Shiny R切换selectInput时如何保留联动pickerInput的已选有效选项

实现方案 #

要实现跨周期保留有效选中项的效果，只需要在调用updatePickerInput时主动指定selected参数，保留原有已选值里符合当前周期可选范围的部分即可。

修改后的完整可运行代码如下：

library(shiny)
library(shinyWidgets)

choice_name <- c('UK','USA','UK','USA','BE','BE')
choice_id <- c(1, 2, 1, 2, 3, 3)
period <- c('period1', 'period1', 'period2', 'period3', 'period3', 'period3')
data <- data.frame(choice_name, choice_id, period)

choices_picker <- unique(data$choice_id)
names(choices_picker) <- unique(data$choice_name)


ui <- bootstrapPage(                
  absolutePanel(left = 10, bottom = 10, draggable = TRUE, 
                selectInput(inputId = "input_period", label = "Period",
                            choices = c("Period 1: X to Z" = "period1", "Period 2: X to Y" = "period2", "Period 3: X to X" = "period3"),
                            selected = "period1"),
                pickerInput(inputId = "picker_cty",
                            label = "Select Country",
                            choices = choices_picker,
                            multiple = TRUE),
  ))

server <- function(input, output, session) {
  
  # Reactive pickerInput ---------------------------------
  observeEvent(input$input_period, {
    
    data1 <- data[data$period == input$input_period,]
    datau <- unique(data$choice_id)
    data1u <- unique(data1$choice_id)
    
    disabled_choices <- ifelse(datau %in% data1u, 0,1)
    
    # 筛选当前有效已选值
    current_picked <- input$picker_cty
    keep_selected <- current_picked[current_picked %in% data1u]
    
    # 更新pickerInput，保留有效选中项
    updatePickerInput(session = session, 
                      inputId = "picker_cty",
                      choices = choices_picker,
                      selected = keep_selected,
                      choicesOpt = list(
                        disabled = disabled_choices,
                        style = ifelse(disabled_choices,
                                       yes = "color: rgba(119, 119, 119, 0.5);",
                                       no = "")
                      ))
  }, ignoreNULL=FALSE)
  
}

shinyApp(ui, server)

效果说明 #

• 选择period1时选中UK+USA，切换到period2后，UK属于period2的可选范围会保持选中，USA不在可选范围内会被自动排除
• 切换到period3时，原有选中的UK、USA都不在可选范围内会自动清空，仅保留属于当前周期的BE的选中状态（如果之前选过BE的话）

内容的提问来源于stack exchange，提问作者AnEostig