Shiny module server for an embedded survey

Draws the survey and collects the respondent's answers. Returns a reactive holding NULL until the survey has been submitted and saved.

Usage

survey_module_server(id, instrument, on_submit = NULL)

Arguments

id: A character string matching the id passed to survey_module_ui().
instrument: An sframe object, or a reactive that returns one.
on_submit: Optional function of one argument, called with the response list before the survey is marked complete. Use it to store the response. An error it raises is shown to the respondent, and the survey stays open for another attempt.

Value

A reactive that returns NULL until a response is submitted and on_submit, when supplied, has returned. After that it returns the response list.

Supported item types

Every item type is supported, with the same controls render_survey() uses: likert, single choice, multiple choice, numeric, text, text area, date, slider, rating, ranking, matrix, pairwise comparison and criteria weight, plus section breaks and text blocks.

What is submitted

The response is a named list. It starts with response_id, started_at and submitted_at, followed by one element per response column, named as read_responses() expects. A multi-column item contributes one element per column: item__row for a matrix, item__option for ranking and multiple choice, and one element per pair or criterion for decision items. Values are character.

An item hidden by branching is NA, so an answer given before branching hid its item is never submitted. An unanswered item is NA too. A slider counts as answered once the respondent moves it, and a ranking once the respondent reorders it or chooses "Keep this order". Date questions start empty.

Saving, and a failed save

on_submit is called with the response before the survey is marked complete. If it raises an error, the respondent sees a message and stays on the last page, can submit again, and the returned reactive stays NULL. The thank-you screen appears only after on_submit returns.

Changing the instrument

When instrument is a reactive and its value changes, the survey returns to the welcome screen, the returned reactive goes back to NULL, and no answer given to the previous instrument carries into the new one.

Examples

# \donttest{
# survey_module_ui() has a complete example, including on_submit.
# }