Validate that a field is equal to a specified value

The sv_equal() function compares the field value to a specified value with the == operator.

sv_equal(
  rhs,
  message_fmt = "Must be equal to {rhs}.",
  allow_multiple = FALSE,
  allow_na = FALSE,
  allow_nan = FALSE,
  allow_inf = FALSE
)

Arguments

rhs

The right hand side (RHS) value is to be used for the comparison with the field value. The validation check will effectively be of the form <field> == <rhs>.

message_fmt

The validation error message to use if the field fails the validation test. Use the "{rhs}" string parameter to customize the message, including what was set in rhs. While the default message uses this string parameter, it is not required in a user-defined message_fmt string.

allow_multiple

If FALSE (the default), then the length of the input vector must be exactly one; if TRUE, then any length is allowed (including a length of zero; use sv_required() if one or more values should be required).

allow_na, allow_nan

If FALSE (the default for both options), then any NA or NaN element will cause validation to fail.

allow_inf

If FALSE (the default), then any Inf or -Inf element will cause validation to fail.

Value

A function suitable for use as an InputValidator$add_rule() rule.

See also

The other comparison-based rule functions: sv_gt(), sv_gte(), sv_lt(), sv_lte(), and sv_not_equal() (which serves as the opposite function to sv_equal()).

Other rule functions: compose_rules(), sv_between(), sv_email(), sv_gte(), sv_gt(), sv_in_set(), sv_integer(), sv_lte(), sv_lt(), sv_not_equal(), sv_numeric(), sv_optional(), sv_regex(), sv_required(), sv_url()

Examples

## Only run examples in interactive R sessions
if (interactive()) {

library(shiny)
library(shinyvalidate)

ui <- fluidPage(
  textInput("number", "Number")
)

server <- function(input, output, session) {
  
  # Validation rules are set in the server, start by
  # making a new instance of an `InputValidator()`
  iv <- InputValidator$new()

  # Basic usage: `sv_equal()` requires a value
  # to compare against the field value; a message
  # will be shown if the validation of
  # `input$number` fails
  iv$add_rule("number", sv_equal(1))

  # Finally, `enable()` the validation rules
  iv$enable()
}

shinyApp(ui, server)

}