renderText

From shiny v1.5.0 by Winston Chang

Text Output

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

Usage

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

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.
sep: A separator passed to cat to be appended after each element.

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 utils::capture.output() call.

Examples

# NOT RUN {
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'

})
# }

Documentation reproduced from package shiny, version 1.5.0, License: GPL-3 | file LICENSE

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