R twitterwidget包-更新闪亮输入时未清除tweet

Question

每次我对renderTwitterwidget()的输入发生变化时，都会在闪亮的UI上的原始tweet下面打印一条新的tweet。是否可以在每次将新的twitterwidget对象传递给renderTwitterwidget时清除旧的tweet并打印新的tweet

问题的示例：https://media.giphy.com/media/BQUewH12DzhxX2bjMP/giphy.gif?cid=790b7611692336f45990123a77213a1975b8338b7e69b6e1&rid=giphy.gif&ct=g

代码没有使用RStudio查看器正确地呈现内容，所以请使用浏览器中的应用程序来检查结果。

这是这个闪亮的应用程序的代码：

# Libraries ---------------------------------------------------------------

library(shiny)
library(twitterwidget)
library(tidyverse)
library(rtweet)

# UI ----------------------------------------------------------------------

ui <- fluidPage(
  # Input functions
  textInput(inputId = 'search_term',
            label = 'Search tweets from the last 6-9 days:',
            #value = 'covid',
            placeholder = '#covid-19',
            width = '90%'
  ),
  actionButton(inputId = 'submit_button',
               label = 'Submit'
  ),
  
  # Output functions 
  twitterwidgetOutput('twitter', width = "100%", height = "400px")
)

# Server ------------------------------------------------------------------

server <- function(input, output) {
  
  # Get data 
  tweet_id <- eventReactive(input$submit_button, {search_tweets(q = input$search_term, n = 1, lang = 'en') %>% pull(status_id)})
 
  # Twitter widget
  output$twitter <- renderTwitterwidget(twitterwidget(tweet_id()))
  
}

shinyApp(ui, server)

没有twitter帐户的人的代码：

# Libraries ---------------------------------------------------------------

library(shiny)
library(twitterwidget)
library(tidyverse)


# Vector of tweet status_id's ---------------------------------------------

v_ids <- c("1434550715905724416", "1434404394133594112", "1434270392533889039", "1432293982541946884", "1432396306698354688",
           "1434187565633003526", "1433095963338551297", "1432339458309955585", "1431909314600574977","1432064144040202241",
           "1434268168231477248", "1431912031100227589", "1434188285103022086", "1432066801588920325", "1434184994579230720",
           "1434100772069908485", "1433887544274563075", "1433801716202344460", "1433799487592468492", "1433754869429592078",
           "1433120347176386561", "1432410673259057161", "1433115345938784263", "1433093342456389639", "1432961860731478017",
           "1432828362280476673", "1432812324709179394", "1432806681793159168", "1432721292403281920", "1432707208211537930",
           "1432700115299586053", "1432658875665289216", "1432623112747638785", "1432614035141312513", "1432612768717451266")

# UI ----------------------------------------------------------------------

ui <- fluidPage(
  # Input functions
  textInput(inputId = 'search_term',
            label = 'Search tweets from the last 6-9 days:',
            #value = 'covid',
            placeholder = '#covid-19',
            width = '90%'
  ),
  actionButton(inputId = 'submit_button',
               label = 'Submit'
  ),
  
  # Output functions 
  twitterwidgetOutput('twitter', width = "100%", height = "400px")
)

# Server ------------------------------------------------------------------

server <- function(input, output) {
  
  # Get data 
  tweet_id <- eventReactive(input$submit_button, {sample(v_ids, 1)})
 
  # Twitter widget
  output$twitter <- renderTwitterwidget(twitterwidget(tweet_id()))
  
}

shinyApp(ui, server)

Answer 1

奇怪的功能，不确定是包的问题还是什么。您也可以使用shinyjs并编写用户定义的javascript函数来清除div的内容。

下面是一个应该起作用的简单实现：

# Libraries ---------------------------------------------------------------

library(shiny)
library(twitterwidget)
library(tidyverse)
library(rtweet)

# UI ----------------------------------------------------------------------

ui <- fluidPage(
  shinyjs::useShinyjs(),
  shinyjs::extendShinyjs(
    text = "shinyjs.refresh = function() {
      var div = document.getElementById('twitter_output');
      while(div.firstChild){
          div.removeChild(div.firstChild);
        }
      }",
    functions = c("refresh")
  ),
  # Input functions
  textInput(
    inputId = 'search_term',
    label = 'Search tweets from the last 6-9 days:',
    #value = 'covid',
    placeholder = '#covid-19',
    width = '90%'
  ),
  actionButton(inputId = 'submit_button',
               label = 'Submit'),
  
  twitterwidgetOutput("twitter_output")
)

# Server ------------------------------------------------------------------

server <- function(input, output) {
  observeEvent(input$submit_button, {
    # Obtain tweet ID
    tweet_id <-
      search_tweets(q = input$search_term,
                    n = 1,
                    lang = 'en') %>%
      pull(status_id)
    
    # Refresh the `twitter_output` div
    shinyjs::js$refresh()
    
    # Render the tweet again.
    output$twitter_output <-
      renderTwitterwidget(twitterwidget(tweet_id))
  })
}

shinyApp(ui, server)