Files

<pl-question-panel>
  <p>
    This question embeds external links in its content so that LockDown
    Browser's content-link behavior can be exercised. PrairieLearn is opened
    in a stemmed (rldbwn) child window with blocked navigation to outside
    sources, so clicking one of the links below should show
    <strong>"LINK IS BLOCKED"</strong> on the toolbar rather than navigating
    away.
  </p>

  <p>Try opening this YouTube video:</p>
  <ul>
    <li>
      <a href="https://www.youtube.com/watch?v=aircAruvnKk" target="_blank" rel="noopener">
        https://www.youtube.com/watch?v=aircAruvnKk
      </a>
    </li>
  </ul>
  <p>
    A couple of other external links, useful for confirming the same
    blocked-navigation behavior on different sites:
  </p>
  <ul>
    <li>
      <a href="https://en.wikipedia.org/wiki/Fibonacci_sequence" target="_blank" rel="noopener">
        https://en.wikipedia.org/wiki/Fibonacci_sequence
      </a>
    </li>
    <li>
      <a href="https://docs.prairielearn.com" target="_blank" rel="noopener">
        https://docs.prairielearn.com
      </a>
    </li>
  </ul>

  <p>The same YouTube video is also embedded directly in this page as an iframe:</p>
  <p>
    <iframe
      width="560"
      height="315"
      src="https://www.youtube.com/embed/aircAruvnKk"
      title="YouTube video player"
      frameborder="0"
      allowfullscreen
    ></iframe>
  </p>

  <p>Click one of the external links above. What happens?</p>
</pl-question-panel>

<pl-multiple-choice answers-name="link_behavior">
  <pl-answer correct="true">
    Navigation was blocked and the toolbar showed "LINK IS BLOCKED".
  </pl-answer>
  <pl-answer correct="false">
    The link opened in a new window and I could browse freely.
  </pl-answer>
  <pl-answer correct="false">
    The link opened in a new window, but only a single further navigation was
    allowed before being blocked.
  </pl-answer>
</pl-multiple-choice>