<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head>

<meta charset="utf-8">
<meta name="generator" content="quarto-1.5.56">

<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">

<meta name="author" content="Kyle Belanger">
<meta name="dcterms.date" content="2024-08-27">

<title>GenieFramework Microblog Part 1 – Kyle Belanger</title>
<style>
code{white-space: pre-wrap;}
span.smallcaps{font-variant: small-caps;}
div.columns{display: flex; gap: min(4vw, 1.5em);}
div.column{flex: auto; overflow-x: auto;}
div.hanging-indent{margin-left: 1.5em; text-indent: -1.5em;}
ul.task-list{list-style: none;}
ul.task-list li input[type="checkbox"] {
  width: 0.8em;
  margin: 0 0.8em 0.2em -1em; /* quarto-specific, see https://github.com/quarto-dev/quarto-cli/issues/4556 */ 
  vertical-align: middle;
}
/* CSS for syntax highlighting */
pre > code.sourceCode { white-space: pre; position: relative; }
pre > code.sourceCode > span { line-height: 1.25; }
pre > code.sourceCode > span:empty { height: 1.2em; }
.sourceCode { overflow: visible; }
code.sourceCode > span { color: inherit; text-decoration: inherit; }
div.sourceCode { margin: 1em 0; }
pre.sourceCode { margin: 0; }
@media screen {
div.sourceCode { overflow: auto; }
}
@media print {
pre > code.sourceCode { white-space: pre-wrap; }
pre > code.sourceCode > span { display: inline-block; text-indent: -5em; padding-left: 5em; }
}
pre.numberSource code
  { counter-reset: source-line 0; }
pre.numberSource code > span
  { position: relative; left: -4em; counter-increment: source-line; }
pre.numberSource code > span > a:first-child::before
  { content: counter(source-line);
    position: relative; left: -1em; text-align: right; vertical-align: baseline;
    border: none; display: inline-block;
    -webkit-touch-callout: none; -webkit-user-select: none;
    -khtml-user-select: none; -moz-user-select: none;
    -ms-user-select: none; user-select: none;
    padding: 0 4px; width: 4em;
  }
pre.numberSource { margin-left: 3em;  padding-left: 4px; }
div.sourceCode
  {   }
@media screen {
pre > code.sourceCode > span > a:first-child::before { text-decoration: underline; }
}
</style>


<script src="../../site_libs/quarto-nav/quarto-nav.js"></script>
<script src="../../site_libs/quarto-nav/headroom.min.js"></script>
<script src="../../site_libs/clipboard/clipboard.min.js"></script>
<script src="../../site_libs/quarto-search/autocomplete.umd.js"></script>
<script src="../../site_libs/quarto-search/fuse.min.js"></script>
<script src="../../site_libs/quarto-search/quarto-search.js"></script>
<meta name="quarto:offset" content="../../">
<script src="../../site_libs/quarto-html/quarto.js"></script>
<script src="../../site_libs/quarto-html/popper.min.js"></script>
<script src="../../site_libs/quarto-html/tippy.umd.min.js"></script>
<script src="../../site_libs/quarto-html/anchor.min.js"></script>
<link href="../../site_libs/quarto-html/tippy.css" rel="stylesheet">
<link href="../../site_libs/quarto-html/quarto-syntax-highlighting.css" rel="stylesheet" id="quarto-text-highlighting-styles">
<script src="../../site_libs/bootstrap/bootstrap.min.js"></script>
<link href="../../site_libs/bootstrap/bootstrap-icons.css" rel="stylesheet">
<link href="../../site_libs/bootstrap/bootstrap.min.css" rel="stylesheet" id="quarto-bootstrap" data-mode="light">
<script id="quarto-search-options" type="application/json">{
  "location": "navbar",
  "copy-button": false,
  "collapse-after": 3,
  "panel-placement": "end",
  "type": "overlay",
  "limit": 50,
  "keyboard-shortcut": [
    "f",
    "/",
    "s"
  ],
  "show-item-context": false,
  "language": {
    "search-no-results-text": "No results",
    "search-matching-documents-text": "matching documents",
    "search-copy-link-title": "Copy link to search",
    "search-hide-matches-text": "Hide additional matches",
    "search-more-match-text": "more match in this document",
    "search-more-matches-text": "more matches in this document",
    "search-clear-button-title": "Clear",
    "search-text-placeholder": "",
    "search-detached-cancel-button-title": "Cancel",
    "search-submit-button-title": "Submit",
    "search-label": "Search"
  }
}</script>
<meta name="quarto:status" content="draft">


<link rel="stylesheet" href="../../styles.css">
</head>

<body class="floating nav-fixed">

<div id="quarto-search-results"></div>
  <header id="quarto-header" class="headroom fixed-top quarto-banner"><div id="quarto-draft-alert" class="alert alert-warning"><i class="bi bi-pencil-square"></i>Draft</div>
    <nav class="navbar navbar-expand-lg " data-bs-theme="dark">
      <div class="navbar-container container-fluid">
      <div class="navbar-brand-container mx-auto">
    <a class="navbar-brand" href="../../index.html">
    <span class="navbar-title">Kyle Belanger</span>
    </a>
  </div>
            <div id="quarto-search" class="" title="Search"></div>
          <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarCollapse" aria-controls="navbarCollapse" role="menu" aria-expanded="false" aria-label="Toggle navigation" onclick="if (window.quartoToggleHeadroom) { window.quartoToggleHeadroom(); }">
  <span class="navbar-toggler-icon"></span>
</button>
          <div class="collapse navbar-collapse" id="navbarCollapse">
            <ul class="navbar-nav navbar-nav-scroll ms-auto">
  <li class="nav-item">
    <a class="nav-link" href="../../blog.html"> 
<span class="menu-text">Posts</span></a>
  </li>  
  <li class="nav-item">
    <a class="nav-link" href="../../kyle_resume.pdf"> 
<span class="menu-text">Resume</span></a>
  </li>  
  <li class="nav-item compact">
    <a class="nav-link" href="https://github.com/mmmmtoasty19"> <i class="bi bi-github" role="img">
</i> 
<span class="menu-text"></span></a>
  </li>  
</ul>
          </div> <!-- /navcollapse -->
            <div class="quarto-navbar-tools">
</div>
      </div> <!-- /container-fluid -->
    </nav>
</header>
<!-- content -->
<header id="title-block-header" class="quarto-title-block default toc-left page-columns page-full">
  <div class="quarto-title-banner page-columns page-full">
    <div class="quarto-title column-body">
      <h1 class="title">GenieFramework Microblog Part 1</h1>
                                <div class="quarto-categories">
                <div class="quarto-category">Julia</div>
                <div class="quarto-category">dataViz</div>
                <div class="quarto-category">GenieFramework</div>
              </div>
                  </div>
  </div>
    
  
  <div class="quarto-title-meta">

      <div>
      <div class="quarto-title-meta-heading">Author</div>
      <div class="quarto-title-meta-contents">
               <p><a href="https://kyleb.rbind.io/">Kyle Belanger</a> </p>
            </div>
    </div>
      
      <div>
      <div class="quarto-title-meta-heading">Published</div>
      <div class="quarto-title-meta-contents">
        <p class="date">August 27, 2024</p>
      </div>
    </div>
    
      
    </div>
    
  
  </header><div id="quarto-content" class="quarto-container page-columns page-rows-contents page-layout-article page-navbar">
<!-- sidebar -->
  <nav id="quarto-sidebar" class="sidebar collapse collapse-horizontal quarto-sidebar-collapse-item sidebar-navigation floating overflow-auto">
    <nav id="TOC" role="doc-toc" class="toc-active">
    <h2 id="toc-title">Table of contents</h2>
   
  <ul>
  <li><a href="#introduction" id="toc-introduction" class="nav-link active" data-scroll-target="#introduction">Introduction</a></li>
  <li><a href="#getting-started" id="toc-getting-started" class="nav-link" data-scroll-target="#getting-started">Getting Started</a></li>
  <li><a href="#creating-the-app" id="toc-creating-the-app" class="nav-link" data-scroll-target="#creating-the-app">Creating The App</a></li>
  <li><a href="#creating-a-hello-world-genie-app" id="toc-creating-a-hello-world-genie-app" class="nav-link" data-scroll-target="#creating-a-hello-world-genie-app">Creating a Hello World Genie App</a></li>
  </ul>
</nav>
</nav>
<div id="quarto-sidebar-glass" class="quarto-sidebar-collapse-item" data-bs-toggle="collapse" data-bs-target=".quarto-sidebar-collapse-item"></div>
<!-- margin-sidebar -->
    <div id="quarto-margin-sidebar" class="sidebar margin-sidebar zindex-bottom">
    </div>
<!-- main -->
<main class="content quarto-banner-title-block" id="quarto-document-content">





<section id="introduction" class="level2">
<h2 class="anchored" data-anchor-id="introduction">Introduction</h2>
<p>Quite some time ago I started attempting to learn python and web development. I claim in no way to be even close to an expert on either one of those things, in fact I am truly a beginner at both. While I never continued with python I have always enjoyed web development, creating quite a few small R Shiny apps along the way. As I have decided to learn Julia I am instantly drawn to Web Development, and I decided to try out the Genie Framework. While there exist some tutorials on the web, I find the all contain small pieces of information but lack putting everything together. Form my learning python days, I know that there exists a WONDERFUL tutorial for the python Flask framework (<a href="https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world">Found Here</a>). I decided to challenge myself and recreate his website using Genie, and the Model, View, Controller model. I will attempt to document what I do to try and help others along the way. As stated above I AM NOT AN EXPERT, so at any time there is a good chance I am not doing something the best way possible! I encourage everyone to follow along and make suggestions for improvements. I am going to try my best to go in the order Miguel did, but for some chapters I will skip sections or combine things as needed to make them work for the framework.</p>
</section>
<section id="getting-started" class="level2">
<h2 class="anchored" data-anchor-id="getting-started">Getting Started</h2>
<p>Miguel’s blog does a great job of going into installing python and flask as well as setting up virtual environments in python. I am going to skip most of this as there is great documentation out there on how to install Julia and set up a project (Genie will actually take care of this for us). Instead I will link here what I would say are the three prerequisites for getting started.</p>
<ul>
<li><a href="https://julialang.org/downloads/">Download and install Julia</a></li>
<li>The IDE of your choice (I use VSCode, and the <a href="https://marketplace.visualstudio.com/items?itemName=julialang.language-julia">Julia Extension</a>)</li>
<li>Add Genie to your Julia environment (see below)</li>
</ul>
<p>To add Genie to your Julia environment, open the Julia REPL and type the following:</p>
<div class="sourceCode" id="cb1"><pre class="sourceCode julia code-with-copy"><code class="sourceCode julia"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a>pkg<span class="op">&gt;</span> add Genie <span class="co"># press ] from julia&gt; prompt to enter Pkg mode</span></span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
</section>
<section id="creating-the-app" class="level2">
<h2 class="anchored" data-anchor-id="creating-the-app">Creating The App</h2>
<p>Genie will take care of creating a new directory for us, but we will want to open the Julia REPL from whatever directory we want the app folder to live in. Once that has been decided open a Julia REPL and type the following:</p>
<div class="sourceCode" id="cb2"><pre class="sourceCode julia code-with-copy"><code class="sourceCode julia"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a>julia<span class="op">&gt;</span> <span class="im">using</span> <span class="bu">Genie</span></span>
<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb2-3"><a href="#cb2-3" aria-hidden="true" tabindex="-1"></a>julia<span class="op">&gt;</span> Genie.Generator.<span class="fu">newapp</span>(<span class="st">"Microblog"</span>)</span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
<p>Upon executing the command, Genie will:</p>
<ul>
<li>make a new dir called <code>Microblog</code> and <code>cd()</code> into it,</li>
<li>install all the app’s dependencies</li>
<li>create a new Julia project (adding the Project.toml and Manifest.toml files),</li>
<li>activate the project,</li>
<li>automatically load the new app’s environment into the REPL,</li>
<li>start the web server on the default Genie port (port 8000) and host (127.0.0.1 – aka <code>localhost</code>).</li>
</ul>
<p>At this point you can confirm that everything worked as expected by visiting <a href="http://127.0.0.1:8000">http://127.0.0.1:8000</a> in your favorite web browser. You should see Genie’s welcome page. If at any point you want to exit the REPL and reload the app perform the following:</p>
<div class="sourceCode" id="cb3"><pre class="sourceCode julia code-with-copy"><code class="sourceCode julia"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a>julia<span class="op">&gt;</span> <span class="im">using</span> <span class="bu">Genie</span></span>
<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a>julia<span class="op">&gt;</span> Genie.<span class="fu">loadapp</span>()</span>
<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a>julia<span class="op">&gt;</span> <span class="fu">up</span>()</span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
<p>This will reload the app and activate the web server. You can again visit <a href="http://127.0.0.1:8000">http://127.0.0.1:8000</a> to test that everything is working.</p>
</section>
<section id="creating-a-hello-world-genie-app" class="level2">
<h2 class="anchored" data-anchor-id="creating-a-hello-world-genie-app">Creating a Hello World Genie App</h2>
<p>While Genie by default has a welcome page, lets change it to a simple Hello World page to make the app our own. Open routes.jl and change the “/” route to the following:</p>
<div class="code-with-filename">
<div class="code-with-filename-file">
<pre><strong>routes.jl</strong></pre>
</div>
<div class="sourceCode" id="cb4" data-filename="routes.jl"><pre class="sourceCode julia code-with-copy"><code class="sourceCode julia"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a><span class="fu">route</span>(<span class="st">"/"</span>) <span class="cf">do</span></span>
<span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a>  <span class="st">"Hello World!"</span></span>
<span id="cb4-3"><a href="#cb4-3" aria-hidden="true" tabindex="-1"></a><span class="cf">end</span></span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
</div>
<p>If we go to <a href="http://127.0.0.1:8000">http://127.0.0.1:8000</a> we should now see the following:</p>
<div class="quarto-figure quarto-figure-center">
<figure class="figure">
<p><img src="helloworldscreenshot.png" class="img-fluid figure-img"></p>
<figcaption>Hello World Screenshot</figcaption>
</figure>
</div>


</section>

<div id="quarto-appendix" class="default"><section class="quarto-appendix-contents" id="quarto-reuse"><h2 class="anchored quarto-appendix-heading">Reuse</h2><div class="quarto-appendix-contents"><div><a rel="license" href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a></div></div></section><section class="quarto-appendix-contents" id="quarto-citation"><h2 class="anchored quarto-appendix-heading">Citation</h2><div><div class="quarto-appendix-secondary-label">BibTeX citation:</div><pre class="sourceCode code-with-copy quarto-appendix-bibtex"><code class="sourceCode bibtex">@online{belanger2024,
  author = {Belanger, Kyle},
  title = {GenieFramework {Microblog} {Part} 1},
  date = {2024-08-27},
  langid = {en}
}
</code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre><div class="quarto-appendix-secondary-label">For attribution, please cite this work as:</div><div id="ref-belanger2024" class="csl-entry quarto-appendix-citeas" role="listitem">
Belanger, Kyle. 2024. <span>“GenieFramework Microblog Part 1.”</span>
August 27, 2024.
</div></div></section></div></main> <!-- /main -->
<script id="quarto-html-after-body" type="application/javascript">
window.document.addEventListener("DOMContentLoaded", function (event) {
  const toggleBodyColorMode = (bsSheetEl) => {
    const mode = bsSheetEl.getAttribute("data-mode");
    const bodyEl = window.document.querySelector("body");
    if (mode === "dark") {
      bodyEl.classList.add("quarto-dark");
      bodyEl.classList.remove("quarto-light");
    } else {
      bodyEl.classList.add("quarto-light");
      bodyEl.classList.remove("quarto-dark");
    }
  }
  const toggleBodyColorPrimary = () => {
    const bsSheetEl = window.document.querySelector("link#quarto-bootstrap");
    if (bsSheetEl) {
      toggleBodyColorMode(bsSheetEl);
    }
  }
  toggleBodyColorPrimary();  
  const icon = "";
  const anchorJS = new window.AnchorJS();
  anchorJS.options = {
    placement: 'right',
    icon: icon
  };
  anchorJS.add('.anchored');
  const isCodeAnnotation = (el) => {
    for (const clz of el.classList) {
      if (clz.startsWith('code-annotation-')) {                     
        return true;
      }
    }
    return false;
  }
  const onCopySuccess = function(e) {
    // button target
    const button = e.trigger;
    // don't keep focus
    button.blur();
    // flash "checked"
    button.classList.add('code-copy-button-checked');
    var currentTitle = button.getAttribute("title");
    button.setAttribute("title", "Copied!");
    let tooltip;
    if (window.bootstrap) {
      button.setAttribute("data-bs-toggle", "tooltip");
      button.setAttribute("data-bs-placement", "left");
      button.setAttribute("data-bs-title", "Copied!");
      tooltip = new bootstrap.Tooltip(button, 
        { trigger: "manual", 
          customClass: "code-copy-button-tooltip",
          offset: [0, -8]});
      tooltip.show();    
    }
    setTimeout(function() {
      if (tooltip) {
        tooltip.hide();
        button.removeAttribute("data-bs-title");
        button.removeAttribute("data-bs-toggle");
        button.removeAttribute("data-bs-placement");
      }
      button.setAttribute("title", currentTitle);
      button.classList.remove('code-copy-button-checked');
    }, 1000);
    // clear code selection
    e.clearSelection();
  }
  const getTextToCopy = function(trigger) {
      const codeEl = trigger.previousElementSibling.cloneNode(true);
      for (const childEl of codeEl.children) {
        if (isCodeAnnotation(childEl)) {
          childEl.remove();
        }
      }
      return codeEl.innerText;
  }
  const clipboard = new window.ClipboardJS('.code-copy-button:not([data-in-quarto-modal])', {
    text: getTextToCopy
  });
  clipboard.on('success', onCopySuccess);
  if (window.document.getElementById('quarto-embedded-source-code-modal')) {
    // For code content inside modals, clipBoardJS needs to be initialized with a container option
    // TODO: Check when it could be a function (https://github.com/zenorocha/clipboard.js/issues/860)
    const clipboardModal = new window.ClipboardJS('.code-copy-button[data-in-quarto-modal]', {
      text: getTextToCopy,
      container: window.document.getElementById('quarto-embedded-source-code-modal')
    });
    clipboardModal.on('success', onCopySuccess);
  }
    var localhostRegex = new RegExp(/^(?:http|https):\/\/localhost\:?[0-9]*\//);
    var mailtoRegex = new RegExp(/^mailto:/);
      var filterRegex = new RegExp('/' + window.location.host + '/');
    var isInternal = (href) => {
        return filterRegex.test(href) || localhostRegex.test(href) || mailtoRegex.test(href);
    }
    // Inspect non-navigation links and adorn them if external
 	var links = window.document.querySelectorAll('a[href]:not(.nav-link):not(.navbar-brand):not(.toc-action):not(.sidebar-link):not(.sidebar-item-toggle):not(.pagination-link):not(.no-external):not([aria-hidden]):not(.dropdown-item):not(.quarto-navigation-tool):not(.about-link)');
    for (var i=0; i<links.length; i++) {
      const link = links[i];
      if (!isInternal(link.href)) {
        // undo the damage that might have been done by quarto-nav.js in the case of
        // links that we want to consider external
        if (link.dataset.originalHref !== undefined) {
          link.href = link.dataset.originalHref;
        }
      }
    }
  function tippyHover(el, contentFn, onTriggerFn, onUntriggerFn) {
    const config = {
      allowHTML: true,
      maxWidth: 500,
      delay: 100,
      arrow: false,
      appendTo: function(el) {
          return el.parentElement;
      },
      interactive: true,
      interactiveBorder: 10,
      theme: 'quarto',
      placement: 'bottom-start',
    };
    if (contentFn) {
      config.content = contentFn;
    }
    if (onTriggerFn) {
      config.onTrigger = onTriggerFn;
    }
    if (onUntriggerFn) {
      config.onUntrigger = onUntriggerFn;
    }
    window.tippy(el, config); 
  }
  const noterefs = window.document.querySelectorAll('a[role="doc-noteref"]');
  for (var i=0; i<noterefs.length; i++) {
    const ref = noterefs[i];
    tippyHover(ref, function() {
      // use id or data attribute instead here
      let href = ref.getAttribute('data-footnote-href') || ref.getAttribute('href');
      try { href = new URL(href).hash; } catch {}
      const id = href.replace(/^#\/?/, "");
      const note = window.document.getElementById(id);
      if (note) {
        return note.innerHTML;
      } else {
        return "";
      }
    });
  }
  const xrefs = window.document.querySelectorAll('a.quarto-xref');
  const processXRef = (id, note) => {
    // Strip column container classes
    const stripColumnClz = (el) => {
      el.classList.remove("page-full", "page-columns");
      if (el.children) {
        for (const child of el.children) {
          stripColumnClz(child);
        }
      }
    }
    stripColumnClz(note)
    if (id === null || id.startsWith('sec-')) {
      // Special case sections, only their first couple elements
      const container = document.createElement("div");
      if (note.children && note.children.length > 2) {
        container.appendChild(note.children[0].cloneNode(true));
        for (let i = 1; i < note.children.length; i++) {
          const child = note.children[i];
          if (child.tagName === "P" && child.innerText === "") {
            continue;
          } else {
            container.appendChild(child.cloneNode(true));
            break;
          }
        }
        if (window.Quarto?.typesetMath) {
          window.Quarto.typesetMath(container);
        }
        return container.innerHTML
      } else {
        if (window.Quarto?.typesetMath) {
          window.Quarto.typesetMath(note);
        }
        return note.innerHTML;
      }
    } else {
      // Remove any anchor links if they are present
      const anchorLink = note.querySelector('a.anchorjs-link');
      if (anchorLink) {
        anchorLink.remove();
      }
      if (window.Quarto?.typesetMath) {
        window.Quarto.typesetMath(note);
      }
      // TODO in 1.5, we should make sure this works without a callout special case
      if (note.classList.contains("callout")) {
        return note.outerHTML;
      } else {
        return note.innerHTML;
      }
    }
  }
  for (var i=0; i<xrefs.length; i++) {
    const xref = xrefs[i];
    tippyHover(xref, undefined, function(instance) {
      instance.disable();
      let url = xref.getAttribute('href');
      let hash = undefined; 
      if (url.startsWith('#')) {
        hash = url;
      } else {
        try { hash = new URL(url).hash; } catch {}
      }
      if (hash) {
        const id = hash.replace(/^#\/?/, "");
        const note = window.document.getElementById(id);
        if (note !== null) {
          try {
            const html = processXRef(id, note.cloneNode(true));
            instance.setContent(html);
          } finally {
            instance.enable();
            instance.show();
          }
        } else {
          // See if we can fetch this
          fetch(url.split('#')[0])
          .then(res => res.text())
          .then(html => {
            const parser = new DOMParser();
            const htmlDoc = parser.parseFromString(html, "text/html");
            const note = htmlDoc.getElementById(id);
            if (note !== null) {
              const html = processXRef(id, note);
              instance.setContent(html);
            } 
          }).finally(() => {
            instance.enable();
            instance.show();
          });
        }
      } else {
        // See if we can fetch a full url (with no hash to target)
        // This is a special case and we should probably do some content thinning / targeting
        fetch(url)
        .then(res => res.text())
        .then(html => {
          const parser = new DOMParser();
          const htmlDoc = parser.parseFromString(html, "text/html");
          const note = htmlDoc.querySelector('main.content');
          if (note !== null) {
            // This should only happen for chapter cross references
            // (since there is no id in the URL)
            // remove the first header
            if (note.children.length > 0 && note.children[0].tagName === "HEADER") {
              note.children[0].remove();
            }
            const html = processXRef(null, note);
            instance.setContent(html);
          } 
        }).finally(() => {
          instance.enable();
          instance.show();
        });
      }
    }, function(instance) {
    });
  }
      let selectedAnnoteEl;
      const selectorForAnnotation = ( cell, annotation) => {
        let cellAttr = 'data-code-cell="' + cell + '"';
        let lineAttr = 'data-code-annotation="' +  annotation + '"';
        const selector = 'span[' + cellAttr + '][' + lineAttr + ']';
        return selector;
      }
      const selectCodeLines = (annoteEl) => {
        const doc = window.document;
        const targetCell = annoteEl.getAttribute("data-target-cell");
        const targetAnnotation = annoteEl.getAttribute("data-target-annotation");
        const annoteSpan = window.document.querySelector(selectorForAnnotation(targetCell, targetAnnotation));
        const lines = annoteSpan.getAttribute("data-code-lines").split(",");
        const lineIds = lines.map((line) => {
          return targetCell + "-" + line;
        })
        let top = null;
        let height = null;
        let parent = null;
        if (lineIds.length > 0) {
            //compute the position of the single el (top and bottom and make a div)
            const el = window.document.getElementById(lineIds[0]);
            top = el.offsetTop;
            height = el.offsetHeight;
            parent = el.parentElement.parentElement;
          if (lineIds.length > 1) {
            const lastEl = window.document.getElementById(lineIds[lineIds.length - 1]);
            const bottom = lastEl.offsetTop + lastEl.offsetHeight;
            height = bottom - top;
          }
          if (top !== null && height !== null && parent !== null) {
            // cook up a div (if necessary) and position it 
            let div = window.document.getElementById("code-annotation-line-highlight");
            if (div === null) {
              div = window.document.createElement("div");
              div.setAttribute("id", "code-annotation-line-highlight");
              div.style.position = 'absolute';
              parent.appendChild(div);
            }
            div.style.top = top - 2 + "px";
            div.style.height = height + 4 + "px";
            div.style.left = 0;
            let gutterDiv = window.document.getElementById("code-annotation-line-highlight-gutter");
            if (gutterDiv === null) {
              gutterDiv = window.document.createElement("div");
              gutterDiv.setAttribute("id", "code-annotation-line-highlight-gutter");
              gutterDiv.style.position = 'absolute';
              const codeCell = window.document.getElementById(targetCell);
              const gutter = codeCell.querySelector('.code-annotation-gutter');
              gutter.appendChild(gutterDiv);
            }
            gutterDiv.style.top = top - 2 + "px";
            gutterDiv.style.height = height + 4 + "px";
          }
          selectedAnnoteEl = annoteEl;
        }
      };
      const unselectCodeLines = () => {
        const elementsIds = ["code-annotation-line-highlight", "code-annotation-line-highlight-gutter"];
        elementsIds.forEach((elId) => {
          const div = window.document.getElementById(elId);
          if (div) {
            div.remove();
          }
        });
        selectedAnnoteEl = undefined;
      };
        // Handle positioning of the toggle
    window.addEventListener(
      "resize",
      throttle(() => {
        elRect = undefined;
        if (selectedAnnoteEl) {
          selectCodeLines(selectedAnnoteEl);
        }
      }, 10)
    );
    function throttle(fn, ms) {
    let throttle = false;
    let timer;
      return (...args) => {
        if(!throttle) { // first call gets through
            fn.apply(this, args);
            throttle = true;
        } else { // all the others get throttled
            if(timer) clearTimeout(timer); // cancel #2
            timer = setTimeout(() => {
              fn.apply(this, args);
              timer = throttle = false;
            }, ms);
        }
      };
    }
      // Attach click handler to the DT
      const annoteDls = window.document.querySelectorAll('dt[data-target-cell]');
      for (const annoteDlNode of annoteDls) {
        annoteDlNode.addEventListener('click', (event) => {
          const clickedEl = event.target;
          if (clickedEl !== selectedAnnoteEl) {
            unselectCodeLines();
            const activeEl = window.document.querySelector('dt[data-target-cell].code-annotation-active');
            if (activeEl) {
              activeEl.classList.remove('code-annotation-active');
            }
            selectCodeLines(clickedEl);
            clickedEl.classList.add('code-annotation-active');
          } else {
            // Unselect the line
            unselectCodeLines();
            clickedEl.classList.remove('code-annotation-active');
          }
        });
      }
  const findCites = (el) => {
    const parentEl = el.parentElement;
    if (parentEl) {
      const cites = parentEl.dataset.cites;
      if (cites) {
        return {
          el,
          cites: cites.split(' ')
        };
      } else {
        return findCites(el.parentElement)
      }
    } else {
      return undefined;
    }
  };
  var bibliorefs = window.document.querySelectorAll('a[role="doc-biblioref"]');
  for (var i=0; i<bibliorefs.length; i++) {
    const ref = bibliorefs[i];
    const citeInfo = findCites(ref);
    if (citeInfo) {
      tippyHover(citeInfo.el, function() {
        var popup = window.document.createElement('div');
        citeInfo.cites.forEach(function(cite) {
          var citeDiv = window.document.createElement('div');
          citeDiv.classList.add('hanging-indent');
          citeDiv.classList.add('csl-entry');
          var biblioDiv = window.document.getElementById('ref-' + cite);
          if (biblioDiv) {
            citeDiv.innerHTML = biblioDiv.innerHTML;
          }
          popup.appendChild(citeDiv);
        });
        return popup.innerHTML;
      });
    }
  }
});
</script>
</div> <!-- /content -->




</body></html>