r语言 - 当词云未在闪亮的应用程序中播放时显示文本消息

Question

在下面的闪亮应用程序中，我显示了一个词云和一个滑块，用于设置显示的单词数。当这个数字=1(input$max==1)时，什么都不显示。所以我想替换这个词云，我现在有一个renderUI()，它将在input$max==1时显示一条消息，在其他情况下将显示词云。

if(require(shiny)){
library(wordcloud2)
wordcloud2(data = demoFreq)

# Global variables can go here
n <- 1

# Define the UI
ui <- bootstrapPage(
sliderInput("max",
"Maximum Number of Words:",
min = 1,  max = nrow(demoFreq),  value =nrow(demoFreq),step=1 ),  
uiOutput("wordcloud2ortext"),
wordcloud2Output('wordcloud2')
)


# Define the server code
server <- function(input, output) {
output$wordcloud2 <- renderWordcloud2({
# wordcloud2(demoFreqC, size=input$size)
wordcloud2(demoFreq[1:input$max,])
})
output$wordcloud2ortext<-renderUI({
if(input$max==1){
"No words found"
}
else{
wordcloud2(demoFreq[1:input$max,])
}
})
}
# Return a Shiny app object
# Sys.setlocale("LC_CTYPE","chs") #if you use Chinese character
## Do not Run!
shinyApp(ui = ui, server = server)
}

Answer 1

你只需要注释掉其他输出(wordcloud2Output)：

if(require(shiny)) {
library(wordcloud2)
wordcloud2(data = demoFreq)

# Global variables can go here
n <- 1

# Define the UI
ui <- bootstrapPage(
sliderInput(
"max",
"Maximum Number of Words:",
min = 1,
max = nrow(demoFreq),
value = nrow(demoFreq),
step = 1
),
uiOutput("wordcloud2ortext")
# , wordcloud2Output('wordcloud2')
)


# Define the server code
server <- function(input, output) {

output$wordcloud2 <- renderWordcloud2({
# wordcloud2(demoFreqC, size=input$size)
wordcloud2(demoFreq[1:input$max, ])
})

output$wordcloud2ortext <- renderUI({
if (input$max == 1) {
strong("No words found")
}
else{
wordcloud2(demoFreq[1:input$max, ])
}
})

}
# Return a Shiny app object
# Sys.setlocale("LC_CTYPE","chs") #if you use Chinese character
## Do not Run!
shinyApp(ui = ui, server = server)
}