R: Register expressions for export in test mode

exportTestValues {shiny} | R Documentation

## Register expressions for export in test mode

### Description

This function registers expressions that will be evaluated when a test export event occurs. These events are triggered by accessing a snapshot URL.

### Usage

    exportTestValues(..., quoted_ = FALSE, env_ = parent.frame(),
      session_ = getDefaultReactiveDomain())

### Arguments

`...` | Named arguments that are quoted or unquoted expressions that will be captured and evaluated when snapshot URL is visited.
`quoted_` | Are the expression quoted? Default is `FALSE`.
`env_` | The environment in which the expression should be evaluated.
`session_` | A Shiny session object.

### Details

This function only has an effect if the app is launched in test mode. This is done by calling `runApp()` with `test.mode=TRUE`, or by setting the global option `shiny.testmode` to `TRUE`.

### Examples

    ## Only run this example in interactive R sessions
    if (interactive()) {

    options(shiny.testmode = TRUE)

    # This application shows the test snapshot URL; clicking on it will
    # fetch the input, output, and exported values in JSON format.
    shinyApp(
      ui = basicPage(
        h4("Snapshot URL: "),
        uiOutput("url"),
        h4("Current values:"),
        verbatimTextOutput("values"),
        actionButton("inc", "Increment x")
      ),

      server = function(input, output, session) {
        vals <- reactiveValues(x = 1)
        y <- reactive({ vals$x + 1 })

        observeEvent(input$inc, {
          vals$x <<- vals$x + 1
        })

        exportTestValues(
          x = vals$x,
          y = y()
        )

        output$url <- renderUI({
          url <- session$getTestSnapshotUrl(format="json")
          a(href = url, url)
        })

        output$values <- renderText({
          paste0("vals$x: ", vals$x, "\ny: ", y())
        })
      }
    )
    }

[Package shiny version 1.0.5 Index]