New "side-menus" component.

Based on the `modals` component.

See example at http://michaelrienstra.com/temporary/ratchet/side-menus.html

The current implementation relies on putting a wrapper (`<div class="side-menu-siblings-wrapper">`) around the `side-menu`s siblings (`<header class="bar">` & `<div class="content">`). I have working code to handle the wrapping of siblings automatically, as well as working code that works without the wrapper (but I realized I was going to have to add more "moving bits" to get the subtle drop shadow to animate without the wrapper).

Minimally tested on Android (Nexus 4) & iOS (iPhone 5).

Happy to do more testing / etc. if this component is of interest.

Attribution: I borrowed a few lines of CSS from http://mmenu.frebsite.nl/ (which is dual licensed under the MIT and GPL licenses).

js/side-menus.js

@@ -0,0 +1,74 @@
+/* ========================================================================
+ * Ratchet: side-menus.js v2.0.2
+ * http://goratchet.com/components#sideMenus
+ * ========================================================================
+ * Copyright 2014 Connor Sears
+ * Licensed under MIT (https://github.com/twbs/ratchet/blob/master/LICENSE)
+ * ======================================================================== */
+
+!(function () {
+  'use strict';
+
+  var findSideMenus = function (target) {
+    var i;
+    var sideMenus = document.querySelectorAll('a');
+
+    for (; target && target !== document; target = target.parentNode) {
+      for (i = sideMenus.length; i--;) {
+        if (sideMenus[i] === target) {
+          return target;
+        }
+      }
+    }
+  };
+
+  var getSideMenu = function (event) {
+    var sideMenuToggle = findSideMenus(event.target);
+    if (sideMenuToggle && sideMenuToggle.hash) {
+      var sideMenu = document.querySelector(sideMenuToggle.hash);
+      if (sideMenu && sideMenu.classList.contains('side-menu')) {
+        return sideMenu;
+      }
+    }
+  };
+
+  var getSideMenuSiblings = function (sideMenu) {
+    var siblings = [].slice.call(sideMenu.parentNode.children);
+    siblings = siblings.filter(function(val) {
+      return [sideMenu].indexOf(val) === -1 && val.nodeName !== 'SCRIPT';
+    });
+    return siblings;
+  };
+
+  window.addEventListener('touchend', function (event) {
+    var sideMenu = getSideMenu(event);
+    if (sideMenu) {
+      var siblings = getSideMenuSiblings(sideMenu);
+      var i;
+      var l;
+      var hasBlocker = false;
+      for (i = 0, l = siblings.length; i < l; i++) {
+        if (!hasBlocker && siblings[i].classList.contains('side-menu-blocker')) {
+          hasBlocker = true;
+        }
+        if (siblings[i].classList.contains('activeSideMenu')) {
+          siblings[i].classList.remove('activeSideMenu');
+          siblings[i].classList.add('inactiveSideMenu');
+        } else {
+          siblings[i].classList.remove('inactiveSideMenu');
+          siblings[i].classList.add('activeSideMenu');
+        }
+      }
+      if (hasBlocker === false) {
+        var blocker = document.createElement('a');
+        blocker.href = '#' + sideMenu.id;
+        blocker.classList.add('side-menu-blocker');
+        sideMenu.parentElement.appendChild(blocker);
+        siblings.push(blocker);
+        blocker.classList.add('activeSideMenu');
+      }
+
+      event.preventDefault(); // prevents rewriting url (apps can still use hash values in url)
+    }
+  });
+}());

sass/side-menus.scss

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+//
+// Side menus
+// --------------------------------------------------
+
+.side-menu {
+  position: fixed;
+  top: 0;
+  z-index: -1;
+  width: 80%;
+  height: 100%;
+}
+
+.side-menu-blocker {
+  background: url(data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==) transparent;
+  display: none;
+  width: 100%;
+  height: 100%;
+  position: fixed;
+  top: 0;
+  z-index: 999999;
+
+  &.activeSideMenu {
+    display: block;
+    box-shadow: none;
+  }
+}
+
+.side-menu-siblings-wrapper {
+  width: 100%;
+  height: 100%;
+  /* Alternate approach, as per BODY:
+      position: fixed;
+      top: 0;
+      right: 0;
+      bottom: 0;
+      left: 0;
+  */
+}
+
+.inactiveSideMenu, .activeSideMenu {
+  box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
+  -webkit-transition: -webkit-transform .4s;
+     -moz-transition: -moz-transform .4s;
+          transition: transform .4s;
+  @include transform(translate3d(0, 0, 0));
+}
+.activeSideMenu {
+  @include transform(translate3d(80%, 0, 0));
+}