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RE: [widgets] What does it mean to have an unavailable API

From: Marcin Hanclik <Marcin.Hanclik@access-company.com>
Date: Wed, 3 Jun 2009 12:13:32 +0200
To: Scott Wilson <scott.bradley.wilson@gmail.com>
CC: Henri Sivonen <hsivonen@iki.fi>, public-webapps <public-webapps@w3.org>
Message-ID: <FAA1D89C5BAF1142A74AF116630A9F2C0A26ED909D@OBEEX01.obe.access-company.com>
Hi Scott,

>>I can see the UC for requestFeature, though its not something we'd
>>ever expect to use - we'd stick to just static feature declarations,
>>as we have no way of injecting scripts into instances after they've
>>already launched.
There is an ongoing debate about requestFeature().
BONDI spec is approaching both widgets and websites and basically requestFeature() is planned to be primarily used only by websites.
requestFeature() is present in general WebIDL, we may need some prose in case its use is constrained.
The next debate on this topic in BONDI is planned to happen soon.
The output will definitely by provided to this mailing list asap, I assume.

Thanks.

Kind regards,
Marcin

Marcin Hanclik
ACCESS Systems Germany GmbH
Tel: +49-208-8290-6452  |  Fax: +49-208-8290-6465
Mobile: +49-163-8290-646
E-Mail: marcin.hanclik@access-company.com

-----Original Message-----
From: Scott Wilson [mailto:scott.bradley.wilson@gmail.com]
Sent: Tuesday, June 02, 2009 5:41 PM
To: Marcin Hanclik
Cc: Henri Sivonen; public-webapps
Subject: Re: [widgets] What does it mean to have an unavailable API

Hi Marcin,

Yes, on (1); the Google example I was referring to does the same. So,
for example, "analytics" is the feature name, but this means the whole
module, which includes a couple of JS libs and a range of functions.

For hasFeature() the only UC I can see is if your Widget declares a
Feature, but doesn't require it (REQUIRED=false), but can make use of
it for added functionality if it is available.  (Sorry Marcos, just
remembered this one - don't get rid of hasFeature() yet!)

I can see the UC for requestFeature, though its not something we'd
ever expect to use - we'd stick to just static feature declarations,
as we have no way of injecting scripts into instances after they've
already launched.

S

On 2 Jun 2009, at 15:28, Marcin Hanclik wrote:

> Hi Scott,
>
> In BONDI we have discussed the (has/request)Feature() for some time.
> http://bondi.omtp.org/1.0/security/BONDI_Architecture_and_Security_v1.0.pdf
> , section 4.3
>
> A few points for further discussion:
> 1. feature (at least in BONDI) is an abstract thing, not just one
> function. So hasFeature() is simply optimized checking procedure. If
> you check for a feature and discover that it is available, you may/
> should/must assume that a set of functions is available. Otherwise,
> you have to check each function individually and basically you
> cannot assume that if one functions is available, then the other is
> as well.
>
> 2. requestFeature() adds dynamism to the Website content. Widgets
> express their dependency statically by <feature>.
> http://bondi.omtp.org/1.0/security/BONDI_Architecture_and_Security_Appendices_v1.0.pdf
>  B.2 specifies more details.
>
> Thanks.
>
> Kind regards,
> Marcin
>
> Marcin Hanclik
> ACCESS Systems Germany GmbH
> Tel: +49-208-8290-6452  |  Fax: +49-208-8290-6465
> Mobile: +49-163-8290-646
> E-Mail: marcin.hanclik@access-company.com
>
> -----Original Message-----
> From: public-webapps-request@w3.org [mailto:public-webapps-request@w3.org
> ] On Behalf Of Scott Wilson
> Sent: Tuesday, June 02, 2009 3:18 PM
> To: Henri Sivonen
> Cc: public-webapps
> Subject: Re: [widgets] What does it mean to have an unavailable API
>
> I think in such a case the UA should not be expected to make frob()
> available, and the Widget should not expect frob() to be present.
>
> For example, in the Shindig opensocial runtime, client JS is injected
> based on the <require> elements of the gadget. If it isn't declared,
> it isn't injected, and if you try calling those functions they just
> aren't there.
>
> What this does make less clear for me is in W:A&E why you'd ever want
> to call "hasFeature()"?
>
> S
>
>
> On 2 Jun 2009, at 13:51, Henri Sivonen wrote:
>
>>>
>>> Ok. I see what you mean. Widget.hasFeature has slightly different
>>> semantics (in widgets, it means "did that feature I requested load
>>> and become available?"
>>
>> Which brings up the issue that it's unclear what it means for an API
>> to have latent support but not having been activated with <feature>.
>>
>> If a widget UA has an implementation for window.frob() and frob()
>> requires <feature> activation, what should happen when frob() hasn't
>> been activated with <feature>? Should there be no function object
>> for frob()? Or should it be there but throw upon calling? Or
>> something else.
>>
>> Please specify this.
>>
>> --
>> Henri Sivonen
>> hsivonen@iki.fi
>> http://hsivonen.iki.fi/
>>
>>
>>
>
>
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>
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>
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>
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Access Systems Germany GmbH
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Received on Wednesday, 3 June 2009 10:14:27 GMT

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