在具有多个交互的闪亮动态 UI 算法方面需要帮助

Question

My Shiny Algorithm(app.底部的 R 代码)：

• 要求用户上传文件
• 提供带有选项"无"，"国家"，"州"，"城市"的下拉字段
• 选择"无"时，应仅显示文本输出
• 选择"国家/地区"后，应仅显示国家/地区过滤器
• 选择"州"后，应同时显示国家/地区和州过滤器
选择
• "城市"后，应同时显示国家/地区和城市过滤器，并且以前选择的任何现有州过滤器都应消失

我在代码中做了什么： 对"无"和"国家"使用 IF 条件;将开关用于"州"和"城市"。

我的问题：一切都按预期工作，除了一个：如果我们在选择"无"后选择"状态"，我会看到文本输出和状态过滤器，而不是国家和州过滤器。发生这种情况是因为与 switch() 不同，"None"或"Country"中的 IF 语句只打印 UI，如果进行其他选择，则不会清除 UI

我的约束：

• 国家/地区过滤器输入需要在代码中重复("州" 应该同时提供国家和州过滤器，同样适用于"城市")但 我们不能在闪亮的代码中复制具有相同 ID 的输入

• 我不能使用不同的国家/地区过滤器 ID 来提供相同的输入 因为我需要读取国家/地区过滤器中的输入值 多个地方，我需要复制所有这些地方 会使一切复杂化

我需要帮助的地方：我在这里唯一的问题是，如果用户在"无"(绕过"国家"!!)之后选择("州"/"城市")后，我需要同时显示"国家"和("州"/"城市")过滤器。

真的需要这个东西来修复。任何帮助将不胜感激

谢谢！

虚拟数据：https://docs.google.com/spreadsheets/d/1E9dbtOMm1-7ZjIHu3Ra_NyFBHrCQdITG2_xuMIMKDOs/edit?usp=sharing

.app。R 代码

library(shiny)
ui <- fluidPage(
fileInput("file_attr", "Door attributes:"),
selectInput("select", label = "Region Drop down", choices = list("None", "Country", "State","City"), selected = "None"),
uiOutput("NoneCountryFilter"),
uiOutput("StateCityFilter")
)
server <- function(input, output, session) {
#Reading input
data_attr <- reactive({
file1 <- input$file_attr
if(is.null(file1)){return()} 
read.table(file=file1$datapath, sep=",", header = TRUE, stringsAsFactors = FALSE)
})
#Filter interactivity
#Reading Lists
countries <- reactive({
if(is.null(data_attr()$Country)){return()}
data_attr()$Country
})
states <- reactive({
if(is.null(data_attr()$State)){return()}
data_attr()$State[data_attr()$Country %in% input$show_vars]
})
cities <- reactive({
if(is.null(data_attr()$City)){return()}
data_attr()$City[data_attr()$Country %in% input$show_vars]
})

#Filters based on Region Drop down
observeEvent(input$file_attr,{ 
observe({
if ("None" %in% input$select){
output$NoneCountryFilter <- renderUI({
if(is.null(data_attr()$Country)){return()}
h4("No region Selected")              
})        
}
if ("Country" %in% input$select){
output$NoneCountryFilter <- renderUI({
if(is.null(data_attr()$Country)){return()}
selectizeInput('show_vars', 'Country Filter', choices = c("Select All","None", unique(countries())), multiple = TRUE)
})    
}        
})
output$StateCityFilter <- renderUI({
switch(input$select,                
"State" = (
selectizeInput('show_vars_state', 'State Filter', choices = c("Select All","None", unique(states())), multiple = TRUE)
),
"City" = (
selectizeInput('show_vars_city', 'City Filter', choices = c("Select All","None", unique(cities())), multiple = TRUE)
)         
)         
})       
})
#Giving "Select ALL" and "None" Functionality to each filter (This part is redundant for the current problem. I am keeping this so that I could check any solution from stackoverflow should not effect other functionalities)
#Countries- SelectAll & None
observe({
if ("Select All" %in% input$show_vars){
selected_choices <- setdiff(c("Select All",unique(countries())), "Select All")
updateSelectizeInput(session, 'show_vars', choices = c("Select All","None",unique(countries())), selected = selected_choices) 
}
})  

observe({
if ("None" %in% input$show_vars){
updateSelectizeInput(session, 'show_vars', choices = c("Select All", "None", unique(countries())),selected = "")
}
})

#State- SelectAll & None
observe({
if ("Select All" %in% input$show_vars_state){
selected_choices <- setdiff(c("Select All",unique(states())), "Select All")
updateSelectizeInput(session, 'show_vars_state', choices = c("Select All","None",unique(states())), selected = selected_choices)
}
})
observe({
if ("None" %in% input$show_vars_state){
updateSelectizeInput(session, 'show_vars_state', choices = c("Select All", "None", unique(states())),selected = "")
}
})        
#City- SelectAll & None
observe({
if ("Select All" %in% input$show_vars_city){
selected_choices <- setdiff(c("Select All",unique(cities())), "Select All")
updateSelectizeInput(session, 'show_vars_city', choices = c("Select All", "None", unique(cities())), selected = selected_choices)
}
})
observe({
if ("None" %in% input$show_vars_city){
updateSelectizeInput(session, 'show_vars_city', choices = c("Select All", "None", unique(cities())),selected = "")
}
})    
}
shinyApp(ui = ui, server = server)

Answer 1

您可以使用conditionalPanel来确定要根据特定条件显示哪些元素。

笔记：

• 我在data_attr中使用了req()，因为这是对file_attr的检查。您不必使用is.null().

• 我为国家/地区、州、城市使用了三个conditionalPanel，并为每个指定了条件。

• 在条件内部，input.select使用不input$select。

---

library(shiny)
ui <- fluidPage(
fileInput("file_attr", "Door attributes:"),
selectInput("select", label = "Region Drop down",
choices = list("None", "Country", "State","City"), selected = "None"),
# Selectize Inputs ---------------
uiOutput("Country_List"),
uiOutput("State_List"),
uiOutput("City_List")
)
server <- function(input, output, session) {
#Reading input
data_attr <- reactive({
req(input$file_attr) # make sure a file was uploaded
read.table(file=input$file_attr$datapath, sep=",", header = TRUE, stringsAsFactors = FALSE)
})
# Country selectizeInput ----------------------
output$Country_List <- renderUI({
conditionalPanel(
condition = "input.select == 'Country' | input.select == 'State'| input.select == 'City' ",
selectizeInput('show_var', 'Country Filter',
choices = c("Select All","None", unique(data_attr()$Country)), multiple = TRUE)
)
})
# State selectizeInput ----------------------
output$State_List <- renderUI({
conditionalPanel(
condition = "input.select == 'State' ",
selectizeInput('show_vars_state', 'State Filter',
choices = c("Select All","None", unique(data_attr()$State)), multiple = TRUE)
)
})
# City selectizeInput -----------------------
output$City_List <- renderUI({
conditionalPanel(
condition = "input.select == 'City' ",
selectizeInput('show_vars_city', 'City Filter',
choices = c("Select All","None", unique(data_attr()$City)), multiple = TRUE)
)
})
}
shinyApp(ui = ui, server = server)