改变选择选择但保留以前选择的值
问题
我有两个下拉列表，dd2中可用的选项是以dd1中选择的选项为条件的。我无法弄清楚如何更改下拉菜单2的选项，但保留已经做出的任何选择。我也应该能够通过下拉列表2从之前的选择中删除项目。
示例
让我们说dd1是国家：印度，英国，美国以及dd2，城市中的相应选项:(新德里，孟买），（伦敦，伯明翰），（纽约，华盛顿特区）。我首先选择印度，然后是孟买，然后选择英格兰，保留孟买，然后加入伦敦。然后我以类似的方式添加纽约。我现在意识到我并不需要孟买，所以我将其删除，留给我在纽约的伦敦。
尝试失败
我正在尝试将选择附加到先前存在的向量并将两个向量的交集传递给所选择的＆＃39;争论，但它似乎不起作用。我猜测这样做的循环性质可能会导致问题。
基本代码
为了节省你们一些时间，让我们有相同的参考 -
# server.r
library(shiny)
library(data.table)
countrycity = data.table(
country = c('India','India','England','England','USA','USA'),
city = c('New Delhi','Mumbai','London','Birmingham','New York','Washington DC')
)
shinyServer(function(input, output) {
# dd1: country
output$chooseCountry <- renderUI({
selectizeInput(
"countrSelected",
"Country",
as.list(c('All',unique(unique(countrycity$country)))),
options = list(create = TRUE),
selected = c('All'),
multiple = TRUE,
width="120px"
)
})
# filtering list of cities based on the country selected
citiestoshow = reactive({
countryselected = if ( is.null(input$countryselected) ) {
unique(countrycity$country)
} else if ( 'All' %in% input$countryselected ) {
unique(countrycity$country)
} else {
input$countryselected
}
countrycity[country %in% countryselected, city]
})
# dd2: city
output$choosecities <- renderUI({
selectizeInput(
'cityselected',
label = 'City',
choices = as.list(c('All',citiestoshow())),
options = list(create = TRUE),
multiple = TRUE,
width="120px"
)
})
}
2 个答案:
答案 0 :(得分：3)
如果有人仍在寻找一个简单的例子来更新选择，同时保持以前选择的值：
#in ui.R you have a selectInput that you want to update
selectInput(inputId = "mymenu", label = "My Menu",
choices = c("A" = "a","B" = "b","C" = "c"),
selected = c("A" = "a"))
# in server.R create reactiveVal
current_selection <- reactiveVal(NULL)
# now store your current selection in the reactive value
observeEvent(input$mymenu, {
current_selection(input$mymenu)
})
#now if you are updating your menu
updateSelectInput(session, inputId = "mymenu",
choices = c("A" = "a","B" = "b","C" = "c", "D" = "d"),
selected = current_selection())
答案 1 :(得分：2)
以下是应该执行此操作的一个实现（更多详细信息here）：
runApp(list(ui={shinyUI(pageWithSidebar(
headerPanel("shinyUI"),
sidebarPanel(
uiOutput("choose_country"),
uiOutput("choose_city")
),
mainPanel(
headerPanel("mainPanel")
)
))},
server={
#Consider creating a file.
countries <- c('India','England','USA')
countrycity<-list()
countrycity[[countries[1]]]<-c('New Delhi','Mumbai')
countrycity[[countries[2]]]<-c('London','Birmingham')
countrycity[[countries[3]]]<-c('New York','Washington DC')
shinyServer(function(input, output) {
# Drop-down selection box for which data set
output$choose_country <- renderUI({
selectInput("choose_country", "Select Country", as.list(countries))
})
# Check boxes
output$choose_city <- renderUI({
# If missing input, return to avoid error later in function
if(is.null(input$choose_country))
return()
# Get the data set with the appropriate name
selected_country <- input$choose_country
cities<-countrycity[[selected_country]]
# Create the checkboxes and select them all by default
selectInput("choose_city", "Choose city",
choices = as.list(cities))
})
})}
))
更新1（保留以前的选择 - 粗略版本）：
runApp(list(ui={
library(shiny)
#ui.R
ui.r<-shinyUI(pageWithSidebar(
headerPanel("shinyUI"),
sidebarPanel(
uiOutput("choose_country"),
uiOutput("choose_city")
,actionButton('add','Add City')
),
mainPanel(
headerPanel("mainPanel")
, checkboxGroupInput('currentselection', 'Current Selection', choices = c('None'),selected=c(''))
)
))
},
server={
library(shiny)
#server.R
countries <- c('India','England','USA')
countrycity<-list()
countrycity[[countries[1]]]<-c('New Delhi','Mumbai')
countrycity[[countries[2]]]<-c('London','Birmingham')
countrycity[[countries[3]]]<-c('New York','Washington DC')
#Alphabetize (Optional)
order_cities<-order(countries)
countries<-countries[order_cities]
countrycity<-countrycity[order_cities]
countrycity<-lapply(countrycity,sort)
server.ui<-shinyServer(function(input, output,session) {
# Drop-down selection box for Country Selection
output$choose_country <- renderUI({
selectInput("choose_country", "Select Country", as.list(countries))
})
# City Selection
output$choose_city <- renderUI({
# If missing input, return to avoid error later in function
if(is.null(input$choose_country))
return()
# Get the data set with the appropriate name
selected_country <- input$choose_country
cities<-countrycity[[selected_country]]
# Create the drop-down menu for the city selection
selectInput("choose_city", "Choose city",
choices = as.list(cities))
})
##Keep previous selections in a session
lvl<-reactive(unlist(input$currentselection))
observe({
if(input$add==0) return()
isolate({
current_selection<-paste(input$choose_city,input$choose_country,sep=", ")
updateCheckboxGroupInput(session, "currentselection", choices = c(current_selection,lvl())
,selected=c(current_selection,lvl()))
})#iso
})#obs
observe({
updateCheckboxGroupInput(session, "currentselection", choices = unique(c(lvl()))
,selected=c(lvl()))
})
})
}
))
更新2：
runApp(list(ui={
library(shiny)
#ui.R
ui.r<-shinyUI(
pageWithSidebar(
headerPanel("shinyUI"),
sidebarPanel(
uiOutput("choose_country"),
uiOutput("choose_city")
),
mainPanel(
headerPanel("mainPanel")
#, checkboxGroupInput('currentselection', 'Current Selection', choices = c('None'),selected=c(''))
)
))
},
server={
library(shiny)
#server.R
countries <- c('India','England','USA')
countrycity<-list()
countrycity[[countries[1]]]<-c('None','New Delhi','Mumbai')
countrycity[[countries[2]]]<-c('None','London','Birmingham')
countrycity[[countries[3]]]<-c('None','New York','Washington DC')
#Alphabetize (Optional)
order_cities<-order(countries)
countries<-countries[order_cities]
countrycity<-countrycity[order_cities]
countrycity<-lapply(countrycity,sort)
server.ui<-shinyServer(function(input, output,session) {
session$countrycitySelection<-list()
for(country in countries){
session$countrycitySelection[[country]]<-'None'
}
# Drop-down selection box for Country Selection
output$choose_country <- renderUI({
selectInput("choose_country", "Select Country", as.list(countries))
})
# City Selection
output$choose_city <- renderUI({
# If missing input, return to avoid error later in function
if(is.null(input$choose_country))
return()
# Get the data set with the appropriate name
selected_country <- input$choose_country
cities<-countrycity[[selected_country]]
# Create the drop-down menu for the city selection
selectInput("choose_city", "Choose city",
choices = as.list(cities),selected = NULL, multiple = FALSE,
selectize = TRUE, width = NULL)
})
#changing country selection
observe({
country <- input$choose_country
if(is.null(country)) return()
isolate({
updateSelectInput(session, "choose_city", choices = countrycity[[country]]
,selected = session$countrycitySelection[[country]] )
})#iso
})#obs
#changing city selection
observe({
city <- input$choose_city
if(is.null(city)) return()
isolate({
country<-input$choose_country
session$countrycitySelection[[country]]<-city
})#iso
})#obs
})
}
))
更新3：（2016） Shiny不再允许向会话添加值，因此这与反应性相同：
runApp(list(ui={
library(shiny)
#ui.R
ui.r<-shinyUI(
pageWithSidebar(
headerPanel("shinyUI"),
sidebarPanel(
uiOutput("choose_country"),
uiOutput("choose_city")
),
mainPanel(
headerPanel("mainPanel")
#, checkboxGroupInput('currentselection', 'Current Selection', choices = c('None'),selected=c(''))
)
))
},
server={
library(shiny)
#server.R
countries <- c('India','England','USA')
countrycity<-list()
countrycity[[countries[1]]]<-c('None','New Delhi','Mumbai')
countrycity[[countries[2]]]<-c('None','London','Birmingham')
countrycity[[countries[3]]]<-c('None','New York','Washington DC')
#Alphabetize (Optional)
order_cities<-order(countries)
countries<-countries[order_cities]
countrycity<-countrycity[order_cities]
countrycity<-lapply(countrycity,sort)
countrycitySelection<-list()
for(country in countries){
countrycitySelection[[country]]<-'None'
}
server.ui<-shinyServer(function(input, output,session) {
values <- reactiveValues(countrycitySelection = countrycitySelection)
# Drop-down selection box for Country Selection
output$choose_country <- renderUI({
selectInput("choose_country", "Select Country", as.list(countries))
})
# City Selection
output$choose_city <- renderUI({
# If missing input, return to avoid error later in function
if(is.null(input$choose_country))
return()
# Get the data set with the appropriate name
selected_country <- input$choose_country
cities<-countrycity[[selected_country]]
# Create the drop-down menu for the city selection
selectInput("choose_city", "Choose city",
choices = as.list(cities),selected = NULL, multiple = FALSE,
selectize = TRUE, width = NULL)
})
#changing country selection
observe({
country <- input$choose_country
if(is.null(country)) return()
isolate({
updateSelectInput(session, "choose_city", choices = countrycity[[country]]
,selected = values$countrycitySelection[[country]] )
})#iso
})#obs
#changing city selection
observe({
city <- input$choose_city
if(is.null(city)) return()
isolate({
country<-input$choose_country
values$countrycitySelection[[country]]<-city
})#iso
})#obs
})
}
))
相关问题
最新问题
- 我写了这段代码，但我无法理解我的错误
- 我无法从一个代码实例的列表中删除 None 值，但我可以在另一个实例中。为什么它适用于一个细分市场而不适用于另一个细分市场？
- 是否有可能使 loadstring 不可能等于打印？卢阿
- java中的random.expovariate()
- Appscript 通过会议在 Google 日历中发送电子邮件和创建活动
- 为什么我的 Onclick 箭头功能在 React 中不起作用？
- 在此代码中是否有使用“this”的替代方法？
- 在 SQL Server 和 PostgreSQL 上查询，我如何从第一个表获得第二个表的可视化
- 每千个数字得到
- 更新了城市边界 KML 文件的来源？