ttfb.njk

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 Copyright 2020 Google LLC
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     https://www.apache.org/licenses/LICENSE-2.0

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 See the License for the specific language governing permissions and
 limitations under the License.
-->
{% extends 'layout.njk' %}

{% block content %}
  <h1 elementtiming="main-heading">TTFB Test</h1>
  <p>
    <img elementtiming="main-image" {% if imgHidden %}hidden{% endif %} src="/test/img/square.png?delay={{ imgDelay }}">
  </p>

  <p>Text below the image</p>

  <p><a id="navigate-away" href="https://example.com">Navigate away</a></p>

  <script>
    // Set the blocking values based on query params if present.
    const params = new URLSearchParams(location.search);

    if (params.has('responseStart')) {
      const navEntry = performance.getEntriesByType('navigation')[0];
      Object.defineProperty(navEntry, 'responseStart', {
        value: Number(params.get('responseStart')),
      });
    }
  </script>

  <script type="module">
    const {onTTFB} = await __testImport('{{ modulePath }}');

    onTTFB((ttfb) => {
      // Log for easier manual testing.
      console.log(ttfb);

      // Test sending the metric to an analytics endpoint.
      navigator.sendBeacon(`/collect`, JSON.stringify(__toSafeObject(ttfb)));
    }, {reportAllChanges: self.__reportAllChanges});
  </script>
{% endblock %}