[contacts] HTML5 Device integration proposal

This is a short and sweet proposal for low-level integration of the DAP
Contacts API [1] to the candidate HTML5 Device element [2] being defined in
WebApps.

The rationale for this proposal is that regardless of whether a web page
obtains address book data from either the programmatic method defined in [1]
or a HTMLDeviceElement-based method yet-to-be-fully-clarified in [2] it
should be capable of accessing any resulting contact data in a uniform way.

By providing a DOM-based method in [2], the 'contacts picker' (as
informatively described in [1] Appendix A) would be reusable for the
HTMLDeviceElement method without requiring that the 'contact search
notification' dialog to also be used in this approach. The result is one
less click for the user in the DOM-based approach.

The proposal for accessing Address Book information from the HTML5 Device
element goes like this:

<device type=people onchange="successContactFindCallback(this.data)">
<script type="text/javascript">
// Identical to the example provided in the Contacts API:
function successContactFindCallback(contacts) {
    // do something with resulting contact objects
    for (var i in contacts) alert(contacts[i].displayName);
    // ...
}
</script>

where: HTMLDeviceElement.data will always be of type Contact[] whenever H
TMLDeviceElement.type=='people'

This element would render on a web page similar to the file input element
except that it would load the 'contacts picker' on invocation by the user.
This is notably not a form-based control, though data resulting from this
control could be used to populate a web form.

Could additional Contact API find() parameters be provided from a web page
to the 'contacts picker' in the DOM-based approach as follows?

<device type=people
data-params="fields=name,emails;filter=Robert;updatedSince=2010-05-23T00:00:00Z"
onchange="successContactFindCallback(this.data)">

Any better ideas for the 'data-params' attribute that I used above
considering it's not currently a common HTML5Element attribute?  Perhaps
this attribute should be added to the HTMLDeviceElement interface in [2] or
maybe an existing HTMLElement attribute (such as 'accept') could be reused
for this purpose.

Finally, a logistical question: How much of this proposal, if useful, can be
included in the HTML5 Device document [1] vs. the Contacts API document [2]?

Any feedback would be much appreciated. I'm just throwing the ball up in the
air :-)


- Richard


[1] http://dev.w3.org/2009/dap/contacts/

[2] http://dev.w3.org/html5/html-device/