UDM 4 is valid XHTML, and in our judgement, meets the criteria for WAI Triple-A conformance.
There's a couple of quick and easy things you can do to bring down the filesize:
But the server-side configurations are largely self-optimising - they compile on the server to include only the necessary bits of client-side code for your particular configuration, and that brings the output filesize down to a practical minimum every time. You control how lean it is by selectively using or removing features:
The following table outlines each removable feature, how much code it uses, and how to disable that feature to make the applicable saving. Although each one only takes a small amount of code, they quickly add up to a worthwhile saving.
The exclamation marks indicate default features which are there to improve accessibility (!!) or usability (!), so those are the ones I'd be most reluctant to lose. Obviously each one of these will have some kind of impact, so please read the linked notes for each feature to help you decide whether you can do without it.
| Feature | Code | How to disable |
|---|---|---|
| Ad-hoc menu and menu-item classes | 2.5K | Each pair of classes uses this much code, so the most efficient thing is not to have any. |
| Horizontal navbar | 2K |
You can make this saving if you use
"vertical" navbar alignment instead.
|
| Menu repositioning (!) | 2K |
Set the reposition menus to stay inside the viewportvalue in the $um['behaviors'] (um.behaviors) array to "no"
|
| Navbar and menu indicator arrows (!) | 2K |
Set the menu indicator character/imagevalues in the $um['items'] (um.items) and $um['menuItems'] (um.menuItems)
arrays to "none". You can also save filesize with this
feature by using textual indicators instead of images.
|
| Menu dropshadows | 1K |
Set the shadow backgroundproperty in the $um['menus'] (um.menus) and
$um['menuClasses'] (um.menuClasses) arrays to
"none"
|
| Rigid horizontal overflow | 1K |
If you have a horizontal navbar, set the horizontal overflowproperty in the $um['list'] (um.list) array to "flexible"
|
| Keyboard navigation (!!) | 1K |
Remove the $um['keys'] array from your custom file;
this saving is in addition
to the size of the module script itself.
|
| Iframe shim | 0.5K |
Set the manage windowed controls for win/ievalue in the $um['behaviors'] (um.behaviors) array to
"hide" or "none"
|
| Select-element hiding | 0.5K |
Set the manage windowed controls for win/ievalue in the $um['behaviors'] (um.behaviors) array to
"iframe" or "none"
|
| Using images | 0.5K | Don't use any images; this saving is in addition to the size of the images themselves. |
With all optional features removed, the smallest configuration is 20K. But for best accessibility I would recommend keeping the keyboard navigation module (6K + 1K control scripting), which brings the total up to 27K. The largest typical configuration - a horizontal navbar with keyboard navigation, all optional features, and one pair of menu/item classes - is 39K.
The output code looks to the browser like regular javascript and CSS, so the files will be cached after their first use, along with any images you're using, unless a visitor has their browser set not to do that.
UDM 4 is valid XHTML, and in our judgement, meets the criteria for WAI Triple-A conformance.
