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Define stop conditions for survey questions

Source: R/server.R
sd_stop_if.Rd

This function is used to define custom stop conditions for survey questions. When a user attempts to navigate to the next page, these conditions are checked first (before required question checks). If any condition is TRUE (i.e., the stop condition is met), a modal dialog displays the corresponding error messages and highlights the invalid questions in red.

Usage

sd_stop_if(...)

Arguments

...

One or more formulas defining stop conditions. The left-hand side of each formula should be a condition that, when TRUE, will stop navigation and show an error (e.g., nchar(input$zip) != 5). The right-hand side should be the error message to display when the condition is TRUE.

Value

This function does not return a value; it sets up stop logic for the survey.

Details

The function performs the following:

  • Automatically determines which page each stop condition belongs to based on the input variables referenced in the conditions

  • Groups stop conditions by page and shows them together when multiple conditions are triggered on the same page

  • Displays error messages as a numbered list when multiple stop conditions are triggered on the same page, or as a single message for individual triggers

  • Highlights invalid question containers in red

  • Takes higher priority than required question checks - stop conditions are checked first before required question checks

See also

sd_show_if, sd_skip_if

Examples

if (interactive()) {
  library(surveydown)

  # Define a server with custom stop conditions
  server <- function(input, output, session) {

    sd_stop_if(
      # Stop if zip code is not exactly 5 digits
      nchar(input$zip) != 5 ~ "Zip code must be 5 digits",
      # Stop if year of birth is before 1900
      as.numeric(input$yob) < 1900 ~ "Year of birth must be after 1900",
      # Stop if phone number is not exactly 10 digits
      nchar(input$phone) != 10 ~ "Phone number must be 10 digits"
    )

    sd_server()
  }
}