我有两个输出,一个打印和一个绘图。我想在按下运行按钮(工作)后执行打印,然后在打印完成时执行绘图部件。
原因是打印部件执行一些需要几分钟的计算,并且输出需要转到绘图命令。
简单示例:
library(shiny)
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
actionButton('run','Run')
),
mainPanel(
verbatimTextOutput("Descriptive"),
plotOutput("plotData",width = "700px", height = "500px")
)
)
)
server <- function(input, output) {
output$Descriptive <- renderPrint({
if(input$run>0){
return(isolate({
cat('Number of rows:', nrow(mtcars))
mpg2 <<- mtcars$mpg+3
cyl2 <<- mtcars$cyl+3
}))
}else{return(invisible())}
})
#### RUN AFTER DESCRIPTIVE COMPLETES ####
output$plotData <- renderPlot({
plot(mpg2,cyl2)
})
}
shinyApp(ui = ui, server = server)
答案 0 :(得分:1)
我建议你将变量存储为reactiveValues并使图依赖于它们。通过这种方式,您可以避免当前的全局分配,并使绘图更新依赖于其变量的变化。
看起来像这样:
global <- reactiveValues(mpg2 = mtcars$mpg, cyl2 = mtcars$cyl, txt = "")
observe({
if(input$run > 0){
Sys.sleep(5) # simulate minutes of calculating
global$txt <- paste('Number of rows:', nrow(mtcars))
global$mpg2 <- mtcars$mpg + 3
global$cyl2 <- mtcars$cyl + 3
}
})
您的应用看起来像这样:
library(shiny)
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
actionButton('run','Run')
),
mainPanel(
verbatimTextOutput("Descriptive"),
plotOutput("plotData",width = "700px", height = "500px")
)
)
)
server <- function(input, output) {
global <- reactiveValues(mpg2 = mtcars$mpg, cyl2 = mtcars$cyl, txt = "")
observe({
if(input$run > 0){
Sys.sleep(5) # simulate minutes of calculating
global$txt <- paste('Number of rows:', nrow(mtcars))
global$mpg2 <- mtcars$mpg + 3
global$cyl2 <- mtcars$cyl + 3
}
})
output$Descriptive <- renderPrint({
if(nchar(global$txt)) return(global$txt)
})
#### RUN AFTER DESCRIPTIVE COMPLETES ####
output$plotData <- renderPlot({
plot(global$mpg2, global$cyl2)
})
}
shinyApp(ui = ui, server = server)