如何使用 actionButton 更改 R Shiny 中 selectInput 上的选定值？

如何解决如何使用 actionButton 更改 R Shiny 中 selectInput 上的选定值？

我正在构建一个闪亮的应用程序，其中包含一个包含项目列表的选择输入。默认情况下，选择数据中的所有项目。我想要 2 个操作按钮来帮助用户。一个重置为默认值并已全部选中（我已经弄清楚了），另一个删除了所有内容，而是将 selectInput 更改为“请选择至少一个项目”（这实际上与删除所有选项相同，因为没有具有该名称的项目）。第二个按钮我想不出来。

我的代码如下，非常感谢任何帮助：

library(shiny)
library(shinyjs)

test <- tibble(project = c("Justin","Corey","Sibley"),april_2021 = c(10,100,101),may_2021 = c(1,4,7))

ui <- fluidPage(
    useShinyjs(),sidebarLayout(
        sidebarPanel(
            div(id = "project_inputs",selectInput(inputId = "filter_by_project",label = "Filter by Project",choices = c(sort(unique(test$project)),"Please Select at Least One Project"),multiple = TRUE,selected = sort(unique(test$project)))),#I can't figure out the remove_all button
            actionButton(inputId = "remove_all",label = "Unselect All Projects",style = "color: #FFFFFF; background-color: #CA001B; border_color: #CA001B"),actionButton(inputId = "add_all",label = "Select All Projects",),mainPanel(
        )
    )
)

server <- function(input,output) {
    
#This is where the remove_all will go

    observeEvent(input$remove_all,{
        reset("add_all")
    })
}

shinyApp(ui = ui,server = server)

解决方法

试试这个

  library(shiny)
  library(shinyjs)
  
  test <- tibble(project = c("Justin","Corey","Sibley"),april_2021 = c(10,100,101),may_2021 = c(1,4,7))
  
  ui <- fluidPage(
    useShinyjs(),sidebarLayout(
      sidebarPanel(
        div(id = "project_inputs",selectizeInput(inputId = "filter_by_project",label = "Filter by Project",choices = sort(unique(test$project)),multiple = TRUE,selected = unique(test$project)[1] )),#I can't figure out the remove_all button
        actionButton(inputId = "remove_all",label = "Unselect All Projects",style = "color: #FFFFFF; background-color: #CA001B; border_color: #CA001B"),actionButton(inputId = "add_all",label = "Select All Projects",),mainPanel(
      )
    )
  )
  
  server <- function(input,output,session) {
    
    observeEvent(input$remove_all,{
      updateSelectizeInput(session,"filter_by_project",choices=sort(unique(test$project)),selected=NULL,options = list(placeholder="Please Select at Least One Project")
                        )
    })
    observeEvent(input$add_all,selected=sort(unique(test$project)) )
    })
  }
  
  shinyApp(ui = ui,server = server)