Near complete rewrite of sidebars JS for reliability:

- Refactored as JavaScript classes.

- Everything is now scoped to behaviours without references to instances
  outside of said behaviours; this is primarily achieved by
  instantiating classes and assigning them to a property on elements we
  attach to, and then destroyed when the behaviour detaches.

- Did I mention hella object-oriented?

See: neurocracy/omnipedia#46

javascript/sidebars.focus.js

@@ -10,13 +10,15 @@
 // - 'omnipediaSidebarsMenuClose': will move focus to the menu open control if
 // sidebars are off-canvas.
 
+AmbientImpact.onGlobals([
+ 'ally.query.tabbable',
+], function() {
 AmbientImpact.on([
- 'OmnipediaSiteThemeSidebarsElements',
- 'OmnipediaSiteThemeSidebarsState',
+ 'OmnipediaSiteThemeSidebars',
  'pointerFocusHide',
-], function(sidebarsElements, sidebarsState, aiPointerFocusHide, $) {
+], function(sidebars, aiPointerFocusHide, $) {
 AmbientImpact.addComponent('OmnipediaSiteThemeSidebarsFocus', function(
- sidebarsFocus, $
+ sidebarsFocus, $,
 ) {
 
  'use strict';
@@ -31,47 +33,53 @@ AmbientImpact.addComponent('OmnipediaSiteThemeSidebarsFocus', function(
  this.addBehaviour(
  'OmnipediaSiteThemeSidebarsFocus',
  'omnipedia-site-theme-sidebars-focus',
- sidebarsElements.getSidebarsBehaviourSelector(),
+ 'body',
  function(context, settings) {
 
- $(this).on(
- 'omnipediaSidebarsMenuOpen.' + eventNamespace,
- function(event) {
+ $(this).on(`omnipediaSidebarsMenuOpen.${eventNamespace}`, function(
+ event, instance,
+ ) {
 
- if (sidebarsState.isOffCanvas() === true) {
-
- aiPointerFocusHide.lock();
-
- sidebarsElements.getSidebarsContainer().focus();
+ if (instance.isOffCanvas() !== true) {
+ return;
+ }
 
-  aiPointerFocusHide.unlock();
+ aiPointerFocusHide.lock();
 
- }
+ $(ally.query.tabbable({
+ context: instance.$sidebars,
+ includeContext: true,
+ })).first().focus();
 
- }).on('omnipediaSidebarsMenuClose.' + eventNamespace, function(event) {
+  aiPointerFocusHide.unlock();
 
- if (sidebarsState.isOffCanvas() === true) {
+ }).on(`omnipediaSidebarsMenuClose.${eventNamespace}`, function(
+ event, instance,
+ ) {
 
- aiPointerFocusHide.lock();
+ if (instance.isOffCanvas() !== true) {
+ return;
+ }
 
-  sidebarsElements.getSidebarsMenuOpen().focus();
+ aiPointerFocusHide.lock();
 
-  aiPointerFocusHide.unlock();
+ instance.$menuOpen.focus();
 
- }
+ aiPointerFocusHide.unlock();
 
  });
 
  },
  function(context, settings, trigger) {
 
  $(this).off([
- 'omnipediaSidebarsMenuOpen.' + eventNamespace,
- 'omnipediaSidebarsMenuClose.' + eventNamespace,
+ `omnipediaSidebarsMenuOpen.${eventNamespace}`,
+ `omnipediaSidebarsMenuClose.${eventNamespace}`,
  ].join(' '));
 
  }
  );
 
 });
 });
+});