[whatwg] Menus, fallback, and backwards compatibility: ideas wanted

[Ian Hickson]

On Thu, 15 Dec 2005, Lachlan Hunt wrote:
> > 
> >    <form action="redirect.cgi">
> >     <menu type="commands">
> >      <menu label="Select site...">
> >       <select name="goto"
> >               onchange="if (this.options[this.selectedIndex].value)
> >                           location = this.options[this.selectedIndex].value">
> >        <option value="" selected="selected"> Select site: </option>
> >        <option value="http://www.apple.com/"> Apple </option>
> >        <option value="http://www.mozilla.org/"> Mozilla </option>
> >        <option value="http://www.opera.com/"> Opera </option>
> >       </select>
> >       <span><input type="submit" value="Go"></span>
> >      </menu>
> >     </menu>
> >    </form>
> 
> Ignoring this abuse of select as a navigational menu which would be 
> better handled with <a href>, that handles the following cases fine:
>  * Legacy UAs, with script
>  * Legacy UAs, without script
>  * New UAs, with script
> 
> But, because the button will be hidden, it doesn't handle new UAs, 
> without script.  They'll only be able to select the menu item, but 
> nothing will happen.

Good point. (Though I still think scripting being optional is something 
that will become less and less realistic as time progresses.)


> The original idea I posted in this thread was that selecting an option 
> would implicitly activate the associated submit button and that scripts 
> (if supported) could capture the onsubmit event and deal with it 
> appropriately. The idea is somewhat like having an implied command 
> attribute on the option elements pointing to the submit button.

The problem is determining when a <select> is a real <select> and when it 
is one of these "autosubmit" <select>s. (I don't want to add an attribute 
or something, because that would be almost legitimising this use.)


> > The <span></span> hides the <input> from the <menu>. The value="" 
> > hides that <option> from the menu.
> 
> What semantics does the span have in this case to make it do that?

None. What happens is that the semantics of <menu> are to only look at the 
element's direct children (with some fudging around for <li>s). The <span> 
is not special inside <menu>, so it (and its children) are ignored by the 
menu generation code.


> I think an attribute on the button that says this is the default action 
> to be performed when a menu item is selected and that it should not be 
> rendered by default would be better.

Hmm. We could do that, true... <button> and <input> have so many 
attributes already though... Hmm...

Hmm... how about this?:

    <form action="redirect.cgi">
     <menu type="commands autosubmit"> <!-- <<<< -->
      <menu label="Select site...">
       <select name="goto"
               onchange="if (this.options[this.selectedIndex].value)
                           location = this.options[this.selectedIndex].value">
        <option value="" selected="selected"> Select site: </option>
        <option value="http://www.apple.com/"> Apple </option>
        <option value="http://www.mozilla.org/"> Mozilla </option>
        <option value="http://www.opera.com/"> Opera </option>
       </select>
       <span><input type="submit" value="Go"></span>
      </menu>
     </menu>
    </form>

When a command is selected from a menu with type="autosubmit", and that 
command has an associated form (i.e. it is an <input>, <button>, or 
<option> whose 'form' DOM attribute is not null) then that form's 
submission behaviour must be invoked after the command completes.

Top-level (not in menus) <menu> elements then act as follows:

   type="commands":                 treat as toolbar
   type="commands autosubmit":      treat as toolbar, with autosubmit
   type="declare":                  hide
   type="declare autosubmit":       hide, with autosubmit
   other:                           treat as <ul>

When nested, the behaviour depends on the context. In a menu, if there is 
a "label" attribute then it creates a submenu. In a toolbar, if there is a 
"label" attribute then it creates a menu button. If there is no label 
attribute then it is treated as if its contents were there instead of the 
<menu>, but with an <hr> before and an <hr> after.

In addition, if "type" is either "autosubmit", "declare autosubmit", or 
"commands autosubmit", then the submenu/menu part/menu button has the 
autosubmit behaviour.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'