function checkAsideExpose() {
        var mq = $attr.exposeAsideWhen == 'large' ? '(min-width:768px)' : $attr.exposeAsideWhen;
        sideMenuCtrl.exposeAside($window.matchMedia(mq).matches);
        sideMenuCtrl.activeAsideResizing(false);
      }
@ngdoc directive
@name exposeAsideWhen
@module ionic
@restrict A
@parent ionic.directive:ionSideMenus

@description
It is common for a tablet application to hide a menu when in portrait mode, but to show the
same menu on the left side when the tablet is in landscape mode. The `exposeAsideWhen` attribute
directive can be used to accomplish a similar interface.

By default, side menus are hidden underneath its side menu content, and can be opened by either
swiping the content left or right, or toggling a button to show the side menu. However, by adding the
`exposeAsideWhen` attribute directive to an {@link ionic.directive:ionSideMenu} element directive,
a side menu can be given instructions on "when" the menu should be exposed (always viewable). For
example, the `expose-aside-when="large"` attribute will keep the side menu hidden when the viewport's
width is less than `768px`, but when the viewport's width is `768px` or greater, the menu will then
always be shown and can no longer be opened or closed like it could when it was hidden for smaller
viewports.

Using `large` as the attribute's value is a shortcut value to `(min-width:768px)` since it is
the most common use-case. However, for added flexibility, any valid media query could be added
as the value, such as `(min-width:600px)` or even multiple queries such as
`(min-width:750px) and (max-width:1200px)`.
@usage
```html
<ion-side-menus>
  <!-- Center content -->
  <ion-side-menu-content>
  </ion-side-menu-content>

  <!-- Left menu -->
  <ion-side-menu expose-aside-when="large">
  </ion-side-menu>
</ion-side-menus>
```
For a complete side menu example, see the
{@link ionic.directive:ionSideMenus} documentation.