您好，对不起可能是一个基本的闪亮问题。
在我的迷你闪亮应用程序中，我希望用户：
我被卡住了 - 我在UI侧的mainPanel内的verbatimTextOutput语句无效。
谢谢你的提示！
library(shiny)
ui = shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(
uiOutput("chosen_name", label = h4("Select one of the names:"))
),
mainPanel( # Just shows what was selected
# Next two lines don't work if uncommented:
# verbatimTextOutput('chosen_name')
# verbatimTextOutput("name_openend")
)
)
))
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
mynames <- c("John", "Mary", "Jim")
# Allow to select a name from the list of pre-existing names:
output$chosen_name <- renderUI({
selectInput('chosen_name',"Select a name:",
choices = c("Name not on our list", mynames),
selected = "Name not on our list")
})
# Open end box to enter name - if the name the user wants to enter is not on the list:
output$name_openend <- renderUI({
if (!output$chosen_name == 'Name not on our list') return(NULL) else {
textInput("If the name you want is not on our list, type it here:")
}
})
})
shinyApp(ui = ui, server = server)
更新的代码
library(shiny)
ui = shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(
selectInput("chosen_name", "select name", choices = ""),
uiOutput("new")
),
mainPanel(
textOutput("chosen")
)
)
))
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
mynames <- c("John", "Mary", "Jim")
observe({
updateSelectInput(session, inputId = "chosen_name", label = "Select a name:", choices = c(mynames, "Name not on our list"))
})
# Open end box to enter name - if the name the user wants to enter is not on the list:
output$new <- renderUI({
if (!input$chosen_name == 'Name not on our list') return(NULL) else {
textInput("Not_on_list", "If the name you want is not on our list, type it here:")
}
})
#
#
# Allow to select a name from the list of pre-existing names:
output$chosen <- renderText({
if (!input$chosen_name == 'Name not on our list') {
return(paste("Chosen name:", input$chosen_name))
}
else {
return(paste("Chosen name:", input$Not_on_list))
}
})
})
shinyApp(ui = ui, server = server)
你对ui方面的功能感到困惑：如果你在服务器端使用renderUI()，你将不得不在ui端使用uiOutput()来使它工作。此外，您应该避免使用相同的ID两次。最后，对于textinput，我添加了一个id和一个标签。
完整代码如下：
library(shiny)
ui = shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(
uiOutput("chosen_nm", label = h4("Select one of the names:"))
),
mainPanel( # Just shows what was selected
# Next two lines don't work if uncommented:
uiOutput("name_openend")
)
)
))
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
mynames <- c("John", "Mary", "Jim")
# Allow to select a name from the list of pre-existing names:
output$chosen_nm <- renderUI({
selectInput('chosen_name',"Select a name:",
choices = c("Name not on our list", mynames),
selected = "Name not on our list")
})
output$chosen_name2 <- renderText({
paste("The chosen name is: ", input$chosen_name)
})
# Open end box to enter name - if the name the user wants to enter is not on the list:
output$name_openend <- renderUI({
req(input$chosen_name)
if (input$chosen_name == 'Name not on our list'){
textInput("newName", "If the name you want is not on our list, type it here:")
}else{
verbatimTextOutput('chosen_name2')
}
})
})
shinyApp(ui = ui, server = server)
有一些事情我需要削减才能使其发挥作用。首先是sidebarLayout。这可能是你的主面板搞乱了。我相信你可以让它工作只是确保mainPanel在正确的位置，而不是添加到sidebarLayout，这可能是问题。
还有一些其他问题，如renderUI和UIOutput。也许其他人会添加关于如何使用这些功能的帖子。另外，我添加了一个反应函数，因此textOutput会改变。
看看我的工作方式。
mynames <- c("John", "Mary", "Jim")
ui = shinyUI(
fluidPage(
sidebarPanel(
selectInput('chosen_name',"Select a name:",
choices = c("Name not on our list", mynames),
selected = "Name not on our list")
),
mainPanel(
textOutput('chosen_name2')
)
)
)
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
selectedchosen_name <- reactive({
if (input$chosen_name == 'Name not on our list') {return("Pick a name")} else {
return("If the name you want is not on our list, type it here:")
}
})
# Allow to select a name from the list of pre-existing names:
output$chosen_name2 <- renderText({
selectedchosen_name()
})
# Open end box to enter name - if the name the user wants to enter is not on the list:
})
shinyApp(ui = ui, server = server)
我删除了一些可能是多余的部分，但是现在它已经简化了，所以你可以添加它。如果你有问题，就问吧。