How do I resolve this R shiny server looping if condition issue?-CodePudding

Context: I am trying to make a shiny feature where the user can upload txt files and view the content of the files as a table. To account for the different types of delimiters I have placed radio buttons to act as delimiter options. The radio buttons will depend on the file type uploaded.

Issue: The user would not be able to change the delimiter options and display the respective table, because the server keeps checking the file type and changing the radio buttons and resetting the default button.

Attempted solutions:

Setup a radiobutton for the user to select the file type which changes the delimited buttons instead of using an if condition of file type to determine the delimiter radiobuttons. Solution is not user friendly since the program should be able to identify and modify the radiobuttons in accordance to the file type.
Setup a go button to perform the if conditions for file type instead of relying on the server looping. Couldn't implement it properly

Question: Can anyone suggest solutions that are user friendly? Is there a feature in R shiny that already solves this issue?

library(shinyWidgets)
library(DT)
library(shiny)
ui <- fluidPage(
  titlePanel(title=div(img(src="ODClogo.png", height = 50), "OutDeCo")),
  
  #navbarPage is top menu bar
  navbarPage("",

            #tabPanel is each tab in the navbarPage          
            # Assess DE tab
             tabPanel(
              title="Assess DE",
              dropdown(

                # title of sidepanel
                 tags$h3("Options"),

                 # inputs in the sidepanel
                fileInput("DEFile", "Choose DE File",
                  accept = c(
                   ".csv",
                   ".tsv",
                   ".txt"
                   )
                ),

                # button for selecting delimiter, default is nothing until file is selected and handled in server side
                radioButtons(inputId = 'sepButton', label = 'Delimiter Selector', choices = c(Default=''), selected = ''),

                # side panel characteristics
                style = "gradient", icon = icon("cog"),
                status = "primary", width = "300px",
                animate = animateOptions(
                enter = animations$fading_entrances$fadeInLeftBig,
                exit = animations$fading_exits$fadeOutLeftBig
                )
               ),
              
              navlistPanel(
                tabPanel(
                  title="Cluster Genes",
                  "Cluster genes Page",

                  # Navigation Bar for types of plots inside cluster
                  tabsetPanel(
                    tabPanel(
                      title="View file",
                      mainPanel(
                        uiOutput("UIDEContent") 
                      )
                      
                    ),
                    tabPanel(
                      title="Plot 2"
                    ),
                    tabPanel(
                      title="Plot 3"
                    )
                  ),
                ),
               ),
             )
  ),
)

Server

server <- function(input, output, session) {
  output$distPlot <- renderPlot({
    hist(rnorm(input$obs), col = 'darkgray', border = 'white')
  })
  # reactive converts the upload file into a reactive expression known as data
  data <- reactive({

  # DEFile from fileInput() function
  ServerDEFile <- input$DEFile

  # extensions tool for format validation
  extDEFile <- tools::file_ext(ServerDEFile$datapath)

  # file format checking
  req(ServerDEFile)
  validate(need(extDEFile == c("csv", "tsv", "txt"), "Please upload a csv, tsv or txt file."))

  # convert data into file format
  if(is.null(extDEFile)){return()} 

  if (extDEFile == "txt") {
    choice <-c(Comma=",", Semicolon=";", Tab="\t", Space=" ")
    updateRadioButtons(session, "sepButton",
                      label = paste("Delimiters for", extDEFile, "file"),
                      choices = choice,
                      )
  }
  else if (extDEFile == "tsv") {
    choice <- (Tab="\t")
    updateRadioButtons(session, "sepButton",
              label = paste("Delimiter: Tab"),
              choices = choice
              )
  }
  else {
    choice <- (Comma=",")
    updateRadioButtons(session, "sepButton",
              label = paste("Delimiter: Comma"),
              choices = choice
              )
  }

  read.table(file=ServerDEFile$datapath, sep=input$sepButton)
  })

  # creates reactive table called DEFileContent
  output$DEFileContent <- renderTable({
  if(is.null(data())){return ()}
  data()
  })

  # handles rendering of reactive object on tb on ui
  output$UIDEContent <- renderUI({
    tableOutput("DEFileContent")
  })
}

CodePudding user response：

Use reactive object just to create a data frame, and use an observer to update radio button. Try this

library(shinyWidgets)
library(DT)
library(shiny)
ui <- fluidPage(
  titlePanel(title=div(img(src="ODClogo.png", height = 50), "OutDeCo")),

  #navbarPage is top menu bar
  navbarPage("",

             #tabPanel is each tab in the navbarPage
             # Assess DE tab
             tabPanel(
               title="Assess DE",
               dropdown(

                 # title of sidepanel
                 tags$h3("Options"),

                 # inputs in the sidepanel
                 fileInput("DEFile", "Choose DE File",
                           accept = c(
                             ".csv",
                             ".tsv",
                             ".txt"
                           )
                 ),

                 # button for selecting delimiter, default is nothing until file is selected and handled in server side
                 radioButtons(inputId = 'sepButton', label = 'Delimiter Selector', choices = c(Default=''), selected = ''),

                 # side panel characteristics
                 style = "gradient", icon = icon("cog"),
                 status = "primary", width = "300px",
                 animate = animateOptions(
                   enter = animations$fading_entrances$fadeInLeftBig,
                   exit = animations$fading_exits$fadeOutLeftBig
                 )
               ),

               navlistPanel(
                 tabPanel(
                   title="Cluster Genes",
                   "Cluster genes Page",

                   # Navigation Bar for types of plots inside cluster
                   tabsetPanel(
                     tabPanel(
                       title="View file",
                       mainPanel(
                         uiOutput("UIDEContent")
                       )

                     ),
                     tabPanel(
                       title="Plot 2"
                     ),
                     tabPanel(
                       title="Plot 3"
                     )
                   ),
                 ),
               ),
             )
  ),
)

server <- function(input, output, session) {
  output$distPlot <- renderPlot({
    hist(rnorm(input$obs), col = 'darkgray', border = 'white')
  })
  
  observe({
    # DEFile from fileInput() function
    ServerDEFile <- req(input$DEFile)
    
    # extensions tool for format validation
    extDEFile <- tools::file_ext(ServerDEFile$datapath)
    if(is.null(input$DEFile)){return()
    }else{
      if (extDEFile == "txt") {
        label = paste("Delimiters for", extDEFile, "file")
        choice <-c(Comma=",", Semicolon=";", Tab="\t", Space=" ")
      }else if (extDEFile == "tsv") {
        label = paste("Delimiter: Tab")
        choice <- (Tab="\t")
      }else {
        label = paste("Delimiter: Comma")
        choice <- (Comma=",")
      }
      updateRadioButtons(session, "sepButton", label = label, choices = choice)
    }
  })
  
  # reactive converts the upload file into a reactive expression known as data
  data <- reactive({

    # DEFile from fileInput() function
    ServerDEFile <- input$DEFile

    # extensions tool for format validation
    extDEFile <- tools::file_ext(ServerDEFile$datapath)

    # file format checking
    req(ServerDEFile)
    validate(need(extDEFile == c("csv", "tsv", "txt"), "Please upload a csv, tsv or txt file."))

    # convert data into file format
    if(is.null(extDEFile)){return()}

    read.table(file=ServerDEFile$datapath, sep=input$sepButton)
  })

  # creates reactive table called DEFileContent
  output$DEFileContent <- renderTable({
    if(is.null(data())){return ()}
    data()
  })

  # handles rendering of reactive object on tb on ui
  output$UIDEContent <- renderUI({
    tableOutput("DEFileContent")
  })
}

shinyApp(ui = ui, server = server)