
      !all(c(obj$variable,obj$group) %in% colnames(obj$data))
    }

    if(check(obj)) return()


    obj

  })

  #plotting function using ggplot2
  output$p <- renderPlot({

    plot.obj<-get_data()

    #conditions for plotting
    if(is.null(plot.obj)) return()

    #make sure variable and group have loaded
    if(plot.obj$variable == "" | plot.obj$group =="") return()

    #plot types
    plot.type<-switch(input$plot.type,
                      "boxplot" 	= geom_boxplot(),
                      "histogram" =	geom_histogram(alpha=0.5,position="identity"),
                      "density" 	=	geom_density(alpha=.75),
                      "bar" 		=	geom_bar(position="dodge")
    )


    if(input$plot.type=="boxplot")	{		#control for 1D or 2D graphs
      p<-ggplot(plot.obj$data,
                aes_string(
                  x 		= plot.obj$group,
                  y 		= plot.obj$variable,
                  fill 	= plot.obj$group # let type determine plotting
                )
      ) + plot.type

      if(input$show.points==TRUE)
      {
        p<-p+ geom_point(color='black',alpha=0.5, position = 'jitter')
      }

    } else {

      p<-ggplot(plot.obj$data,
                aes_string(
                  x 		= plot.obj$variable,
                  fill 	= plot.obj$group,
                  group 	= plot.obj$group
                  #color 	= as.factor(plot.obj$group)
                )
      ) + plot.type
    }

    p<-p+labs(
      fill 	= input$group,
      x 		= "",
      y 		= input$variable
    )  +
      .theme
    print(p)
  })

  # set uploaded file
  upload_data<-reactive({

    inFile <- input$file1

    if (is.null(inFile))
      return(NULL)

    #could also store in a reactiveValues
    read.csv(inFile$datapath,
             header = input$header,
             sep = input$sep)
  })

  observeEvent(input$file1,{
    inFile<<-upload_data()
  })


})


# Create Shiny app ----
shinyApp(ui, server)

########### File UI.R

#initialize
library(shiny)
library(ggplot2)
library(purrr)
library(dplyr)

#plotting theme for ggplot2
.theme<- theme(
  axis.line = element_line(colour = 'gray', size = .75),
  panel.background = element_blank(),
  plot.background = element_blank()
)


# UI for app
ui<-(pageWithSidebar(
  # title
  headerPanel("Select Options"),
  
  #input
  sidebarPanel
  (
    # Input: Select a file ----
    
    fileInput("file1", "Wybierz plik CSV",
              accept = c("text/csv",
                         "text/comma-separated-values,text/plain",
                         ".csv")),
    # Input: Checkbox if file has header ----
    checkboxInput("header", "Naglowek", TRUE),
    
    # Input: Select separator ----
    radioButtons("sep", "Separator",
                 choices = c(Średnik = ";",
                             Przecinek = ",",
                             Tabulator = "\t"),
                 selected = ";"),
    # Horizontal line ----
    tags$hr(),
    
    
    # Input: Select what to display
    selectInput("dataset","Dana:",
                choices =list(Plik = "inFile", iris = "iris"), selected=NULL),
    selectInput("variable","Zmienna:", choices = NULL),
    selectInput("group","Grupa:", choices = NULL),
    selectInput("plot.type","Typ:",
                list(boxplot = "boxplot", histogram = "histogram")
    ),
    checkboxInput("show.points", "Poka┼╝ punkty", TRUE)
  ),
  
  # output
  mainPanel(
    h3(textOutput("caption")),
    #h3(htmlOutput("caption")),
    uiOutput("plot") # depends on input
  )
))

ERROR

> runApp()

Listening on http://127.0.0.1:3819
Ostrze┼╝enie: Error in force: nie znaleziono obiektu 'ui'
  54: force
  53: uiHttpHandler
  52: shinyApp
Error in force(ui) : nie znaleziono obiektu 'ui'

Thanks for any Help

When you work with two files for your shiny app, you shouldn't include this line.
You are getting that error message because that command is looking for the ui function inside your server.R file and it doesn't exist on that context.

3 Likes

Hello Again, I can't deal with Error right now.


Object '.theme' not found

This is the part it is causing the issue, either you are using the wrong syntax or you have forgotten to define an object called .theme (BTW this would be a non-syntactic name).

Can you explain what are you trying to accomplish with this part of the code?

1 Like
ERROR: Don't know how to add theme to a plot

I'm trying to add a sequence output to the theme.'

Unless you are right there should be a theme not .themed
but for corrector I have Error:

p+labs( fill = input$group, x = "", y = input$variable ) +theme(
  axis.line = element_line(colour = 'gray', size = .75),
  panel.background = element_blank(),
  plot.background = element_blank()
)
1 Like