Shiny无法从上传的csv中基于selectInput读取列 问题：准备工作：库和示例数据 UI 服务器保险丝警告：

如何解决Shiny无法从上传的csv中基于selectInput读取列 问题：准备工作：库和示例数据 UI 服务器保险丝警告：

问题：

我正在尝试构建一个闪亮的应用程序，该应用程序根据用户上传的csv中的用户指定列来绘制n-gram的频率。此外，还添加了一个功能，可以根据用户指定的日期列绘制随时间变化的兴趣点。

该应用在本地正常运行，显示警告，但发布后无法正常工作。请参见以下示例，以获取可重复的示例。

准备工作：库和示例数据

p = [[0,1,1],[0,2,3,3],4]]
array = [0.6,0.5,0.9]
for i in range(len(p)):
    if p[i][0] == 0:
        p[i][0] = array[i]  # use random() if you want to replace with a random number
print(p)

UI

# Load R packages
library(shiny)
library(tidyverse)
library(shinythemes)
library(lubridate)
library(tidytext)
library(textdata)

# Creating a example csv file for upload
Sample_csv <- 
  data.frame(text = janeaustenr::emma,id = 1:length(janeaustenr::emma),date = sample(seq(as.Date('1900/01/01'),as.Date('1920/01/01'),by="day"),replace = T,length(janeaustenr::emma)))
write.csv(Sample_csv,"Sample_csv.csv",row.names = F)

服务器

ui <- fluidPage(theme = shinytheme("united"),titlePanel("Text glancer"),sidebarLayout(
                  sidebarPanel(
                    # Input: Select a file ----
                    fileInput("csv_file","Feed csv here",multiple = FALSE,accept = c(".csv")),#Conditional panel 
                    conditionalPanel(
                      # use a server side condition
                      condition = "output$fileUploaded",# Input: Select  ----
                      uIoUtput("text_select"),# Input: Select  ----
                      uIoUtput("date_select"),# Input: Simple integer interval ----
                      sliderInput("top_frequency","Top n ngrams to be plotted:",min = 5,max = 20,value = 10),# Input: Select  ----
                      selectInput("ngrams","Ngrams of your choice:",c("Single word" = 1,"Bigram" = 2,"Trigram" = 3)
                      )
                    ),# Submit bottom
                    submitButton("Update View",icon("refresh"))
                  ),# sidebarPanel
                  mainPanel(
                    tabsetPanel(
                      tabPanel(h2("Most frequenlty used n-grams"),plotOutput("frequency_plot",height = 900,width = 1200)),tabPanel(h2("Sentiment of the months"),plotOutput("sentiment_plot",width = 1200))
                    )
                  )
                ) 
)

保险丝

server <- function(input,output,session) {
  
  # create reactive version of the dataset (a data.frame object)
  LOAD_DATA <- reactive({
    infile <- input$csv_file
    if (is.null(infile)) 
    {return(NULL)}
    {read_csv(infile$datapath)}
  })
  
  
  # inform conditionalPanel wheter dropdowns sohould be hidden
  output$fileUploaded <- reactive({
    return(!is.null(LOAD_DATA()))
  })
  outputoptions(output,'fileUploaded',suspendWhenHidden=FALSE)
  
  ## update 'column' selectors
  output$text_select <- renderUI({
    if(is.null(LOAD_DATA()))
    {return(NULL)}
    else
      selectInput("text_col","Select the text column:",colnames(LOAD_DATA()))
  })
  
  output$date_select <- renderUI({
    if(is.null(LOAD_DATA()))
    {return(NULL)}
    else
      selectInput("date_col","Select the date column (ymd):",colnames(LOAD_DATA())) 
  })
  
  # Create reactive parameters
  TOP_FREQUENCY <- reactive({
    input$top_frequency
  })
  N_GRAMS <- reactive({
    as.numeric(as.character(input$ngrams))
  })

  # Output frequency of ngrams
  output$frequency_plot <- renderPlot( {
    
    if(is.null(LOAD_DATA()))
    {return(NULL)}
    
    else{
      
      WORK_DATA <-  LOAD_DATA()[,c(input$text_col,input$date_col)]
      names(WORK_DATA) <- c("TEXTS","DATES")
      
      CSV_DOC_N_Grams <-
        WORK_DATA %>%
        # LOAD_DATA() %>%
        # select(TEXTS = TEXT_COL(),DATES = DATE_COL()) %>%
        mutate(TEXTS = gsub("http.*"," ",TEXTS)) %>%
        # mutate(text = gsub("\\@.* |\\@.* .|\\@.*,",text)) %>%
        unnest_tokens(words,TEXTS,token = "ngrams",n = N_GRAMS()) %>%
        select(words) %>%
        filter(str_detect(words,"[a-zA-Z]")) %>%
        separate(words,c("word1","word2","word3"),sep = " ",remove = F) %>%
        filter(! word1 %in% stop_words$word &
                 ! word2 %in% stop_words$word&
                 ! word3 %in% stop_words$word)
      
      #Counting ngrams
      CSV_DOC_N_Gramss_Count <-
        CSV_DOC_N_Grams %>%
        count(words,sort=T) %>%
        select(N_Gram_Text = words,N_Gram_Count = n)
      
      #Plotting ngram frequency
      CSV_DOC_N_Gramss_Count_freq <-
        CSV_DOC_N_Gramss_Count %>%
        mutate(N_Gram_Text = fct_reorder(N_Gram_Text,N_Gram_Count)) %>%
        top_n(TOP_FREQUENCY(),N_Gram_Count) %>%                          
        ggplot(aes(x = N_Gram_Text,y = N_Gram_Count,fill = N_Gram_Count)) +
        geom_col()+
        coord_flip() +
        scale_fill_gradient2()+
        labs(title = paste0("Top ",TOP_FREQUENCY()," ngrams used in csv doc"),x = "ngrams",y = "frequency") +
        theme_bw()+
        theme(legend.position = "none",axis.text.x = element_text(face='bold',size=12),axis.text.y = element_text(face='bold',axis.title.x = element_text(face='bold',size=18),axis.title.y = element_blank())
      print(CSV_DOC_N_Gramss_Count_freq)
    }
  })
  
  
  output$sentiment_plot <- renderPlot( {
    
    if(is.null(LOAD_DATA())){return(NULL)}
    
    else{
      
      WORK_DATA <-  LOAD_DATA()[,"DATES")
      
      tk_afinn <-
        WORK_DATA %>%
        mutate(TEXTS = gsub("http.*",TEXTS)) %>%
        unnest_tokens(word,TEXTS) %>%
        filter(! word %in% stop_words$word) %>%
        filter(str_detect(word,"[a-zA-Z]")) %>%
        filter(! DATES %in% NA) %>%
        inner_join(get_sentiments("afinn")) %>%
        mutate(YEAR_Month = ymd(paste(year(DATES),month(DATES),"1",sep="-"))) %>%
        group_by(index = YEAR_Month) %>%
        summarise(sentiment = sum(value))
      
      tk_afinn_plot <-
        tk_afinn  %>%
        ggplot(aes(x = index,y = sentiment)) +
        geom_line()+
        labs(x = "date (year-month)",y = "sentiment of the month") +
        theme_bw()+
        theme(legend.position = "none",axis.title.y = element_blank())
      print(tk_afinn_plot)
    }
  })
} 

警告：

加载csv文件后，本地应用会报告： “ shinyApp(ui = ui,server = server) 输入mutate()有问题。 找不到对象“ TEXTS” 输入TEXTS是TEXTS。”

指定文本列和日期列后，两个选项卡均显示图。但是，将其发布到Shinyapp.io之后，它会报告错误并且无法运行。

有人可以帮助解决这个问题吗？我已经咨询了其他线程，包括this> https://stackoverflow.com/questions/47248534/dynamically-list-choices-for-selectinput-from-a-user-selected-column，但仍然没有运气。

任何见识将不胜感激！