Call sv_optional() to generate a validation function that indicates an
input is allowed to not be present. If an sv_optional() rule sees that an
input is not present, subsequent rules for that input are skipped and the
input is considered valid. Otherwise, the rule simply passes.
(sv_optional() will never return a validation error/message.)
By default, the definition of "is present" is based on input_provided().
Child validators (see InputValidator$add_validator()) are
not affected by sv_optional() rules in parent validators; only rules in the
same validator instance as the sv_optional() will be skipped.
sv_optional(test = input_provided)A single-argument function, or single-sided formula (using . to
access the value to test), that returns TRUE for success and FALSE for
failure.
A function suitable for use as an
InputValidator$add_rule() rule.
The sv_required() function, which takes a different approach to
field presence.
Other rule functions:
compose_rules(),
sv_between(),
sv_email(),
sv_equal(),
sv_gte(),
sv_gt(),
sv_in_set(),
sv_integer(),
sv_lte(),
sv_lt(),
sv_not_equal(),
sv_numeric(),
sv_regex(),
sv_required(),
sv_url()
## Only run examples in interactive R sessions
if (interactive()) {
library(shiny)
library(shinyvalidate)
ui <- fluidPage(
textInput("email", "Email")
)
server <- function(input, output, session) {
# Validation rules are set in the server, start by
# making a new instance of an `InputValidator()`
iv <- InputValidator$new()
# Basic usage: `sv_optional()` is often paired with
# another `sv_*()` function; below, an email in
# `input$email` is not required, but if present, it
# must be valid
iv$add_rule("email", sv_optional())
iv$add_rule("email", sv_email())
# Finally, `enable()` the validation rules
iv$enable()
}
shinyApp(ui, server)
}