Server logic for a surveydown survey

Usage

sd_server(db = NULL)

Arguments

db

A list containing database connection information created using sd_database() function. Defaults to NULL. If NULL, will be auto-detected from the calling environment or remain NULL (ignore mode).

Value

This function does not return a value; it sets up the server-side logic for the 'shiny' application and exposes the all_data reactive list in the parent environment.

Details

The function performs the following tasks:

• Initializes variables and reactive values, including the all_data reactive list for accessing question responses.

• Implements conditional display logic for questions.

• Tracks answered questions and updates the progress bar.

• Handles page navigation and skip logic.

• Manages required questions.

• Performs database operation.

• Controls auto-scrolling behavior based on survey settings.

• Uses sweetalert for warning messages when required questions are not answered.

• Handles the exit survey process based on survey settings.

All survey behavior is configured through the survey-settings section in the survey.qmd YAML header. Available settings include:

• show-previous: Show Previous button (default: FALSE)

• use-cookies: Enable cookie-based session management (default: TRUE)

• auto-scroll: Auto-scroll to next question (default: FALSE)

• rate-survey: Show rating question on exit (default: FALSE)

• all-required: Make all questions required (default: FALSE)

• start-page: ID of the page to start on (default: first page)

• system-language: Language for system messages (default: "en")

• highlight-unanswered: Highlight unanswered questions (default: TRUE)

• highlight-color: Color for highlighting (default: "gray")

• capture-metadata: Capture browser/IP info (default: TRUE)

• required: Vector of required question IDs

• shuffled: Vector of question IDs to shuffle (MC options or matrix rows)

• all-shuffled: Shuffle all MC options and matrix rows (default: FALSE)

Progress Bar

The progress bar is updated based on the last answered question. It will jump to the percentage corresponding to the last answered question and will never decrease, even if earlier questions are answered later. The progress is calculated as the ratio of the last answered question's index to the total number of questions.

Database Operations

If db is provided, the function will update the database with survey responses. If db is NULL (ignore mode), responses will be saved to a local CSV file.

Accessing Question Values

The sd_server() function exposes the all_data reactive values list that provides a reliable way to access question responses in your server logic. Unlike directly accessing input$question_id, which only works for questions on the current page, all_data$question_id works for all questions by automatically restoring values from the database when needed.

Use all_data in conditional logic:

  sd_skip_if(
    all_data$age < 18 ~ "parental_consent",
    all_data$employed == "yes" ~ "employment_questions"
  )

Or in custom reactive expressions:

  output$custom_text <- renderText({
    paste("You selected:", all_data$favorite_color)
  })

The all_data list automatically stays synchronized with question responses and includes restored values from previous sessions (via cookies or page refreshes), making it safe to use even when navigating backward or refreshing the page.

See also

Examples

if (interactive()) {
  library(surveydown)

  # Basic sd_server() usage in app.R:
  # library(surveydown)
  #
  # db <- sd_database(
  #   host   = "db.xxxx.supabase.co",
  #   dbname = "postgres",
  #   port   = "5432",
  #   user   = "postgres",
  #   table  = "my_survey"
  # )
  #
  # server <- function(input, output, session) {
  #   sd_server(db = db)
  # }
  #
  # shiny::shinyApp(ui = sd_ui(), server = server)

  # All settings are configured in survey.qmd YAML header:
  # ---
  # survey-settings:
  #   show-previous: true
  #   auto-scroll: true
  #   required:
  #     - age
  #     - name
  # ---

  # Using all_data for conditional logic:
  # server <- function(input, output, session) {
  #   sd_skip_if(
  #     all_data$age < 18 ~ "parental_consent",
  #     all_data$country == "USA" ~ "usa_specific"
  #   )
  #
  #   sd_server(db = db)
  # }

  # Find a working directory and start from a template:
  sd_create_survey(template = "default")
  # This creates survey.qmd and app.R - launch the survey using app.R
}