在闪亮的应用程序外部创建反应功能 [英] Create a reactive function outside the shiny app

问题描述

我试图分解我闪亮的应用程序的代码，以提高可读性并使用testthat包测试某些功能.

I am trying to decompose the code of my shiny app in order to improve readability and to test some functions using the testthat package.

我想拥有一些文件(例如server_utils.R)，在其中可以编写可以测试的正常"功能，然后使它们具有反应性.

I would like to have some files (for example server_utils.R) in which I can write "normal" functions that I can test and then make them reactive.

例如，我想在server_utils.R中添加类似的内容:

For example I would like to have something like this in server_utils.R:

my_sum <- function(x, y) {
  x + y
}

以及类似的应用程序中的内容:

and something like this in the app:

my_sum_reactive(input$x, input$y)

您知道这种行为是否可能吗?

Do you know if a such behavior is possible?

推荐答案

发光的模块可能会帮助您.

Shiny modules is what might help you.

请参阅此处: https://shiny.rstudio.com/articles/modules.html

如您在文章中所读，如果将输入包装在reactive()函数中，则可以通过所需的功能来传递输入. (请参阅本文编写服务器功能"部分的末尾.)

As you can read in the article the desired functionality to pass in input is possible if you wrap the input in a reactive() function. (See the end of the "Writing server functions" section of the article).

您将定义my_sum函数，如下所示: (请注意，必须将变量a和b用作反应堆a()和b()，并将结果包装在reactive()函数中.)

You would define the my_sum function as follows: (Note that you have to use the variables a and b as reactives a() and b() and wrap the result in a reactive() function.)

my_sum <- function(input, output, session, a, b) {
  reactive(as.numeric(a()) + as.numeric(b()))
}

并且可以将其用作:

my_sum_reactive <- callModule(my_sum, "id", reactive(input$a), reactive(input$b))

然后可以用作:

my_sum_reactive()

可复制的示例:

library(shiny)

my_sum <- function(input, output, session, a, b) {
  reactive(as.numeric(a()) + as.numeric(b()))
}

ui <- fluidPage({
  fluidRow(
    selectInput("a", "a", 1:3),
    selectInput("b", "b", 1:3),
    textOutput("txt")
  )
})

server <- function(input, output, session) {
  my_sum_reactive <- callModule(my_sum, "id", reactive(input$a), reactive(input$b))
  output$txt <- renderText(paste0("The sum is: ", my_sum_reactive())) 
}
shinyApp(ui, server)

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