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Re: [widgets] Seeking comments on Last Call WD of Widgets: APIs and Events spec; deadline 15 Sept 2009

From: Scott Wilson <scott.bradley.wilson@gmail.com>
Date: Wed, 19 Aug 2009 11:42:59 +0100
Message-Id: <EB2880F1-7EAC-4DA4-9791-0CC634E6B26B@gmail.com>
To: public-webapps WG <public-webapps@w3.org>
First off, a nice easily-remedied typo:

2. Definitions

"Author script
An script running within the widget context (e.g., some ECMAScript)."

Should be "A" not "An"

Second, a more thorny issue:

5. Storage Areas
"A storage area is a data-store that is unique for the origin of a  
widget, which a user agent can use to store string-based key-value  
pairs."

The storage area must be unique to the instance of a widget. Otherwise  
this will lead to widget instances overwriting each others' preference  
settings, or exposing personal preferences to other users who happen  
to be using the same type of widget. (There's a discussion of this on  
the list somewhere).

However, given the definition of origin in the document, the current  
text may be a problem:

"The universally unique identity of a widget represented as a URI,  
established via the rules defined in the [Widgets-URI] specification."

Now by "widget" do the spec actually mean the widget instance, or what  
you might think of as the widget's "class" or prototype?

The latter would seem to be the case given a read of the Widgets URI  
scheme draft [1], in which case, the Origin is not going to work for  
associating a storage area unless the UA is single-user and doesn't  
allow widgets to be instantiated multiple times.

(E.g. Apache Wookie (Incubating) mints a UID when a widget is  
instantiated for a particular user in a particular application context  
(e.g. user "bob" puts the "weather" widget onto their "profile page"),  
and uses this UID to associate a storage area with the widget  
instance. The widget id URI as found in config.xml->id is used along  
with application context and user data to generate the hash for the  
UID. Now, is Wookie's UID the "origin" as far as A&E is concerned, or  
is it the canonical widget id?)

Also:
"A user agents should limit the total amount of space allowed for  
storage areas. An arbitrary limit of five megabytes per origin of a  
widget is recommended."

Again we have the same issue - 5Mb per origin isn't great if you have  
1,000,000 instances of a widget with the same origin. Instead, limits  
should be considered to be per widget instance, or origin needs to be  
clearly defined in terms of instances.

So either "origin" needs clarification as referring to widget  
instances, or storage areas need to be defined in terms of instances  
and not necessarily the origin - in which case the dependency of the  
A&E spec on [1] can be removed.
-S

[1] http://www.w3.org/TR/widgets-uri/

On 19 Aug 2009, at 04:40, Arthur Barstow wrote:

> On August 18 a Last Call Working Draft of the Widgets: APIs and  
> Events spec was published:
>
> <http://www.w3.org/TR/2009/WD-widgets-apis-20090818/>
>
> Please send comments to public-webapps@w3.org by September 15 at the  
> latest.
>
> As Marcos noted at [1], the title is misleading since the spec no  
> longer defines Events. This error will be corrected before the  
> document's next publication.
>
> -Regards, Art Barstow
>
> [1] http://lists.w3.org/Archives/Public/public-webapps/2009JulSep/0646.html
>
>



Received on Wednesday, 19 August 2009 10:43:37 GMT

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