R: Text Output

renderText {shiny} | R Documentation

## Text Output

### Description

Makes a reactive version of the given function that also uses `cat` to turn its result into a single-element character vector.

### Usage

    renderText(expr, env = parent.frame(), quoted = FALSE,
      outputArgs = list())

### Arguments

`expr` | An expression that returns an R object that can be used as an argument to `cat`.
`env` | The environment in which to evaluate `expr`.
`quoted` | Is `expr` a quoted expression (with `quote()`)? This is useful if you want to save an expression in a variable.
`outputArgs` | A list of arguments to be passed through to the implicit call to `textOutput` when `renderText` is used in an interactive R Markdown document.

### Details

The corresponding HTML output tag can be anything (though `pre` is recommended if you need a monospace font and whitespace preserved) and should have the CSS class name `shiny-text-output`.

The result of executing `func` will passed to `cat`, inside a `capture.output` call.

### See Also

`renderPrint` for capturing the print output of a function, rather than the returned text value.

### Examples

    isolate({

    # renderPrint captures any print output, converts it to a string, and
    # returns it
    visFun <- renderPrint({ "foo" })
    visFun()
    # '[1] "foo"'

    invisFun <- renderPrint({ invisible("foo") })
    invisFun()
    # ''

    multiprintFun <- renderPrint({
      print("foo");
      "bar"
    })
    multiprintFun()
    # '[1] "foo"\n[1] "bar"'

    nullFun <- renderPrint({ NULL })
    nullFun()
    # 'NULL'

    invisNullFun <- renderPrint({ invisible(NULL) })
    invisNullFun()
    # ''

    vecFun <- renderPrint({ 1:5 })
    vecFun()
    # '[1] 1 2 3 4 5'

    # Contrast with renderText, which takes the value returned from the function
    # and uses cat() to convert it to a string
    visFun <- renderText({ "foo" })
    visFun()
    # 'foo'

    invisFun <- renderText({ invisible("foo") })
    invisFun()
    # 'foo'

    multiprintFun <- renderText({
      print("foo");
      "bar"
    })
    multiprintFun()
    # 'bar'

    nullFun <- renderText({ NULL })
    nullFun()
    # ''

    invisNullFun <- renderText({ invisible(NULL) })
    invisNullFun()
    # ''

    vecFun <- renderText({ 1:5 })
    vecFun()
    # '1 2 3 4 5'

    })

[Package shiny version 1.0.5 Index]