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RE: Proposal for using web intents for a print intent

From: Nilsson, Claes1 <Claes1.Nilsson@sonyericsson.com>
Date: Thu, 26 Jan 2012 16:53:30 +0100
To: Paul Kinlan <paulkinlan@google.com>, James Hawkins <jhawkins@chromium.org>
CC: Dave Raggett <dsr@w3.org>, "public-web-intents@w3.org" <public-web-intents@w3.org>
Message-ID: <6DFA1B20D858A14488A66D6EEDF26AA35D649A16A4@seldmbx03.corpusers.net>
Hi Paul and others,

This comes back to the issue on "what is a Service in the context of Web Intents?" that I highlighted in [1].

Furthermore, printing was an example and we should probably more have the use cases in [2] in focus. 

I see that we have two issues to discuss:

1. Broadening/extending the concept of Web Intents Service to allowing Services to be not only represented as web pages but also as services/devices dynamically discovered through some underlying low level discovery/communication mechanism such as UPnP or Bluetooth. These dynamic Services may or may not have a UI.
2. How to achieve a persistent communication/control relation between the Client web application and the Service.

So 1 means that the Web Intents framework implementation in the UA (optionally) should support:
- Access to common low level discovery/communication mechanisms such as UPnP and Bluetooth.
- Dynamic creation and registration of Web Intents Services.
Correct?

For 2 Dave proposes a "handler object" as payload, but Greg states this will not work based on the current definition on Intents payload. Paul suggests using HTML5 message channels and Service specific JSON protocols on this channel. As HTML5 Web Messaging is designed to support communication between two browsing contexts I wonder if this mechanisms can be used to communicate between the Client web application and a Service that is dynamically created by the Web Intents framework in the UA? Or should the UA dynamically create a browsing context representing the discovered Service in this case?

My view on the strength of Web Intents is that a Service could reside anywhere. The Client web application should not have to know anything about where the Service resides. So, if we look at the use case "Push Play" in [2] the TV could be found in the local network and discovered through UPnP but it could also be found through the global cloud. I assume that the TV Service (in Web Intents context) is dynamically created by the Web Intents implementation for the local case but how is it for a TV discovered through the cloud? Under all circumstances we want the Client application to be able to use the same commands/protocol irrespective of where the TV resides. 

Best regards
  Claes



[1] http://lists.w3.org/Archives/Public/public-web-intents/2012Jan/0035.html
[2] http://www.w3.org/wiki/WebIntents/Home_Discovery_and_Web_Intents



> -----Original Message-----
> From: Paul Kinlan [mailto:paulkinlan@google.com]
> Sent: den 26 januari 2012 03:46
> To: James Hawkins
> Cc: Dave Raggett; public-web-intents@w3.org
> Subject: Re: Proposal for using web intents for a print intent
> 
> My use case is for www.imagemator.com to have a print button where I
> can go and send the photo directly to Costco's web print service.
> 
> Not wanting to speak (but I will take a leap of judgement) for Claes
> and Dave, they want to be able to interact with the Device (I have a
> couple of partners that I work with that would like the same thing)
> directly and be able to manage the printer status, so that they can
> interact with the printer to recieve higher level notifications and
> also manage the print queue (perhaps to cancel a job) via the app and
> not an external manager app.
> 
> To this effect I think this can be done with the methods that we have
> been discussing in the past.
> 
> var channel = new MessageChannel();
> var port2 = channel.port2();
> var port1 = channel.port1();
> port2.onmessage = function(e) {
>   if(e.data.message == "notify") { .. }
>   if(e.data.message == "ready") { port1.postMessage({ "message" :
> "start_job", data: data, options: { media_size: "A4", "color" : true}
> });
> 
> };
> var intent = new Intent("http://webintents.org/print",
> "appiliation/x-printer-controler", channel.port1());
> window.navigator.startActivity(intent, function() { /* yay */ });
> 
> It has some message protocol nitty gritty, but you can abstract that
> in a higher level API.
> 
> I imagine I would use the Intent system to print as follows:
> 
> var urls = ["url1", "url2", "url3"]
> var intent = new Intent("http://webintents.org/print",
> "appiliation/pdf", urls]);
> window.navigator.startActivity(intent, function() { /* yay */ });
> 
> With costco being a handler, and just accepting the images I passed in.
> 
> 
> 
> On Wed, Jan 25, 2012 at 6:30 PM, James Hawkins <jhawkins@chromium.org>
> wrote:
> > OK I think we're getting closer.  Can you explain this in terms of
> example
> > client(s) and respective service(s)?
> >
> >
> > On Wed, Jan 25, 2012 at 6:28 PM, Paul Kinlan <paulkinlan@google.com>
> wrote:
> >>
> >> I know this email was a little more complex way of interacting with
> >> printing devices, but the simpler case is much like "share" intent
> >> where there a cloud based printing solutions that accept just a PDF
> or
> >> document, the theory being that you "print" a document and via
> >> webintents it sends it to an API or service that will render it to
> >> paper or something else that can than be mailed to someone.
> >>
> >> I always imagined it to be something like:
> >> +
> >>
> https://printonline.fedex.com/v2.3.0/?s_kwcid=TC|16501|print%20companie
> s||S|b|9706081275&&cmp=KNC-1000441-003-002-0950-0010000-US-US-EN-
> GPOL00000000000&x=1&s_kwcid=TC|16501|print%20companies||S|b|9706081275
> >> Or
> >> Costco's send to print images online and then collect them in the
> >> store
> >>
> (http://www.costcophotocenter.com/account/login.aspx?ReturnUrl=%2falbum
> %2f)
> >>
> >> The verb "save" and "share" doesn't quite fit the intention of the
> user.
> >>
> >> On Wed, Jan 25, 2012 at 6:07 PM, James Hawkins
> <jhawkins@chromium.org>
> >> wrote:
> >> > What is the use case for this?  What I'm really asking is what do
> you
> >> > need
> >> > that is not handled by existing browser printing, e.g.,
> window.print?
> >> >
> >> > Thanks,
> >> > James
> >> >
> >> > On Wed, Jan 25, 2012 at 3:51 AM, Dave Raggett <dsr@w3.org> wrote:
> >> >>
> >> >> I spotted an error in my example:
> >> >>
> >> >> On 25/01/12 11:40, Dave Raggett wrote:
> >> >>
> >> >> > // now start the activity and redirect
> >> >> > // the onSuccess, and onFail functions
> >> >> > // to methods on the intent data object
> >> >> >
> >> >> > window.navigator.startActivity(intent,
> >> >> >   function (data) { intent.success(data); },
> >> >> >   function (data) { intent.fail(data); }
> >> >> > );
> >> >>
> >> >> Should have been:
> >> >>
> >> >> window.navigator.startActivity(intent,
> >> >>  function (data) { intent.data.success(data); },
> >> >>  function (data) { intent.data.fail(data); }
> >> >> );
> >> >>
> >> >> sorry about that.
> >> >> --
> >> >> Dave Raggett <dsr@w3.org> http://www.w3.org/People/Raggett
> >> >>
> >> >
> >>
> >>
> >>
> >> --
> >> Paul Kinlan
> >> Developer Advocate @ Google for Chrome and HTML5
> >> G+: http://plus.ly/paul.kinlan
> >> t: +447730517944
> >> tw: @Paul_Kinlan
> >> LinkedIn: http://uk.linkedin.com/in/paulkinlan
> >> Blog: http://paul.kinlan.me
> >> Skype: paul.kinlan
> >
> >
> 
> 
> 
> --
> Paul Kinlan
> Developer Advocate @ Google for Chrome and HTML5
> G+: http://plus.ly/paul.kinlan
> t: +447730517944
> tw: @Paul_Kinlan
> LinkedIn: http://uk.linkedin.com/in/paulkinlan
> Blog: http://paul.kinlan.me
> Skype: paul.kinlan
Received on Thursday, 26 January 2012 15:53:58 GMT

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