added a javascript build pipeline for transpiling and minifying; updated readme

javascript/.babelrc

@@ -0,0 +1,3 @@
+{
+    "presets": ["@babel/preset-env"]
+}

javascript/package.json

@@ -0,0 +1,9 @@
+{
+  "devDependencies": {
+    "@babel/core": "^7.4.4",
+    "@babel/preset-env": "^7.4.4",
+    "babel-loader": "^8.0.5",
+    "webpack": "^4.30.0",
+    "webpack-cli": "^3.3.2"
+  }
+}

javascript/src/zulma_navbar.js

@@ -0,0 +1,8 @@
+(function () {
+    var burger = document.querySelector('.burger');
+    var menu = document.querySelector('#' + burger.dataset.target);
+    burger.addEventListener('click', function () {
+        burger.classList.toggle('is-active');
+        menu.classList.toggle('is-active');
+    });
+})();

javascript/src/zulma_search.js

@@ -0,0 +1,184 @@
+function debounce(func, wait) {
+  var timeout;
+
+  return function () {
+    var context = this;
+    var args = arguments;
+    clearTimeout(timeout);
+
+    timeout = setTimeout(function () {
+      timeout = null;
+      func.apply(context, args);
+    }, wait);
+  };
+}
+
+// Taken from mdbook
+// The strategy is as follows:
+// First, assign a value to each word in the document:
+//  Words that correspond to search terms (stemmer aware): 40
+//  Normal words: 2
+//  First word in a sentence: 8
+// Then use a sliding window with a constant number of words and count the
+// sum of the values of the words within the window. Then use the window that got the
+// maximum sum. If there are multiple maximas, then get the last one.
+// Enclose the terms in <b>.
+function makeTeaser(body, terms) {
+  var TERM_WEIGHT = 40;
+  var NORMAL_WORD_WEIGHT = 2;
+  var FIRST_WORD_WEIGHT = 8;
+  var TEASER_MAX_WORDS = 30;
+
+  var stemmedTerms = terms.map(function (w) {
+    return elasticlunr.stemmer(w.toLowerCase());
+  });
+  var termFound = false;
+  var index = 0;
+  var weighted = []; // contains elements of ["word", weight, index_in_document]
+
+  // split in sentences, then words
+  var sentences = body.toLowerCase().split(". ");
+
+  for (var i in sentences) {
+    var words = sentences[i].split(" ");
+    var value = FIRST_WORD_WEIGHT;
+
+    for (var j in words) {
+      var word = words[j];
+
+      if (word.length > 0) {
+        for (var k in stemmedTerms) {
+          if (elasticlunr.stemmer(word).startsWith(stemmedTerms[k])) {
+            value = TERM_WEIGHT;
+            termFound = true;
+          }
+        }
+        weighted.push([word, value, index]);
+        value = NORMAL_WORD_WEIGHT;
+      }
+
+      index += word.length;
+      index += 1; // ' ' or '.' if last word in sentence
+    }
+
+    index += 1; // because we split at a two-char boundary '. '
+  }
+
+  if (weighted.length === 0) {
+    return body;
+  }
+
+  var windowWeights = [];
+  var windowSize = Math.min(weighted.length, TEASER_MAX_WORDS);
+  // We add a window with all the weights first
+  var curSum = 0;
+  for (var i = 0; i < windowSize; i++) {
+    curSum += weighted[i][1];
+  }
+  windowWeights.push(curSum);
+
+  for (var i = 0; i < weighted.length - windowSize; i++) {
+    curSum -= weighted[i][1];
+    curSum += weighted[i + windowSize][1];
+    windowWeights.push(curSum);
+  }
+
+  // If we didn't find the term, just pick the first window
+  var maxSumIndex = 0;
+  if (termFound) {
+    var maxFound = 0;
+    // backwards
+    for (var i = windowWeights.length - 1; i >= 0; i--) {
+      if (windowWeights[i] > maxFound) {
+        maxFound = windowWeights[i];
+        maxSumIndex = i;
+      }
+    }
+  }
+
+  var teaser = [];
+  var startIndex = weighted[maxSumIndex][2];
+  for (var i = maxSumIndex; i < maxSumIndex + windowSize; i++) {
+    var word = weighted[i];
+    if (startIndex < word[2]) {
+      // missing text from index to start of `word`
+      teaser.push(body.substring(startIndex, word[2]));
+      startIndex = word[2];
+    }
+
+    // add <em/> around search terms
+    if (word[1] === TERM_WEIGHT) {
+      teaser.push("<b>");
+    }
+    startIndex = word[2] + word[0].length;
+    teaser.push(body.substring(word[2], startIndex));
+
+    if (word[1] === TERM_WEIGHT) {
+      teaser.push("</b>");
+    }
+  }
+  teaser.push("…");
+  return teaser.join("");
+}
+
+function formatSearchResultItem(item, terms) {
+  return '<div class="search-results__item box">' +
+    `<a href="${item.ref}">${item.doc.title}</a>` +
+    `<div>${makeTeaser(item.doc.body, terms)}</div>` +
+    '</div>';
+}
+
+function initSearch() {
+  var $searchInput = document.getElementById("search");
+  var $searchResults = document.querySelector(".search-results");
+  var $searchResultsItems = document.querySelector(".search-results__items");
+  var MAX_ITEMS = 10;
+
+  var options = {
+    bool: "AND",
+    fields: {
+      title: {
+        boost: 2
+      },
+      body: {
+        boost: 1
+      },
+    }
+  };
+  var currentTerm = "";
+  var index = elasticlunr.Index.load(window.searchIndex);
+
+  $searchInput.addEventListener("keyup", debounce(function () {
+    var term = $searchInput.value.trim();
+    if (!index) {
+      return;
+    }
+    $searchResults.style.display = term === "" ? "none" : "block";
+    $searchResultsItems.innerHTML = "";
+    if (term === "") {
+      return;
+    }
+
+    var results = index.search(term, options);
+    if (results.length === 0) {
+      $searchResults.style.display = "none";
+      return;
+    }
+
+    currentTerm = term;
+    for (var i = 0; i < Math.min(results.length, MAX_ITEMS); i++) {
+      var item = document.createElement("li");
+      item.innerHTML = formatSearchResultItem(results[i], term.split(" "));
+      $searchResultsItems.appendChild(item);
+    }
+  }, 150));
+}
+
+
+if (document.readyState === "complete" ||
+  (document.readyState !== "loading" && !document.documentElement.doScroll)
+) {
+  initSearch();
+} else {
+  document.addEventListener("DOMContentLoaded", initSearch);
+}

javascript/src/zulma_switchcss.js

@@ -0,0 +1,105 @@
+(function (switch_css) {
+    //Constants
+    const THEME_KEY = "ZULMA_THEME";
+    const STOP_BLINK_CSS_ID = "stop-blink";
+    const STYLESHEET_CLASSNAME = "stylesheet"
+
+    //Variables
+    let link = null;
+    let theme = localStorage.getItem(THEME_KEY);
+
+    //Private Methods
+    /* Called when the theme is changed */
+    function changeTheme(themeName, firstLoad) {
+        //create the css link element
+        var fileref = document.createElement("link");
+        fileref.rel = "stylesheet";
+        fileref.type = "text/css";
+        fileref.href = `/${themeName}.css`;
+
+        //append it to the head
+        link = document.getElementsByTagName("head")[0].appendChild(fileref);
+
+        //when it's loaded, call onLinkLoad
+        link.addEventListener('load', onLinkLoad);
+
+        //if this is the first load of the page, remove the current stylesheet early to avoid flash of wrongly styled content
+        if (firstLoad) {
+            removeStylesheets();
+        }
+
+        saveTheme(themeName);
+    };
+
+    function removeStylesheets() {
+        document.querySelectorAll(`.${STYLESHEET_CLASSNAME}`).forEach((el) => {
+            el.remove();
+        });
+    }
+
+    /* The function called when the css has finished loading */
+    function onLinkLoad() {
+        link.removeEventListener('load', onLinkLoad);
+        //remove the previous stylesheet(s)
+        removeStylesheets();
+        //add stylesheet class
+        link.className += STYLESHEET_CLASSNAME;
+        //make body visible again if it was hidden
+        showBody();
+    };
+
+    /* Saves the current theme in localstorage */
+    function saveTheme(themeName) {
+        localStorage.setItem(THEME_KEY, themeName);
+    };
+
+    /* Hides the body of the page */
+    function hideBody() {
+        var head = document.getElementsByTagName('head')[0];
+        var style = document.createElement('style');
+
+        style.id = STOP_BLINK_CSS_ID;
+        style.setAttribute('type', 'text/css');
+
+        if (style.styleSheet) {
+            style.styleSheet.cssText = css;
+        } else {
+            style.appendChild(document.createTextNode('body{visibility:hidden;}'));
+        }
+        head.appendChild(style);
+    };
+
+    /* Shows the body of the page */
+    function showBody() {
+        let css = document.getElementById(STOP_BLINK_CSS_ID);
+        if (css)
+            css.remove();
+    };
+
+    //Public Methods
+    switch_css.init = function () {
+        //if user has selected and theme and it is not the current theme
+        if (theme && !document.getElementById(theme)) {
+            //hide the body to stop FOUC
+            hideBody();
+            //change the theme
+            changeTheme(theme, true);
+            //when the DOM is loaded, change the select to their current choice
+            window.addEventListener('DOMContentLoaded', () => {
+                document.querySelectorAll('#theme-select>option').forEach(element => {
+                    if (element.value === theme) {
+                        element.selected = 'selected';
+                    }
+                });
+            });
+        }
+        //when the DOM is loaded, set the dropdown to trigger the theme change
+        window.addEventListener('DOMContentLoaded', () => {
+            document.getElementById('theme-select').onchange = function () {
+                changeTheme(this.value);
+            }
+        });
+    }
+}(switch_css = window.switch_css || {}));
+
+switch_css.init();

javascript/webpack.config.js

@@ -0,0 +1,28 @@
+const path = require('path');
+
+module.exports = {
+    entry: {
+        zulma_navbar: './src/zulma_navbar.js',
+        zulma_search: './src/zulma_search.js',
+        zulma_switchcss: './src/zulma_switchcss.js'
+    },
+    output: {
+        filename: '[name].js',
+        path: path.resolve('../static/js')
+    },
+    module: {
+        rules: [{
+            test: /\.js$/,
+            exclude: /node_modules/,
+            use: ['babel-loader']
+        }]
+    },
+    resolve: {
+        extensions: ['*', '.js']
+    },
+    stats: {
+        colors: true
+    },
+    devtool: 'source-map',
+    mode: 'production',
+};