Add a "download my answers" button

Adds a button that, when clicked, gathers every question() and student_info() answer currently on the page – each already saved to the browser's localStorage as the reader worked through the tutorial – into a single readable JSON file and downloads it. This happens entirely in the reader's browser; there is no server to submit to, so this is meant for a reader to save and turn in themselves (e.g. attach to an email or upload to an LMS).

Usage

download_answers_button(
  filename_prefix = "learnr2-answers",
  label = "Download My Answers"
)

Arguments

filename_prefix

Prefix for the downloaded file's name. Defaults to "learnr2-answers".

label

Button label. Defaults to "Download My Answers".

Value

A learnr2_download_button object, printed as an interactive HTML button.

Details

The download's answers array is one flat list: every question() plus every {webr} code exercise, each as a { id, answer } pair keyed by the widget's (or exercise's) stable id. A question never submitted has answer: null; a choice question's answer is an array of the picked options; an image-paste reflection's answer is the pasted screenshot as a PNG data-URL string.

A {webr} exercise appears only under the condition quarto-live itself requires to keep a record of the reader's code at all: #| persist: true (already the convention every bundled tutorial follows). An exercise without persist: true has no saved copy of the reader's code anywhere – learnr2 included – so it can't appear in the download; this is a structural limit of quarto-live's own editor, not something download_answers_button() chooses to skip.

The download also carries a metadata block (timezone, browser info, and a random per-device id persisted across the reader's visits) and a time field: the moment the reader clicked "Download", lightly obfuscated so the raw timestamp isn't readable or hand-editable in the file. Recover it with submission_time(). Nothing else is hashed or signed – a determined reader can still edit their answers; this only keeps the submission time honest at a glance.

Examples

download_answers_button()