From a5e6ae6afc6d8b9a8d91d70941a991c7d25e97d1 Mon Sep 17 00:00:00 2001
From: Franz Liedke <franz@develophp.org>
Date: Wed, 15 Feb 2017 22:49:54 +0100
Subject: [PATCH 1/2] Affix sidebar when window is resized

Fixes #866.
---
 .../core/js/forum/src/utils/affixSidebar.js   | 42 +++++++++++++------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/framework/core/js/forum/src/utils/affixSidebar.js b/framework/core/js/forum/src/utils/affixSidebar.js
index 0acacbb5f..6d062d7b0 100644
--- a/framework/core/js/forum/src/utils/affixSidebar.js
+++ b/framework/core/js/forum/src/utils/affixSidebar.js
@@ -4,22 +4,38 @@
  *
  * @param {DOMElement} element
  * @param {Boolean} isInitialized
+ * @param {Object} context
  */
-export default function affixSidebar(element, isInitialized) {
+export default function affixSidebar(element, isInitialized, context) {
   if (isInitialized) return;
 
-  const $sidebar = $(element);
-  const $header = $('#header');
-  const $footer = $('#footer');
+  const onresize = () => {
+    const $sidebar = $(element);
+    const $header = $('#header');
+    const $footer = $('#footer');
+    const $affixElement = $sidebar.find('> ul');
 
-  // Don't affix the sidebar if it is taller than the viewport (otherwise
-  // there would be no way to scroll through its content).
-  if ($sidebar.outerHeight(true) > $(window).height() - $header.outerHeight(true)) return;
+    $(window).off('.affix');
+    $affixElement
+      .removeClass('affix affix-top affix-bottom')
+      .removeData('bs.affix');
 
-  $sidebar.find('> ul').affix({
-    offset: {
-      top: () => $sidebar.offset().top - $header.outerHeight(true) - parseInt($sidebar.css('margin-top'), 10),
-      bottom: () => this.bottom = $footer.outerHeight(true)
-    }
-  });
+    // Don't affix the sidebar if it is taller than the viewport (otherwise
+    // there would be no way to scroll through its content).
+    if ($sidebar.outerHeight(true) > $(window).height() - $header.outerHeight(true)) return;
+
+    $affixElement.affix({
+      offset: {
+        top: () => $sidebar.offset().top - $header.outerHeight(true) - parseInt($sidebar.css('margin-top'), 10),
+        bottom: () => this.bottom = $footer.outerHeight(true)
+      }
+    });
+  };
+
+  // Register the affix plugin to execute on every window resize (and trigger)
+  $(window).on('resize', onresize).resize();
+
+  context.onunload = () => {
+    $(window).off('resize', onresize);
+  }
 }

From 71a510abe0bc1a1748352991412afa592d635f19 Mon Sep 17 00:00:00 2001
From: Franz Liedke <franz@develophp.org>
Date: Fri, 17 Feb 2017 00:19:33 +0100
Subject: [PATCH 2/2] Compile dist JS

---
 framework/core/js/forum/dist/app.js | 45 +++++++++++++++++++----------
 1 file changed, 29 insertions(+), 16 deletions(-)

diff --git a/framework/core/js/forum/dist/app.js b/framework/core/js/forum/dist/app.js
index a35c8a0b5..78bccf2ed 100644
--- a/framework/core/js/forum/dist/app.js
+++ b/framework/core/js/forum/dist/app.js
@@ -31146,29 +31146,42 @@ System.register('flarum/utils/abbreviateNumber', [], function (_export, _context
 System.register('flarum/utils/affixSidebar', [], function (_export, _context) {
   "use strict";
 
-  function affixSidebar(element, isInitialized) {
+  function affixSidebar(element, isInitialized, context) {
     var _this = this;
 
     if (isInitialized) return;
 
-    var $sidebar = $(element);
-    var $header = $('#header');
-    var $footer = $('#footer');
+    var onresize = function onresize() {
+      var $sidebar = $(element);
+      var $header = $('#header');
+      var $footer = $('#footer');
+      var $affixElement = $sidebar.find('> ul');
 
-    // Don't affix the sidebar if it is taller than the viewport (otherwise
-    // there would be no way to scroll through its content).
-    if ($sidebar.outerHeight(true) > $(window).height() - $header.outerHeight(true)) return;
+      $(window).off('.affix');
+      $affixElement.removeClass('affix affix-top affix-bottom').removeData('bs.affix');
 
-    $sidebar.find('> ul').affix({
-      offset: {
-        top: function top() {
-          return $sidebar.offset().top - $header.outerHeight(true) - parseInt($sidebar.css('margin-top'), 10);
-        },
-        bottom: function bottom() {
-          return _this.bottom = $footer.outerHeight(true);
+      // Don't affix the sidebar if it is taller than the viewport (otherwise
+      // there would be no way to scroll through its content).
+      if ($sidebar.outerHeight(true) > $(window).height() - $header.outerHeight(true)) return;
+
+      $affixElement.affix({
+        offset: {
+          top: function top() {
+            return $sidebar.offset().top - $header.outerHeight(true) - parseInt($sidebar.css('margin-top'), 10);
+          },
+          bottom: function bottom() {
+            return _this.bottom = $footer.outerHeight(true);
+          }
         }
-      }
-    });
+      });
+    };
+
+    // Register the affix plugin to execute on every window resize (and trigger)
+    $(window).on('resize', onresize).resize();
+
+    context.onunload = function () {
+      $(window).off('resize', onresize);
+    };
   }
 
   _export('default', affixSidebar);