您好,很抱歉可能是一个基本的Shiny问题。
在我的迷你发光应用中,我希望用户:
使用selectInput()从预先存在的名称列表中选择一个名称。
仅当列表中没有记住她/他的名字时,我希望一个新的小部件出现在他/他应使用textInput()输入名称的位置。
我被困住了-我在UI端的mainPanel内部的verbatimTextOutput语句不起作用。
谢谢您的提示!
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$chosen_name == 'Name not on our list') return(NULL) else {
textInput("If the name you want is not on our list, type it here:")
}
})
})
shinyApp(ui = ui, server = server)
答案 0 :(得分:1)
您对ui端的功能有些困惑:
如果在服务器端使用renderUI()
,则必须在ui端使用uiOutput()
才能使其正常工作。另外,您应该避免使用相同的ID两次。最后,对于文本输入,我添加了一个ID和一个标签。
完整代码如下:
library(shiny)
ui = shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(
uiOutput("chosen_nm", label = h4("Select one of the names:"))
),
mainPanel( # Just shows what was selected
# Next two lines don't work if uncommented:
uiOutput("name_openend")
)
)
))
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
mynames <- c("John", "Mary", "Jim")
# Allow to select a name from the list of pre-existing names:
output$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$chosen_name == 'Name not on our list'){
textInput("newName", "If the name you want is not on our list, type it here:")
}else{
verbatimTextOutput('chosen_name2')
}
})
})
shinyApp(ui = ui, server = server)
答案 1 :(得分:1)
更新代码
library(shiny)
ui = shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(
selectInput("chosen_name", "select name", choices = ""),
uiOutput("new")
),
mainPanel(
textOutput("chosen")
)
)
))
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
mynames <- c("John", "Mary", "Jim")
observe({
updateSelectInput(session, inputId = "chosen_name", label = "Select a name:", choices = c(mynames, "Name not on our list"))
})
# Open end box to enter name - if the name the user wants to enter is not on the list:
output$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$Not_on_list))
}
})
})
shinyApp(ui = ui, server = server)
答案 2 :(得分:0)
为了使它正常工作,我需要切出一些东西。首先是sidebarLayout。这可能已经弄乱了您的mainPanel。我敢肯定,只要确保mainPanel放置在正确的位置并且没有被添加到sidebarLayout上,就可以使它起作用,这可能是问题所在。
还有其他一些问题,例如renderUI和UIOutput。也许其他人会添加有关如何使用这些功能的帖子。另外,我添加了一个反应函数,以便textOutput会改变。
看看我的工作原理。
mynames <- c("John", "Mary", "Jim")
ui = shinyUI(
fluidPage(
sidebarPanel(
selectInput('chosen_name',"Select a name:",
choices = c("Name not on our list", mynames),
selected = "Name not on our list")
),
mainPanel(
textOutput('chosen_name2')
)
)
)
server = shinyServer(function(input, output, session) {
# A vector of pre-existing names:
selectedchosen_name <- reactive({
if (input$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)
我删除了一些可能多余的部分,但是现在它已经简化了,因此可以添加到其中。如果你有问题,就问吧。