我试图切换显示/隐藏列按钮的标签,并跟踪单击它的次数以更改表格显示的列数。我做到了,但我不能使用计数器值的直接奇/偶微分。相反,我不得不使用这个:(vars$counter+1)/2) %% 2 == 0)
让它工作,因为每次点击都会改变计数器 2 次。我想要求一个更简单的程序,也许有一个闪亮的BS?
## app.R ##
library(shiny)
library(shinydashboard)
library(DT)
body<-dashboardBody(
textOutput("count"),
uiOutput('showallcolumnsbutton'),
DT::dataTableOutput('table2')
)
ui <- dashboardPage(
dashboardHeader(),
dashboardSidebar(),
body
)
server <- function(input, output) {
table<-data.frame(replicate(10,sample(0:1,1000,rep=TRUE)))
vars<-reactiveValues()
vars = reactiveValues(counter = 0)
observe({
if(!is.null(input$showallcolumns)){
input$showallcolumns
isolate({
vars$counter <- vars$counter + 1
})
}
})
label <- reactive({
if(!is.null(input$showallcolumns)){
if( ( (vars$counter+1)/2) %% 2 == 0) label <- "Hide"
else label <- "Show"
}
})
output$showallcolumnsbutton <- renderUI({
actionButton("showallcolumns", label = label(),
icon("hand-pointer-o"),
style="color: #000; background-color: #0099ff; border-color: #2e6da4"
)
})
output$count<-renderText({paste("counter value:",vars$counter)})
columnstoshow = reactive ({
x= ((vars$counter+1)/2) # %% 2 == 0)
if (!is.null (x))
{
if (x %% 2 == 0) {
c=c(1:10)
}
else {
c=c(1:5)
}
} #end 1st if
else {
c=c(1:10)
}
})
output$table2 = DT::renderDataTable({
DT::datatable(table[, columnstoshow()])
})
} # end server
shinyApp(ui, server)